[0.60.2] Bump version numbers

Summary:
Looks we forgot to add this file to publish list. By adding it, we can remove some code in CLI that special-cases `react-native` package, since it now announces itself as a proper platform.

cc kelset, we'd like to have this cherry-picked for 0.60.

## Changelog

[Internal] [Fixed] - Publish `react-native.config.js`
Pull Request resolved: https://github.com/facebook/react-native/pull/25436

Test Plan: `npm pack` shows `react-native.config.js`

Differential Revision: D16071113

Pulled By: cpojer

fbshipit-source-id: df18affbb9a0ad7f2cfdd1a4cc93191aa5ffadeb

.circleci/config.yml

@@ -157,7 +157,7 @@ js_defaults: &js_defaults
 android_defaults: &android_defaults
   <<: *defaults
   docker:
-    - image: reactnativecommunity/react-native-android:2019-5-7
+    - image: reactnativecommunity/react-native-android:2019-5-29
   resource_class: "large"
   environment:
     - TERM: "dumb"
@@ -544,10 +544,9 @@ jobs:
 
       # Keep configuring Android dependencies while AVD boots up
 
-      # Install Buck
       - restore-cache: *restore-buck-downloads-cache
       - run:
-          name: Install BUCK
+          name: Install Buck
           command: |
             buck --version
             # Install related tooling
@@ -684,9 +683,6 @@ jobs:
       - restore-cache: *restore-gradle-downloads-cache
       - run: *download-dependencies-gradle
 
-      - restore-cache: *restore-yarn-cache
-      - run: *yarn
-
       - run:
           name: Authenticate with npm
           command: echo "//registry.npmjs.org/:_authToken=${CIRCLE_NPM_TOKEN}" > ~/.npmrc
@@ -727,8 +723,12 @@ workflows:
 
   releases:
     jobs:
+      - checkout_code:
+          filters: *filter-only-version-tags
       - publish_npm_package:
           filters: *filter-only-version-tags
+          requires:
+            - checkout_code
 
   analysis:
     jobs:

Libraries/Components/ScrollView/ScrollView.js

@@ -25,6 +25,7 @@ const invariant = require('invariant');
 const processDecelerationRate = require('./processDecelerationRate');
 const requireNativeComponent = require('../../ReactNative/requireNativeComponent');
 const resolveAssetSource = require('../../Image/resolveAssetSource');
+const splitLayoutProps = require('../../StyleSheet/splitLayoutProps');
 
 import type {
   PressEvent,
@@ -1125,15 +1126,15 @@ class ScrollView extends React.Component<Props, State> {
         // On Android wrap the ScrollView with a AndroidSwipeRefreshLayout.
         // Since the ScrollView is wrapped add the style props to the
         // AndroidSwipeRefreshLayout and use flex: 1 for the ScrollView.
-        // Note: we should only apply props.style on the wrapper
+        // Note: we should split props.style on the inner and outer props
         // however, the ScrollView still needs the baseStyle to be scrollable
-
+        const {outer, inner} = splitLayoutProps(flattenStyle(props.style));
         return React.cloneElement(
           refreshControl,
-          {style: props.style},
+          {style: [baseStyle, outer]},
           <ScrollViewClass
             {...props}
-            style={baseStyle}
+            style={[baseStyle, inner]}
             // $FlowFixMe
             ref={this._setScrollViewRef}>
             {contentContainer}

Libraries/Core/ReactNativeVersion.js

@@ -1,17 +1,17 @@
 /**
+ * @generated by scripts/bump-oss-version.js
+ *
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @format
- * @generated by scripts/bump-oss-version.js
  * @flow
  */
 
 exports.version = {
   major: 0,
-  minor: 0,
-  patch: 0,
+  minor: 60,
+  patch: 2,
   prerelease: null,
 };

Libraries/Core/setUpGlobals.js

@@ -21,6 +21,10 @@ if (global.window === undefined) {
   global.window = global;
 }
 
+if (global.self === undefined) {
+  global.self = global;
+}
+
 // Set up process
 global.process = global.process || {};
 global.process.env = global.process.env || {};

Libraries/Network/fetch.js

@@ -11,7 +11,7 @@
 
 'use strict';
 
-const whatwg = require('../vendor/core/whatwg-fetch');
+const whatwg = require('whatwg-fetch');
 
 if (whatwg && whatwg.fetch) {
   module.exports = whatwg;

Libraries/NewAppScreen/components/DebugInstructions.js

@@ -27,7 +27,7 @@ const DebugInstructions = Platform.select({
   ),
   default: () => (
     <Text>
-      Press <Text style={styles.highlight}>menu button</Text> or
+      Press <Text style={styles.highlight}>menu button</Text> or{' '}
       <Text style={styles.highlight}>Shake</Text> your device to open the React
       Native debug menu.
     </Text>

Libraries/StyleSheet/__tests__/splitLayoutProps-test.js

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @emails oncall+react_native
+ */
+
+'use strict';
+
+const splitLayoutProps = require('../splitLayoutProps');
+
+test('splits style objects', () => {
+  const style = {width: 10, margin: 20, padding: 30};
+  const {outer, inner} = splitLayoutProps(style);
+  expect(outer).toMatchInlineSnapshot(`
+    Object {
+      "margin": 20,
+      "width": 10,
+    }
+  `);
+  expect(inner).toMatchInlineSnapshot(`
+    Object {
+      "padding": 30,
+    }
+  `);
+});
+
+test('does not copy values to both returned objects', () => {
+  const style = {marginVertical: 5, paddingHorizontal: 10};
+  const {outer, inner} = splitLayoutProps(style);
+  expect(outer).toMatchInlineSnapshot(`
+    Object {
+      "marginVertical": 5,
+    }
+  `);
+  expect(inner).toMatchInlineSnapshot(`
+    Object {
+      "paddingHorizontal": 10,
+    }
+  `);
+});

Libraries/StyleSheet/splitLayoutProps.js

@@ -0,0 +1,62 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @flow strict-local
+ */
+
+'use strict';
+
+import type {DangerouslyImpreciseStyle} from './StyleSheet';
+
+const OUTER_PROPS = Object.assign(Object.create(null), {
+  margin: true,
+  marginHorizontal: true,
+  marginVertical: true,
+  marginBottom: true,
+  marginTop: true,
+  marginLeft: true,
+  marginRight: true,
+  flex: true,
+  flexGrow: true,
+  flexShrink: true,
+  flexBasis: true,
+  alignSelf: true,
+  height: true,
+  minHeight: true,
+  maxHeight: true,
+  width: true,
+  minWidth: true,
+  maxWidth: true,
+  position: true,
+  left: true,
+  right: true,
+  bottom: true,
+  top: true,
+});
+
+function splitLayoutProps(
+  props: ?DangerouslyImpreciseStyle,
+): {
+  outer: DangerouslyImpreciseStyle,
+  inner: DangerouslyImpreciseStyle,
+} {
+  const inner = {};
+  const outer = {};
+  if (props) {
+    Object.keys(props).forEach(k => {
+      const value: $ElementType<DangerouslyImpreciseStyle, typeof k> = props[k];
+      if (OUTER_PROPS[k]) {
+        outer[k] = value;
+      } else {
+        inner[k] = value;
+      }
+    });
+  }
+  return {outer, inner};
+}
+
+module.exports = splitLayoutProps;

Libraries/Text/RCTText.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		19461666225DC3B300E4E008 /* RCTTextRenderer.m in Sources */ = {isa = PBXBuildFile; fileRef = 19461664225DC3B300E4E008 /* RCTTextRenderer.m */; };
 		5956B130200FEBAA008D9D16 /* RCTRawTextShadowView.m in Sources */ = {isa = PBXBuildFile; fileRef = 5956B0FD200FEBA9008D9D16 /* RCTRawTextShadowView.m */; };
 		5956B131200FEBAA008D9D16 /* RCTRawTextViewManager.m in Sources */ = {isa = PBXBuildFile; fileRef = 5956B0FE200FEBA9008D9D16 /* RCTRawTextViewManager.m */; };
 		5956B132200FEBAA008D9D16 /* RCTSinglelineTextInputView.m in Sources */ = {isa = PBXBuildFile; fileRef = 5956B101200FEBA9008D9D16 /* RCTSinglelineTextInputView.m */; };
@@ -187,6 +188,8 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		19461664225DC3B300E4E008 /* RCTTextRenderer.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = RCTTextRenderer.m; sourceTree = "<group>"; };
+		19461665225DC3B300E4E008 /* RCTTextRenderer.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RCTTextRenderer.h; sourceTree = "<group>"; };
 		2D2A287B1D9B048500D4039D /* libRCTText-tvOS.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libRCTText-tvOS.a"; sourceTree = BUILT_PRODUCTS_DIR; };
 		58B5119B1A9E6C1200147676 /* libRCTText.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = libRCTText.a; sourceTree = BUILT_PRODUCTS_DIR; };
 		5956B0F9200FEBA9008D9D16 /* RCTConvert+Text.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "RCTConvert+Text.h"; sourceTree = "<group>"; };
@@ -360,6 +363,8 @@
 			children = (
 				5956B129200FEBAA008D9D16 /* NSTextStorage+FontScaling.h */,
 				5956B125200FEBAA008D9D16 /* NSTextStorage+FontScaling.m */,
+				19461665225DC3B300E4E008 /* RCTTextRenderer.h */,
+				19461664225DC3B300E4E008 /* RCTTextRenderer.m */,
 				5956B126200FEBAA008D9D16 /* RCTTextShadowView.h */,
 				5956B122200FEBAA008D9D16 /* RCTTextShadowView.m */,
 				5956B123200FEBAA008D9D16 /* RCTTextView.h */,
@@ -439,6 +444,7 @@
 			developmentRegion = English;
 			hasScannedForEncodings = 0;
 			knownRegions = (
+				English,
 				en,
 			);
 			mainGroup = 58B511921A9E6C1200147676;
@@ -504,6 +510,7 @@
 				5956B142200FEBAA008D9D16 /* RCTTextViewManager.m in Sources */,
 				5956B135200FEBAA008D9D16 /* RCTBaseTextInputView.m in Sources */,
 				5956B144200FEBAA008D9D16 /* RCTVirtualTextViewManager.m in Sources */,
+				19461666225DC3B300E4E008 /* RCTTextRenderer.m in Sources */,
 				5C245F39205E216A00D936E9 /* RCTInputAccessoryShadowView.m in Sources */,
 				5956B13B200FEBAA008D9D16 /* RCTMultilineTextInputViewManager.m in Sources */,
 				5956B134200FEBAA008D9D16 /* RCTSinglelineTextInputViewManager.m in Sources */,

Libraries/Text/Text/RCTTextRenderer.h

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import <UIKit/UIKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * Used by text layers to render text. Note that UIKit crashes if this delegate is implemented
+ * directly on a UIView subclass since it already implements it for the view's root
+ * layer. This is why this is implemented in a separate class.
+ */
+@interface RCTTextRenderer : NSObject <CALayerDelegate>
+
+- (void)setTextStorage:(NSTextStorage *)textStorage contentFrame:(CGRect)contentFrame;
+
+@end
+
+NS_ASSUME_NONNULL_END

Libraries/Text/Text/RCTTextRenderer.m

@@ -0,0 +1,56 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import "RCTTextRenderer.h"
+
+#import "RCTTextAttributes.h"
+
+@implementation RCTTextRenderer
+{
+  NSTextStorage *_Nullable _textStorage;
+  CGRect _contentFrame;
+}
+
+- (void)setTextStorage:(NSTextStorage *)textStorage
+          contentFrame:(CGRect)contentFrame
+{
+  _textStorage = textStorage;
+  _contentFrame = contentFrame;
+}
+
+- (void)drawLayer:(CALayer *)layer
+        inContext:(CGContextRef)ctx;
+{
+  if (!_textStorage) {
+    return;
+  }
+
+  CGRect boundingBox = CGContextGetClipBoundingBox(ctx);
+  CGContextSaveGState(ctx);
+  UIGraphicsPushContext(ctx);
+
+  NSLayoutManager *layoutManager = _textStorage.layoutManagers.firstObject;
+  NSTextContainer *textContainer = layoutManager.textContainers.firstObject;
+
+  NSRange glyphRange =
+  [layoutManager glyphRangeForBoundingRect:boundingBox
+                           inTextContainer:textContainer];
+
+  [layoutManager drawBackgroundForGlyphRange:glyphRange atPoint:_contentFrame.origin];
+  [layoutManager drawGlyphsForGlyphRange:glyphRange atPoint:_contentFrame.origin];
+
+  UIGraphicsPopContext();
+  CGContextRestoreGState(ctx);
+}
+
+- (id<CAAction>)actionForLayer:(CALayer *)layer forKey:(NSString *)event
+{
+  // Disable all implicit animations.
+  return (id)[NSNull null];
+}
+
+@end

Libraries/Text/Text/RCTTextView.m

@@ -13,15 +13,36 @@
 #import <React/UIView+React.h>
 
 #import "RCTTextShadowView.h"
+#import "RCTTextRenderer.h"
+
+@interface RCTTextTiledLayer : CATiledLayer
+
+@end
+
+@implementation RCTTextTiledLayer
+
++ (CFTimeInterval)fadeDuration
+{
+  return 0.05;
+}
+
+@end
 
 @implementation RCTTextView
 {
-  CAShapeLayer *_highlightLayer;
   UILongPressGestureRecognizer *_longPressGestureRecognizer;
 
   NSArray<UIView *> *_Nullable _descendantViews;
   NSTextStorage *_Nullable _textStorage;
   CGRect _contentFrame;
+  RCTTextRenderer *_renderer;
+  // For small amount of text avoid the overhead of CATiledLayer and
+  // make render text synchronously. For large amount of text, use
+  // CATiledLayer to chunk text rendering and avoid linear memory
+  // usage.
+  CALayer *_Nullable _syncLayer;
+  RCTTextTiledLayer *_Nullable _asyncTiledLayer;
+  CAShapeLayer *_highlightLayer;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame
@@ -31,6 +52,7 @@
     self.accessibilityTraits |= UIAccessibilityTraitStaticText;
     self.opaque = NO;
     self.contentMode = UIViewContentModeRedraw;
+    _renderer = [RCTTextRenderer new];
   }
   return self;
 }
@@ -65,6 +87,7 @@
   // This disables the frame animation, without affecting opacity, etc.
   [UIView performWithoutAnimation:^{
     [super reactSetFrame:frame];
+    [self configureLayer];
   }];
 }
 
@@ -91,55 +114,101 @@
     [self addSubview:view];
   }
 
-  [self setNeedsDisplay];
+  [_renderer setTextStorage:textStorage contentFrame:contentFrame];
+  [self configureLayer];
+  [self setCurrentLayerNeedsDisplay];
 }
 
-- (void)drawRect:(CGRect)rect
+- (void)configureLayer
 {
   if (!_textStorage) {
     return;
   }
 
+  CALayer *currentLayer;
+
+  CGSize screenSize = RCTScreenSize();
+  CGFloat textViewTileSize =  MAX(screenSize.width, screenSize.height) * 1.5;
+
+  if (self.frame.size.width > textViewTileSize || self.frame.size.height > textViewTileSize) {
+    // Cleanup sync layer
+    if (_syncLayer != nil) {
+      _syncLayer.delegate = nil;
+      [_syncLayer removeFromSuperlayer];
+      _syncLayer = nil;
+    }
+
+    if (_asyncTiledLayer == nil) {
+      RCTTextTiledLayer *layer = [RCTTextTiledLayer layer];
+      layer.delegate = _renderer;
+      layer.contentsScale = RCTScreenScale();
+      layer.tileSize = CGSizeMake(textViewTileSize, textViewTileSize);
+      _asyncTiledLayer = layer;
+      [self.layer addSublayer:layer];
+      [layer setNeedsDisplay];
+    }
+    _asyncTiledLayer.frame = self.bounds;
+    currentLayer = _asyncTiledLayer;
+  } else {
+    // Cleanup async tiled layer
+    if (_asyncTiledLayer != nil) {
+      _asyncTiledLayer.delegate = nil;
+      [_asyncTiledLayer removeFromSuperlayer];
+      _asyncTiledLayer = nil;
+    }
+
+    if (_syncLayer == nil) {
+      CALayer *layer = [CALayer layer];
+      layer.delegate = _renderer;
+      layer.contentsScale = RCTScreenScale();
+      _syncLayer = layer;
+      [self.layer addSublayer:layer];
+      [layer setNeedsDisplay];
+    }
+    _syncLayer.frame = self.bounds;
+    currentLayer = _syncLayer;
+  }
 
   NSLayoutManager *layoutManager = _textStorage.layoutManagers.firstObject;
   NSTextContainer *textContainer = layoutManager.textContainers.firstObject;
-
-  NSRange glyphRange = [layoutManager glyphRangeForTextContainer:textContainer];
-  [layoutManager drawBackgroundForGlyphRange:glyphRange atPoint:_contentFrame.origin];
-  [layoutManager drawGlyphsForGlyphRange:glyphRange atPoint:_contentFrame.origin];
+  NSRange glyphRange =
+    [layoutManager glyphRangeForTextContainer:textContainer];
 
   __block UIBezierPath *highlightPath = nil;
   NSRange characterRange = [layoutManager characterRangeForGlyphRange:glyphRange
                                                      actualGlyphRange:NULL];
+
   [_textStorage enumerateAttribute:RCTTextAttributesIsHighlightedAttributeName
                            inRange:characterRange
                            options:0
                         usingBlock:
-    ^(NSNumber *value, NSRange range, __unused BOOL *stop) {
-      if (!value.boolValue) {
-        return;
-      }
+   ^(NSNumber *value, NSRange range, __unused BOOL *stop) {
+     if (!value.boolValue) {
+       return;
+     }
 
-      [layoutManager enumerateEnclosingRectsForGlyphRange:range
-                                 withinSelectedGlyphRange:range
-                                          inTextContainer:textContainer
-                                               usingBlock:
-        ^(CGRect enclosingRect, __unused BOOL *anotherStop) {
-          UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectInset(enclosingRect, -2, -2) cornerRadius:2];
-          if (highlightPath) {
-            [highlightPath appendPath:path];
-          } else {
-            highlightPath = path;
-          }
+     [layoutManager enumerateEnclosingRectsForGlyphRange:range
+                                withinSelectedGlyphRange:range
+                                         inTextContainer:textContainer
+                                              usingBlock:
+      ^(CGRect enclosingRect, __unused BOOL *anotherStop) {
+        UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectInset(enclosingRect, -2, -2) cornerRadius:2];
+        if (highlightPath) {
+          [highlightPath appendPath:path];
+        } else {
+          highlightPath = path;
         }
+      }
       ];
-  }];
+   }];
 
   if (highlightPath) {
     if (!_highlightLayer) {
       _highlightLayer = [CAShapeLayer layer];
       _highlightLayer.fillColor = [UIColor colorWithWhite:0 alpha:0.25].CGColor;
-      [self.layer addSublayer:_highlightLayer];
+    }
+    if (![currentLayer.sublayers containsObject:_highlightLayer]) {
+      [currentLayer addSublayer:_highlightLayer];
     }
     _highlightLayer.position = _contentFrame.origin;
     _highlightLayer.path = highlightPath.CGPath;
@@ -149,6 +218,15 @@
   }
 }
 
+- (void)setCurrentLayerNeedsDisplay
+{
+  if (_asyncTiledLayer != nil) {
+    [_asyncTiledLayer setNeedsDisplay];
+  } else if (_syncLayer != nil) {
+    [_syncLayer setNeedsDisplay];
+  }
+  [_highlightLayer setNeedsDisplay];
+}
 
 - (NSNumber *)reactTagAtPoint:(CGPoint)point
 {
@@ -174,14 +252,18 @@
 {
   [super didMoveToWindow];
 
+  // When an `RCTText` instance moves offscreen (possibly due to parent clipping),
+  // we unset the layer's contents until it comes onscreen again.
   if (!self.window) {
-    self.layer.contents = nil;
-    if (_highlightLayer) {
-      [_highlightLayer removeFromSuperlayer];
-      _highlightLayer = nil;
-    }
+    [_syncLayer removeFromSuperlayer];
+    _syncLayer = nil;
+    [_asyncTiledLayer removeFromSuperlayer];
+    _asyncTiledLayer = nil;
+    [_highlightLayer removeFromSuperlayer];
+    _highlightLayer = nil;
   } else if (_textStorage) {
-    [self setNeedsDisplay];
+    [self configureLayer];
+    [self setCurrentLayerNeedsDisplay];
   }
 }
 

Libraries/vendor/core/whatwg-fetch.js

@@ -1,533 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @format
- */
-
-// Fork of https://github.com/github/fetch/blob/master/fetch.js that does not
-// use reponseType: 'blob' by default. RN already has specific native implementations
-// for different response types so there is no need to add the extra blob overhead.
-
-// Copyright (c) 2014-2016 GitHub, Inc.
-//
-// Permission is hereby granted, free of charge, to any person obtaining
-// a copy of this software and associated documentation files (the
-// "Software"), to deal in the Software without restriction, including
-// without limitation the rights to use, copy, modify, merge, publish,
-// distribute, sublicense, and/or sell copies of the Software, and to
-// permit persons to whom the Software is furnished to do so, subject to
-// the following conditions:
-//
-// The above copyright notice and this permission notice shall be
-// included in all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
-// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-(function(self) {
-  'use strict';
-
-  if (self.fetch) {
-    return;
-  }
-
-  var support = {
-    searchParams: 'URLSearchParams' in self,
-    iterable: 'Symbol' in self && 'iterator' in Symbol,
-    blob:
-      'FileReader' in self &&
-      'Blob' in self &&
-      (function() {
-        try {
-          new Blob();
-          return true;
-        } catch (e) {
-          return false;
-        }
-      })(),
-    formData: 'FormData' in self,
-    arrayBuffer: 'ArrayBuffer' in self,
-  };
-
-  if (support.arrayBuffer) {
-    var viewClasses = [
-      '[object Int8Array]',
-      '[object Uint8Array]',
-      '[object Uint8ClampedArray]',
-      '[object Int16Array]',
-      '[object Uint16Array]',
-      '[object Int32Array]',
-      '[object Uint32Array]',
-      '[object Float32Array]',
-      '[object Float64Array]',
-    ];
-
-    var isDataView = function(obj) {
-      return obj && DataView.prototype.isPrototypeOf(obj);
-    };
-
-    var isArrayBufferView =
-      ArrayBuffer.isView ||
-      function(obj) {
-        return (
-          obj && viewClasses.indexOf(Object.prototype.toString.call(obj)) > -1
-        );
-      };
-  }
-
-  function normalizeName(name) {
-    if (typeof name !== 'string') {
-      name = String(name);
-    }
-    if (/[^a-z0-9\-#$%&'*+.\^_`|~]/i.test(name)) {
-      throw new TypeError('Invalid character in header field name');
-    }
-    return name.toLowerCase();
-  }
-
-  function normalizeValue(value) {
-    if (typeof value !== 'string') {
-      value = String(value);
-    }
-    return value;
-  }
-
-  // Build a destructive iterator for the value list
-  function iteratorFor(items) {
-    var iterator = {
-      next: function() {
-        var value = items.shift();
-        return {done: value === undefined, value: value};
-      },
-    };
-
-    if (support.iterable) {
-      iterator[Symbol.iterator] = function() {
-        return iterator;
-      };
-    }
-
-    return iterator;
-  }
-
-  function Headers(headers) {
-    this.map = {};
-
-    if (headers instanceof Headers) {
-      headers.forEach(function(value, name) {
-        this.append(name, value);
-      }, this);
-    } else if (Array.isArray(headers)) {
-      headers.forEach(function(header) {
-        this.append(header[0], header[1]);
-      }, this);
-    } else if (headers) {
-      Object.getOwnPropertyNames(headers).forEach(function(name) {
-        this.append(name, headers[name]);
-      }, this);
-    }
-  }
-
-  Headers.prototype.append = function(name, value) {
-    name = normalizeName(name);
-    value = normalizeValue(value);
-    var oldValue = this.map[name];
-    this.map[name] = oldValue ? oldValue + ',' + value : value;
-  };
-
-  Headers.prototype['delete'] = function(name) {
-    delete this.map[normalizeName(name)];
-  };
-
-  Headers.prototype.get = function(name) {
-    name = normalizeName(name);
-    return this.has(name) ? this.map[name] : null;
-  };
-
-  Headers.prototype.has = function(name) {
-    return this.map.hasOwnProperty(normalizeName(name));
-  };
-
-  Headers.prototype.set = function(name, value) {
-    this.map[normalizeName(name)] = normalizeValue(value);
-  };
-
-  Headers.prototype.forEach = function(callback, thisArg) {
-    for (var name in this.map) {
-      if (this.map.hasOwnProperty(name)) {
-        callback.call(thisArg, this.map[name], name, this);
-      }
-    }
-  };
-
-  Headers.prototype.keys = function() {
-    var items = [];
-    this.forEach(function(value, name) {
-      items.push(name);
-    });
-    return iteratorFor(items);
-  };
-
-  Headers.prototype.values = function() {
-    var items = [];
-    this.forEach(function(value) {
-      items.push(value);
-    });
-    return iteratorFor(items);
-  };
-
-  Headers.prototype.entries = function() {
-    var items = [];
-    this.forEach(function(value, name) {
-      items.push([name, value]);
-    });
-    return iteratorFor(items);
-  };
-
-  if (support.iterable) {
-    Headers.prototype[Symbol.iterator] = Headers.prototype.entries;
-  }
-
-  function consumed(body) {
-    if (body.bodyUsed) {
-      return Promise.reject(new TypeError('Already read'));
-    }
-    body.bodyUsed = true;
-  }
-
-  function fileReaderReady(reader) {
-    return new Promise(function(resolve, reject) {
-      reader.onload = function() {
-        resolve(reader.result);
-      };
-      reader.onerror = function() {
-        reject(reader.error);
-      };
-    });
-  }
-
-  function readBlobAsArrayBuffer(blob) {
-    var reader = new FileReader();
-    var promise = fileReaderReady(reader);
-    reader.readAsArrayBuffer(blob);
-    return promise;
-  }
-
-  function readBlobAsText(blob) {
-    var reader = new FileReader();
-    var promise = fileReaderReady(reader);
-    reader.readAsText(blob);
-    return promise;
-  }
-
-  function readArrayBufferAsText(buf) {
-    var view = new Uint8Array(buf);
-    var chars = new Array(view.length);
-
-    for (var i = 0; i < view.length; i++) {
-      chars[i] = String.fromCharCode(view[i]);
-    }
-    return chars.join('');
-  }
-
-  function bufferClone(buf) {
-    if (buf.slice) {
-      return buf.slice(0);
-    } else {
-      var view = new Uint8Array(buf.byteLength);
-      view.set(new Uint8Array(buf));
-      return view.buffer;
-    }
-  }
-
-  function Body() {
-    this.bodyUsed = false;
-
-    this._initBody = function(body) {
-      this._bodyInit = body;
-      if (!body) {
-        this._bodyText = '';
-      } else if (typeof body === 'string') {
-        this._bodyText = body;
-      } else if (support.blob && Blob.prototype.isPrototypeOf(body)) {
-        this._bodyBlob = body;
-      } else if (support.formData && FormData.prototype.isPrototypeOf(body)) {
-        this._bodyFormData = body;
-      } else if (
-        support.searchParams &&
-        URLSearchParams.prototype.isPrototypeOf(body)
-      ) {
-        this._bodyText = body.toString();
-      } else if (support.arrayBuffer && support.blob && isDataView(body)) {
-        this._bodyArrayBuffer = bufferClone(body.buffer);
-        // IE 10-11 can't handle a DataView body.
-        this._bodyInit = new Blob([this._bodyArrayBuffer]);
-      } else if (
-        support.arrayBuffer &&
-        (ArrayBuffer.prototype.isPrototypeOf(body) || isArrayBufferView(body))
-      ) {
-        this._bodyArrayBuffer = bufferClone(body);
-      } else {
-        throw new Error('unsupported BodyInit type');
-      }
-
-      if (!this.headers.get('content-type')) {
-        if (typeof body === 'string') {
-          this.headers.set('content-type', 'text/plain;charset=UTF-8');
-        } else if (this._bodyBlob && this._bodyBlob.type) {
-          this.headers.set('content-type', this._bodyBlob.type);
-        } else if (
-          support.searchParams &&
-          URLSearchParams.prototype.isPrototypeOf(body)
-        ) {
-          this.headers.set(
-            'content-type',
-            'application/x-www-form-urlencoded;charset=UTF-8',
-          );
-        }
-      }
-    };
-
-    if (support.blob) {
-      this.blob = function() {
-        var rejected = consumed(this);
-        if (rejected) {
-          return rejected;
-        }
-
-        if (this._bodyBlob) {
-          return Promise.resolve(this._bodyBlob);
-        } else if (this._bodyArrayBuffer) {
-          return Promise.resolve(new Blob([this._bodyArrayBuffer]));
-        } else if (this._bodyFormData) {
-          throw new Error('could not read FormData body as blob');
-        } else {
-          return Promise.resolve(new Blob([this._bodyText]));
-        }
-      };
-
-      this.arrayBuffer = function() {
-        if (this._bodyArrayBuffer) {
-          return consumed(this) || Promise.resolve(this._bodyArrayBuffer);
-        } else {
-          return this.blob().then(readBlobAsArrayBuffer);
-        }
-      };
-    }
-
-    this.text = function() {
-      var rejected = consumed(this);
-      if (rejected) {
-        return rejected;
-      }
-
-      if (this._bodyBlob) {
-        return readBlobAsText(this._bodyBlob);
-      } else if (this._bodyArrayBuffer) {
-        return Promise.resolve(readArrayBufferAsText(this._bodyArrayBuffer));
-      } else if (this._bodyFormData) {
-        throw new Error('could not read FormData body as text');
-      } else {
-        return Promise.resolve(this._bodyText);
-      }
-    };
-
-    if (support.formData) {
-      this.formData = function() {
-        return this.text().then(decode);
-      };
-    }
-
-    this.json = function() {
-      return this.text().then(JSON.parse);
-    };
-
-    return this;
-  }
-
-  // HTTP methods whose capitalization should be normalized
-  var methods = ['DELETE', 'GET', 'HEAD', 'OPTIONS', 'POST', 'PUT'];
-
-  function normalizeMethod(method) {
-    var upcased = method.toUpperCase();
-    return methods.indexOf(upcased) > -1 ? upcased : method;
-  }
-
-  function Request(input, options) {
-    options = options || {};
-    var body = options.body;
-
-    if (input instanceof Request) {
-      if (input.bodyUsed) {
-        throw new TypeError('Already read');
-      }
-      this.url = input.url;
-      this.credentials = input.credentials;
-      if (!options.headers) {
-        this.headers = new Headers(input.headers);
-      }
-      this.method = input.method;
-      this.mode = input.mode;
-      if (!body && input._bodyInit != null) {
-        body = input._bodyInit;
-        input.bodyUsed = true;
-      }
-    } else {
-      this.url = String(input);
-    }
-
-    this.credentials = options.credentials || this.credentials || 'omit';
-    if (options.headers || !this.headers) {
-      this.headers = new Headers(options.headers);
-    }
-    this.method = normalizeMethod(options.method || this.method || 'GET');
-    this.mode = options.mode || this.mode || null;
-    this.referrer = null;
-
-    if ((this.method === 'GET' || this.method === 'HEAD') && body) {
-      throw new TypeError('Body not allowed for GET or HEAD requests');
-    }
-    this._initBody(body);
-  }
-
-  Request.prototype.clone = function() {
-    return new Request(this, {body: this._bodyInit});
-  };
-
-  function decode(body) {
-    var form = new FormData();
-    body
-      .trim()
-      .split('&')
-      .forEach(function(bytes) {
-        if (bytes) {
-          var split = bytes.split('=');
-          var name = split.shift().replace(/\+/g, ' ');
-          var value = split.join('=').replace(/\+/g, ' ');
-          form.append(decodeURIComponent(name), decodeURIComponent(value));
-        }
-      });
-    return form;
-  }
-
-  function parseHeaders(rawHeaders) {
-    var headers = new Headers();
-    // Replace instances of \r\n and \n followed by at least one space or horizontal tab with a space
-    // https://tools.ietf.org/html/rfc7230#section-3.2
-    var preProcessedHeaders = rawHeaders.replace(/\r?\n[\t ]+/g, ' ');
-    preProcessedHeaders.split(/\r?\n/).forEach(function(line) {
-      var parts = line.split(':');
-      var key = parts.shift().trim();
-      if (key) {
-        var value = parts.join(':').trim();
-        headers.append(key, value);
-      }
-    });
-    return headers;
-  }
-
-  Body.call(Request.prototype);
-
-  function Response(bodyInit, options) {
-    if (!options) {
-      options = {};
-    }
-
-    this.type = 'default';
-    this.status = options.status === undefined ? 200 : options.status;
-    this.ok = this.status >= 200 && this.status < 300;
-    this.statusText = 'statusText' in options ? options.statusText : 'OK';
-    this.headers = new Headers(options.headers);
-    this.url = options.url || '';
-    this._initBody(bodyInit);
-  }
-
-  Body.call(Response.prototype);
-
-  Response.prototype.clone = function() {
-    return new Response(this._bodyInit, {
-      status: this.status,
-      statusText: this.statusText,
-      headers: new Headers(this.headers),
-      url: this.url,
-    });
-  };
-
-  Response.error = function() {
-    var response = new Response(null, {status: 0, statusText: ''});
-    response.type = 'error';
-    return response;
-  };
-
-  var redirectStatuses = [301, 302, 303, 307, 308];
-
-  Response.redirect = function(url, status) {
-    if (redirectStatuses.indexOf(status) === -1) {
-      throw new RangeError('Invalid status code');
-    }
-
-    return new Response(null, {status: status, headers: {location: url}});
-  };
-
-  self.Headers = Headers;
-  self.Request = Request;
-  self.Response = Response;
-
-  self.fetch = function(input, init) {
-    return new Promise(function(resolve, reject) {
-      var request = new Request(input, init);
-      var xhr = new XMLHttpRequest();
-
-      xhr.onload = function() {
-        var options = {
-          status: xhr.status,
-          statusText: xhr.statusText,
-          headers: parseHeaders(xhr.getAllResponseHeaders() || ''),
-        };
-        options.url =
-          'responseURL' in xhr
-            ? xhr.responseURL
-            : options.headers.get('X-Request-URL');
-        var body = 'response' in xhr ? xhr.response : xhr.responseText;
-        resolve(new Response(body, options));
-      };
-
-      xhr.onerror = function() {
-        reject(new TypeError('Network request failed'));
-      };
-
-      xhr.ontimeout = function() {
-        reject(new TypeError('Network request failed'));
-      };
-
-      xhr.open(request.method, request.url, true);
-
-      if (request.credentials === 'include') {
-        xhr.withCredentials = true;
-      } else if (request.credentials === 'omit') {
-        xhr.withCredentials = false;
-      }
-
-      if ('responseType' in xhr && support.blob) {
-        xhr.responseType = 'blob';
-      }
-
-      request.headers.forEach(function(value, name) {
-        xhr.setRequestHeader(name, value);
-      });
-
-      xhr.send(
-        typeof request._bodyInit === 'undefined' ? null : request._bodyInit,
-      );
-    });
-  };
-  self.fetch.polyfill = true;
-})(typeof self !== 'undefined' ? self : this);

RNTester/android/app/build.gradle

@@ -68,7 +68,10 @@ project.ext.react = [
     bundleAssetName: "RNTesterApp.android.bundle",
     entryFile: file("../../js/RNTesterApp.android.js"),
     root: "$rootDir",
-    inputExcludes: ["android/**", "./**", ".gradle/**"]
+    inputExcludes: ["android/**", "./**", ".gradle/**"],
+    composeSourceMapsPath: "$rootDir/scripts/compose-source-maps.js",
+    hermesCommand: "../../../node_modules/hermesvm/%OS-BIN%/hermes",
+    enableHermesForVariant: { def v -> v.name.contains("hermes") }
 ]
 
 apply from: "../../../react.gradle"
@@ -105,6 +108,16 @@ android {
         targetCompatibility JavaVersion.VERSION_1_8
     }
 
+    flavorDimensions "vm"
+    productFlavors {
+      hermes {
+        dimension "vm"
+      }
+      jsc {
+        dimension "vm"
+      }
+    }
+
     defaultConfig {
         applicationId "com.facebook.react.uiapp"
         minSdkVersion 16
@@ -138,6 +151,12 @@ android {
             signingConfig signingConfigs.release
         }
     }
+    packagingOptions {
+        pickFirst '**/armeabi-v7a/libc++_shared.so'
+        pickFirst '**/x86/libc++_shared.so'
+        pickFirst '**/arm64-v8a/libc++_shared.so'
+        pickFirst '**/x86_64/libc++_shared.so'
+    }
 }
 
 dependencies {
@@ -146,6 +165,10 @@ dependencies {
     // Build React Native from source
     implementation project(':ReactAndroid')
 
+    def hermesPath = '$projectDir/../../../../node_modules/hermesvm/android/'
+    debugImplementation files(hermesPath + "hermes-debug.aar")
+    releaseImplementation files(hermesPath + "hermes-release.aar")
+
     if (useIntlJsc) {
         implementation 'org.webkit:android-jsc-intl:+'
     } else {

RNTester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterApplication.java

@@ -14,8 +14,11 @@ import com.facebook.react.BuildConfig;
 import com.facebook.react.ReactApplication;
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
+import com.facebook.react.bridge.JavaScriptExecutorFactory;
+import com.facebook.hermes.reactexecutor.HermesExecutorFactory;
 import com.facebook.react.shell.MainReactPackage;
 import com.facebook.react.views.text.ReactFontManager;
+import com.facebook.soloader.SoLoader;
 
 import java.util.Arrays;
 import java.util.List;
@@ -47,8 +50,9 @@ public class RNTesterApplication extends Application implements ReactApplication
 
   @Override
   public void onCreate() {
-    ReactFontManager.getInstance().addCustomFont(this, "Srisakdi", R.font.srisakdi);
+    ReactFontManager.getInstance().addCustomFont(this, "Rubik", R.font.rubik);
     super.onCreate();
+    SoLoader.init(this, /* native exopackage */ false);
   }
 
   @Override

RNTester/android/app/src/main/res/font/rubik.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<font-family xmlns:app="http://schemas.android.com/apk/res-auto">
+  <font app:fontStyle="normal" app:fontWeight="300" app:font="@font/rubik_light"/>
+  <font app:fontStyle="normal" app:fontWeight="400" app:font="@font/rubik_regular"/>
+  <font app:fontStyle="normal" app:fontWeight="500" app:font="@font/rubik_medium" />
+  <font app:fontStyle="normal" app:fontWeight="700" app:font="@font/rubik_bold" />
+  <font app:fontStyle="italic" app:fontWeight="500" app:font="@font/rubik_medium_italic" />
+</font-family>

RNTester/android/app/src/main/res/font/srisakdi.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<font-family xmlns:app="http://schemas.android.com/apk/res-auto">
-  <font app:fontStyle="normal" app:fontWeight="400" app:font="@font/srisakdi_regular"/>
-  <font app:fontStyle="normal" app:fontWeight="700" app:font="@font/srisakdi_bold" />
-</font-family>

RNTester/js/TextExample.android.js

@@ -183,13 +183,41 @@ class TextExample extends React.Component<{}> {
               <Text style={{fontFamily: 'notoserif', fontStyle: 'italic'}}>
                 NotoSerif Italic (Missing Font file)
               </Text>
-              <Text style={{fontFamily: 'Srisakdi'}}>Srisakdi Regular</Text>
               <Text
                 style={{
-                  fontFamily: 'Srisakdi',
-                  fontWeight: 'bold',
+                  fontFamily: 'Rubik',
+                  fontWeight: 'normal',
                 }}>
-                Srisakdi Bold
+                Rubik Regular
+              </Text>
+              <Text
+                style={{
+                  fontFamily: 'Rubik',
+                  fontWeight: '300',
+                }}>
+                Rubik Light
+              </Text>
+              <Text
+                style={{
+                  fontFamily: 'Rubik',
+                  fontWeight: '700',
+                }}>
+                Rubik Bold
+              </Text>
+              <Text
+                style={{
+                  fontFamily: 'Rubik',
+                  fontWeight: '500',
+                }}>
+                Rubik Medium
+              </Text>
+              <Text
+                style={{
+                  fontFamily: 'Rubik',
+                  fontStyle: 'italic',
+                  fontWeight: '500',
+                }}>
+                Rubik Medium Italic
               </Text>
             </View>
           </View>
@@ -205,15 +233,15 @@ class TextExample extends React.Component<{}> {
         </RNTesterBlock>
         <RNTesterBlock title="Font Weight">
           <Text style={{fontWeight: 'bold'}}>Move fast and be bold</Text>
-          <Text style={{fontWeight: 'normal'}}>Move fast and be bold</Text>
+          <Text style={{fontWeight: 'normal'}}>Move fast and be normal</Text>
         </RNTesterBlock>
         <RNTesterBlock title="Font Style">
-          <Text style={{fontStyle: 'italic'}}>Move fast and be bold</Text>
-          <Text style={{fontStyle: 'normal'}}>Move fast and be bold</Text>
+          <Text style={{fontStyle: 'italic'}}>Move fast and be italic</Text>
+          <Text style={{fontStyle: 'normal'}}>Move fast and be normal</Text>
         </RNTesterBlock>
         <RNTesterBlock title="Font Style and Weight">
           <Text style={{fontStyle: 'italic', fontWeight: 'bold'}}>
-            Move fast and be bold
+            Move fast and be both bold and italic
           </Text>
         </RNTesterBlock>
         <RNTesterBlock title="Text Decoration">

RNTester/js/TextExample.ios.js

@@ -453,6 +453,23 @@ class TextWithCapBaseBox extends React.Component<*, *> {
   }
 }
 
+function LongTextExample() {
+  const [collapsed, setCollapsed] = React.useState(true);
+  return (
+    <View>
+      <Button
+        onPress={() => setCollapsed(state => !state)}
+        title="Toggle long text"
+      />
+      <Text>
+        {Array.from({length: collapsed ? 5 : 5000})
+          .map((_, i) => i)
+          .join('\n')}
+      </Text>
+    </View>
+  );
+}
+
 exports.title = '<Text>';
 exports.description = 'Base component for rendering styled text.';
 exports.displayName = 'TextExample';
@@ -1125,4 +1142,10 @@ exports.examples = [
       );
     },
   },
+  {
+    title: 'Async rendering for long text',
+    render: function() {
+      return <LongTextExample />;
+    },
+  },
 ];

React/Base/RCTModuleMethod.mm

@@ -91,6 +91,7 @@ static BOOL RCTParseSelectorPart(const char **input, NSMutableString *selector)
 static BOOL RCTParseUnused(const char **input)
 {
   return RCTReadString(input, "__attribute__((unused))") ||
+         RCTReadString(input, "__attribute__((__unused__))") ||
          RCTReadString(input, "__unused");
 }
 

React/Base/RCTVersion.m

@@ -21,8 +21,8 @@ static void __makeVersion()
 {
   __rnVersion = @{
                   RCTVersionMajor: @(0),
-                  RCTVersionMinor: @(0),
-                  RCTVersionPatch: @(0),
+                  RCTVersionMinor: @(60),
+                  RCTVersionPatch: @(2),
                   RCTVersionPrerelease: [NSNull null],
                   };
 }

React/Views/RCTModalHostView.m

@@ -129,8 +129,6 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:coder)
     [subview addGestureRecognizer:_menuButtonGestureRecognizer];
   }
 #endif
-  subview.autoresizingMask = UIViewAutoresizingFlexibleHeight |
-                             UIViewAutoresizingFlexibleWidth;
 
   [_modalViewController.view insertSubview:subview atIndex:0];
   _reactSubview = subview;

React/Views/UIView+React.m

@@ -297,12 +297,12 @@
   return self;
 }
 
-- (NSArray<NSString *> *)accessibilityActions
+- (NSArray<NSDictionary *> *)accessibilityActions
 {
   return objc_getAssociatedObject(self, _cmd);
 }
 
-- (void)setAccessibilityActions:(NSArray<NSString *> *)accessibilityActions
+- (void)setAccessibilityActions:(NSArray<NSDictionary *> *)accessibilityActions
 {
   objc_setAssociatedObject(self, @selector(accessibilityActions), accessibilityActions, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
 }

ReactAndroid/build.gradle

@@ -88,6 +88,17 @@ task prepareFolly(dependsOn: dependenciesPath ? [] : [downloadFolly], type: Copy
     into("$thirdPartyNdkDir/folly")
 }
 
+task prepareHermes() {
+    def hermesAAR = new File("$projectDir/../node_modules/hermesvm/android/hermes-debug.aar")
+    def soFiles = zipTree(hermesAAR).matching({ it.include "**/*.so" })
+
+    copy {
+        from soFiles
+        from "src/main/jni/first-party/hermes/Android.mk"
+        into "$thirdPartyNdkDir/hermes"
+    }
+}
+
 task downloadGlog(dependsOn: createNativeDepsDirectories, type: Download) {
     src("https://github.com/google/glog/archive/v${GLOG_VERSION}.tar.gz")
     onlyIfNewer(true)
@@ -193,13 +204,23 @@ def findNdkBuildFullPath() {
     def ndkDir = android.hasProperty("plugin") ? android.plugin.ndkFolder :
             plugins.getPlugin("com.android.library").hasProperty("sdkHandler") ?
                     plugins.getPlugin("com.android.library").sdkHandler.getNdkFolder() :
-                    android.ndkDirectory.absolutePath
+                    android.ndkDirectory ? android.ndkDirectory.absolutePath : null
     if (ndkDir) {
         return new File(ndkDir, getNdkBuildName()).getAbsolutePath()
     }
     return null
 }
 
+def reactNativeDevServerPort() {
+    def value = project.getProperties().get("reactNativeDevServerPort")
+    return value != null ? value : "8081"
+}
+
+def reactNativeInspectorProxyPort() {
+    def value = project.getProperties().get("reactNativeInspectorProxyPort")
+    return value != null ? value : reactNativeDevServerPort()
+}
+
 def getNdkBuildFullPath() {
     def ndkBuildFullPath = findNdkBuildFullPath()
     if (ndkBuildFullPath == null) {
@@ -219,7 +240,7 @@ def getNdkBuildFullPath() {
     return ndkBuildFullPath
 }
 
-task buildReactNdkLib(dependsOn: [prepareJSC, prepareBoost, prepareDoubleConversion, prepareFolly, prepareGlog], type: Exec) {
+task buildReactNdkLib(dependsOn: [prepareJSC, prepareHermes, prepareBoost, prepareDoubleConversion, prepareFolly, prepareGlog], type: Exec) {
     inputs.dir("$projectDir/../ReactCommon")
     inputs.dir("src/main/jni")
     outputs.dir("$buildDir/react-ndk/all")
@@ -255,6 +276,7 @@ task packageReactNdkLibs(dependsOn: buildReactNdkLib, type: Copy) {
     from("$buildDir/react-ndk/all")
     into("$buildDir/react-ndk/exported")
     exclude("**/libjsc.so")
+    exclude("**/libhermes.so")
 }
 
 task packageReactNdkLibsForBuck(dependsOn: packageReactNdkLibs, type: Copy) {
@@ -284,6 +306,10 @@ android {
 
         buildConfigField("boolean", "IS_INTERNAL_BUILD", "false")
         buildConfigField("int", "EXOPACKAGE_FLAGS", "0")
+
+        resValue "integer", "react_native_dev_server_port", reactNativeDevServerPort()
+        resValue "integer", "react_native_inspector_proxy_port", reactNativeInspectorProxyPort()
+
         testApplicationId("com.facebook.react.tests.gradle")
         testInstrumentationRunner("androidx.test.runner.AndroidJUnitRunner")
     }

ReactAndroid/gradle.properties

@@ -1,4 +1,4 @@
-VERSION_NAME=1000.0.0-master
+VERSION_NAME=0.60.2
 GROUP=com.facebook.react
 
 POM_NAME=ReactNative
@@ -12,7 +12,7 @@ JUNIT_VERSION=4.12
 FEST_ASSERT_CORE_VERSION=2.0M10
 
 ANDROID_SUPPORT_TEST_VERSION=1.0.2
-FRESCO_VERSION=1.13.0
+FRESCO_VERSION=2.0.0
 OKHTTP_VERSION=3.12.1
 SO_LOADER_VERSION=0.6.0
 

ReactAndroid/src/androidTest/java/com/facebook/react/testing/ReactAppTestActivity.java

@@ -213,6 +213,14 @@ public class ReactAppTestActivity extends FragmentActivity
     } else {
       builder.addPackage(new MainReactPackage());
     }
+    /**
+     *  The {@link ReactContext#mCurrentActivity} never to be set if initial lifecycle state is resumed.
+     *  So we should call {@link ReactInstanceManagerBuilder#setCurrentActivity}.
+     *
+     *  Finally,{@link ReactInstanceManagerBuilder#build()} will create instance of {@link ReactInstanceManager}.
+     *  And also will set {@link ReactContext#mCurrentActivity}.
+     */
+    builder.setCurrentActivity(this);
     builder
         .addPackage(new InstanceSpecForTestPackage(spec))
         // By not setting a JS module name, we force the bundle to be always loaded from

ReactAndroid/src/main/java/com/facebook/hermes/instrumentation/HermesMemoryDumper.h

@@ -0,0 +1,48 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <fb/fbjni.h>
+#include <string>
+
+namespace facebook {
+namespace jsi {
+namespace jni {
+
+namespace jni = ::facebook::jni;
+
+class HermesMemoryDumper : public jni::JavaClass<HermesMemoryDumper> {
+ public:
+  constexpr static auto kJavaDescriptor =
+      "Lcom/facebook/hermes/instrumentation/HermesMemoryDumper;";
+
+  bool shouldSaveSnapshot() {
+    static auto shouldSaveSnapshotMethod =
+        javaClassStatic()->getMethod<jboolean()>("shouldSaveSnapshot");
+    return shouldSaveSnapshotMethod(self());
+  }
+
+  std::string getInternalStorage() {
+    static auto getInternalStorageMethod =
+        javaClassStatic()->getMethod<jstring()>("getInternalStorage");
+    return getInternalStorageMethod(self())->toStdString();
+  }
+
+  std::string getId() {
+    static auto getInternalStorageMethod =
+        javaClassStatic()->getMethod<jstring()>("getId");
+    return getInternalStorageMethod(self())->toStdString();
+  }
+
+  void setMetaData(std::string crashId) {
+    static auto getIdMethod =
+        javaClassStatic()->getMethod<void(std::string)>("setMetaData");
+    getIdMethod(self(), crashId);
+  }
+};
+
+} // namespace jni
+} // namespace jsi
+} // namespace facebook

ReactAndroid/src/main/java/com/facebook/hermes/instrumentation/HermesMemoryDumper.java

@@ -0,0 +1,14 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+package com.facebook.hermes.instrumentation;
+
+public interface HermesMemoryDumper {
+  boolean shouldSaveSnapshot();
+  String getInternalStorage();
+  String getId();
+  void setMetaData(String crashId);
+}

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/Android.mk

@@ -0,0 +1,40 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+REACT_NATIVE := $(LOCAL_PATH)/../../../../../../../..
+
+LOCAL_MODULE := hermes-executor-release
+
+LOCAL_SRC_FILES := $(wildcard $(LOCAL_PATH)/*.cpp)
+
+LOCAL_C_INCLUDES := $(LOCAL_PATH) $(REACT_NATIVE)/ReactCommon/jsi $(REACT_NATIVE)/node_modules/hermesvm/android/include
+
+LOCAL_CPP_FEATURES := exceptions
+
+LOCAL_STATIC_LIBRARIES := libjsireact libjsi
+LOCAL_SHARED_LIBRARIES := libfolly_json libfb libreactnativejni libhermes
+
+include $(BUILD_SHARED_LIBRARY)
+
+
+include $(CLEAR_VARS)
+REACT_NATIVE := $(LOCAL_PATH)/../../../../../../../..
+
+LOCAL_MODULE := hermes-executor-debug
+LOCAL_CFLAGS := -DHERMES_ENABLE_DEBUGGER=1
+
+LOCAL_SRC_FILES := $(wildcard $(LOCAL_PATH)/*.cpp)
+
+LOCAL_C_INCLUDES := $(LOCAL_PATH) $(REACT_NATIVE)/ReactCommon/jsi $(REACT_NATIVE)/node_modules/hermesvm/android/include
+
+LOCAL_CPP_FEATURES := exceptions
+
+LOCAL_STATIC_LIBRARIES := libjsireact libjsi libhermes-inspector
+LOCAL_SHARED_LIBRARIES := libfolly_json libfb libreactnativejni libhermes
+
+include $(BUILD_SHARED_LIBRARY)

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/HermesExecutor.java

@@ -0,0 +1,68 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+package com.facebook.hermes.reactexecutor;
+
+import com.facebook.hermes.instrumentation.HermesMemoryDumper;
+import com.facebook.jni.HybridData;
+import com.facebook.react.bridge.JavaScriptExecutor;
+import com.facebook.soloader.SoLoader;
+import java.util.concurrent.ScheduledExecutorService;
+import javax.annotation.Nullable;
+
+public class HermesExecutor extends JavaScriptExecutor {
+  private static String mode_;
+  static {
+    // libhermes must be loaded explicitly to invoke its JNI_OnLoad.
+    SoLoader.loadLibrary("hermes");
+    try {
+      SoLoader.loadLibrary("hermes-executor-release");
+      mode_ = "Release";
+    } catch(UnsatisfiedLinkError e) {
+      SoLoader.loadLibrary("hermes-executor-debug");
+      mode_ = "Debug";
+    }
+  }
+
+  HermesExecutor(@Nullable RuntimeConfig config) {
+    super(
+        config == null
+            ? initHybridDefaultConfig()
+            : initHybrid(
+                config.heapSizeMB,
+                config.es6Symbol,
+                config.bytecodeWarmupPercent,
+                config.tripWireEnabled,
+                config.heapDumper,
+                config.tripWireCooldownMS,
+                config.tripWireLimitBytes));
+  }
+
+  @Override
+  public String getName() {
+    return "HermesExecutor" + mode_;
+  }
+
+  /**
+   * Return whether this class can load a file at the given path, based on a binary compatibility
+   * check between the contents of the file and the Hermes VM.
+   *
+   * @param path the path containing the file to inspect.
+   * @return whether the given file is compatible with the Hermes VM.
+   */
+  public static native boolean canLoadFile(String path);
+
+  private static native HybridData initHybridDefaultConfig();
+
+  private static native HybridData initHybrid(
+      long heapSizeMB,
+      boolean es6Symbol,
+      int bytecodeWarmupPercent,
+      boolean tripWireEnabled,
+      @Nullable HermesMemoryDumper heapDumper,
+      long tripWireCooldownMS,
+      long tripWireLimitBytes);
+}

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/HermesExecutorFactory.cpp

@@ -0,0 +1,230 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include "HermesExecutorFactory.h"
+
+#include <thread>
+
+#include <cxxreact/MessageQueueThread.h>
+#include <cxxreact/SystraceSection.h>
+#include <hermes/hermes_tracing.h>
+#include <jsi/decorator.h>
+
+#ifdef HERMES_ENABLE_DEBUGGER
+#include <hermes/inspector/RuntimeAdapter.h>
+#include <hermes/inspector/chrome/Registration.h>
+#endif
+
+#include "JSITracing.h"
+
+using namespace facebook::hermes;
+using namespace facebook::jsi;
+
+namespace facebook {
+namespace react {
+
+namespace {
+
+std::unique_ptr<HermesRuntime> makeHermesRuntimeSystraced(
+    const ::hermes::vm::RuntimeConfig &runtimeConfig) {
+  SystraceSection s("HermesExecutorFactory::makeHermesRuntimeSystraced");
+  return hermes::makeHermesRuntime(runtimeConfig);
+}
+
+#ifdef HERMES_ENABLE_DEBUGGER
+
+class HermesExecutorRuntimeAdapter
+    : public facebook::hermes::inspector::RuntimeAdapter {
+ public:
+  HermesExecutorRuntimeAdapter(
+      std::shared_ptr<Runtime> runtime,
+      HermesRuntime &hermesRuntime,
+      std::shared_ptr<MessageQueueThread> thread)
+      : runtime_(runtime),
+        hermesRuntime_(hermesRuntime),
+        thread_(std::move(thread)) {}
+
+  virtual ~HermesExecutorRuntimeAdapter() = default;
+
+  HermesRuntime &getRuntime() override {
+    return hermesRuntime_;
+  }
+
+  void tickleJs() override {
+    // The queue will ensure that runtime_ is still valid when this
+    // gets invoked.
+    // clang-format off
+    thread_->runOnQueue([&runtime = hermesRuntime_]() {
+      // clang-format on
+      auto func = runtime.global().getPropertyAsFunction(runtime, "__tickleJs");
+      func.call(runtime);
+    });
+  }
+
+ private:
+  std::shared_ptr<Runtime> runtime_;
+  HermesRuntime &hermesRuntime_;
+
+  std::shared_ptr<MessageQueueThread> thread_;
+};
+
+#endif
+
+struct ReentrancyCheck {
+// This is effectively a very subtle and complex assert, so only
+// include it in builds which would include asserts.
+#ifndef NDEBUG
+  ReentrancyCheck() : tid(std::thread::id()), depth(0) {}
+
+  void before() {
+    std::thread::id this_id = std::this_thread::get_id();
+    std::thread::id expected = std::thread::id();
+
+    // A note on memory ordering: the main purpose of these checks is
+    // to observe a before/before race, without an intervening after.
+    // This will be detected by the compare_exchange_strong atomicity
+    // properties, regardless of memory order.
+    //
+    // For everything else, it is easiest to think of 'depth' as a
+    // proxy for any access made inside the VM.  If access to depth
+    // are reordered incorrectly, the same could be true of any other
+    // operation made by the VM.  In fact, using acquire/release
+    // memory ordering could create barriers which mask a programmer
+    // error.  So, we use relaxed memory order, to avoid masking
+    // actual ordering errors.  Although, in practice, ordering errors
+    // of this sort would be surprising, because the decorator would
+    // need to call after() without before().
+
+    if (tid.compare_exchange_strong(
+            expected, this_id, std::memory_order_relaxed)) {
+      // Returns true if tid and expected were the same.  If they
+      // were, then the stored tid referred to no thread, and we
+      // atomically saved this thread's tid.  Now increment depth.
+      assert(depth == 0 && "No thread id, but depth != 0");
+      ++depth;
+    } else if (expected == this_id) {
+      // If the stored tid referred to a thread, expected was set to
+      // that value.  If that value is this thread's tid, that's ok,
+      // just increment depth again.
+      assert(depth != 0 && "Thread id was set, but depth == 0");
+      ++depth;
+    } else {
+      // The stored tid was some other thread.  This indicates a bad
+      // programmer error, where VM methods were called on two
+      // different threads unsafely.  Fail fast (and hard) so the
+      // crash can be analyzed.
+      __builtin_trap();
+    }
+  }
+
+  void after() {
+    assert(
+        tid.load(std::memory_order_relaxed) == std::this_thread::get_id() &&
+        "No thread id in after()");
+    if (--depth == 0) {
+      // If we decremented depth to zero, store no-thread into tid.
+      std::thread::id expected = std::this_thread::get_id();
+      bool didWrite = tid.compare_exchange_strong(
+          expected, std::thread::id(), std::memory_order_relaxed);
+      assert(didWrite && "Decremented to zero, but no tid write");
+    }
+  }
+
+  std::atomic<std::thread::id> tid;
+  // This is not atomic, as it is only written or read from the owning
+  // thread.
+  unsigned int depth;
+#endif
+};
+
+// This adds ReentrancyCheck and debugger enable/teardown to the given
+// Runtime.
+class DecoratedRuntime : public jsi::WithRuntimeDecorator<ReentrancyCheck> {
+ public:
+  // The first argument may be a tracing runtime which itself
+  // decorates the real HermesRuntime, depending on the build config.
+  // The second argument is the the real HermesRuntime as well to
+  // manage the debugger registration.
+  DecoratedRuntime(
+      std::unique_ptr<Runtime> runtime,
+      HermesRuntime &hermesRuntime,
+      std::shared_ptr<MessageQueueThread> jsQueue)
+      : jsi::WithRuntimeDecorator<ReentrancyCheck>(*runtime, reentrancyCheck_),
+        runtime_(std::move(runtime)),
+        hermesRuntime_(hermesRuntime) {
+#ifdef HERMES_ENABLE_DEBUGGER
+    auto adapter = std::make_unique<HermesExecutorRuntimeAdapter>(
+        runtime_, hermesRuntime_, jsQueue);
+    facebook::hermes::inspector::chrome::enableDebugging(
+        std::move(adapter), "Hermes React Native");
+#else
+    (void)hermesRuntime_;
+#endif
+  }
+
+  ~DecoratedRuntime() {
+#ifdef HERMES_ENABLE_DEBUGGER
+    facebook::hermes::inspector::chrome::disableDebugging(hermesRuntime_);
+#endif
+  }
+
+ private:
+  // runtime_ is a TracingRuntime, but we don't need to worry about
+  // the details.  hermesRuntime is a reference to the HermesRuntime
+  // managed by the TracingRuntime.
+  //
+  // HermesExecutorRuntimeAdapter requirements are kept, because the
+  // dtor will disable debugging on the HermesRuntime before the
+  // member managing it is destroyed.
+
+  std::shared_ptr<Runtime> runtime_;
+  ReentrancyCheck reentrancyCheck_;
+  HermesRuntime &hermesRuntime_;
+};
+
+} // namespace
+
+std::unique_ptr<JSExecutor> HermesExecutorFactory::createJSExecutor(
+    std::shared_ptr<ExecutorDelegate> delegate,
+    std::shared_ptr<MessageQueueThread> jsQueue) {
+  std::unique_ptr<HermesRuntime> hermesRuntime =
+      makeHermesRuntimeSystraced(runtimeConfig_);
+  HermesRuntime& hermesRuntimeRef = *hermesRuntime;
+  auto decoratedRuntime = std::make_shared<DecoratedRuntime>(
+      makeTracingHermesRuntime(std::move(hermesRuntime), runtimeConfig_),
+      hermesRuntimeRef,
+      jsQueue);
+
+  // So what do we have now?
+  // DecoratedRuntime -> TracingRuntime -> HermesRuntime
+  //
+  // DecoratedRuntime is held by JSIExecutor.  When it gets used, it
+  // will check that it's on the right thread, do any necessary trace
+  // logging, then call the real HermesRuntime.  When it is destroyed,
+  // it will shut down the debugger before the HermesRuntime is.  In
+  // the normal case where tracing and debugging are not compiled in,
+  // all that's left is the thread checking.
+
+  // Add js engine information to Error.prototype so in error reporting we
+  // can send this information.
+  auto errorPrototype =
+      decoratedRuntime->global()
+          .getPropertyAsObject(*decoratedRuntime, "Error")
+          .getPropertyAsObject(*decoratedRuntime, "prototype");
+  errorPrototype.setProperty(*decoratedRuntime, "jsEngine", "hermes");
+
+  return std::make_unique<HermesExecutor>(
+      decoratedRuntime, delegate, jsQueue, timeoutInvoker_, runtimeInstaller_);
+}
+
+HermesExecutor::HermesExecutor(
+    std::shared_ptr<jsi::Runtime> runtime,
+    std::shared_ptr<ExecutorDelegate> delegate,
+    std::shared_ptr<MessageQueueThread> jsQueue,
+    const JSIScopedTimeoutInvoker &timeoutInvoker,
+    RuntimeInstaller runtimeInstaller)
+    : JSIExecutor(runtime, delegate, timeoutInvoker, runtimeInstaller) {
+  jsi::addNativeTracingHooks(*runtime);
+}
+
+} // namespace react
+} // namespace facebook

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/HermesExecutorFactory.h

@@ -0,0 +1,50 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <hermes/hermes.h>
+#include <jsireact/JSIExecutor.h>
+#include <functional>
+#include <utility>
+
+namespace facebook {
+namespace react {
+
+class HermesExecutorFactory : public JSExecutorFactory {
+ public:
+  explicit HermesExecutorFactory(
+      JSIExecutor::RuntimeInstaller runtimeInstaller,
+      const JSIScopedTimeoutInvoker& timeoutInvoker =
+          JSIExecutor::defaultTimeoutInvoker,
+      ::hermes::vm::RuntimeConfig runtimeConfig = ::hermes::vm::RuntimeConfig())
+      : runtimeInstaller_(runtimeInstaller),
+        timeoutInvoker_(timeoutInvoker),
+        runtimeConfig_(std::move(runtimeConfig)) {
+    assert(timeoutInvoker_ && "Should not have empty timeoutInvoker");
+  }
+
+  std::unique_ptr<JSExecutor> createJSExecutor(
+      std::shared_ptr<ExecutorDelegate> delegate,
+      std::shared_ptr<MessageQueueThread> jsQueue) override;
+
+ private:
+  JSIExecutor::RuntimeInstaller runtimeInstaller_;
+  JSIScopedTimeoutInvoker timeoutInvoker_;
+  ::hermes::vm::RuntimeConfig runtimeConfig_;
+};
+
+class HermesExecutor : public JSIExecutor {
+ public:
+  HermesExecutor(
+      std::shared_ptr<jsi::Runtime> runtime,
+      std::shared_ptr<ExecutorDelegate> delegate,
+      std::shared_ptr<MessageQueueThread> jsQueue,
+      const JSIScopedTimeoutInvoker& timeoutInvoker,
+      RuntimeInstaller runtimeInstaller);
+
+ private:
+  JSIScopedTimeoutInvoker timeoutInvoker_;
+};
+
+} // namespace react
+} // namespace facebook

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/HermesExecutorFactory.java

@@ -0,0 +1,34 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+package com.facebook.hermes.reactexecutor;
+
+import com.facebook.react.bridge.JavaScriptExecutor;
+import com.facebook.react.bridge.JavaScriptExecutorFactory;
+
+public class HermesExecutorFactory implements JavaScriptExecutorFactory {
+  private static final String TAG = "Hermes";
+
+  private final RuntimeConfig mConfig;
+
+  public HermesExecutorFactory() {
+    this(null);
+  }
+
+  public HermesExecutorFactory(RuntimeConfig config) {
+    mConfig = config;
+  }
+
+  @Override
+  public JavaScriptExecutor create() {
+    return new HermesExecutor(mConfig);
+  }
+
+  @Override
+  public String toString() {
+    return "JSIExecutor+HermesRuntime";
+  }
+}

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/JSITracing.cpp

@@ -0,0 +1,15 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include "JSITracing.h"
+
+namespace facebook {
+namespace jsi {
+void addNativeTracingHooks(Runtime &rt) {
+  assert(false && "unimplemented");
+}
+} // namespace jsi
+} // namespace facebook

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/JSITracing.h

@@ -0,0 +1,15 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <jsi/jsi.h>
+
+namespace facebook {
+namespace jsi {
+
+void addNativeTracingHooks(Runtime &rt);
+
+} // namespace jsi
+} // namespace facebook

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/OnLoad.cpp

@@ -0,0 +1,154 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <../instrumentation/HermesMemoryDumper.h>
+#include <HermesExecutorFactory.h>
+#include <fb/fbjni.h>
+#include <folly/Memory.h>
+#include <hermes/Public/GCConfig.h>
+#include <hermes/Public/RuntimeConfig.h>
+#include <jni.h>
+#include <react/jni/JReactMarker.h>
+#include <react/jni/JSLogging.h>
+#include <react/jni/JavaScriptExecutorHolder.h>
+
+namespace facebook {
+namespace react {
+
+/// Converts a duration given as a long from Java, into a std::chrono duration.
+static constexpr std::chrono::hours msToHours(jlong ms) {
+  using namespace std::chrono;
+  return duration_cast<hours>(milliseconds(ms));
+}
+
+static ::hermes::vm::RuntimeConfig makeRuntimeConfig(
+    jlong heapSizeMB,
+    bool es6Symbol,
+    jint bytecodeWarmupPercent,
+    bool tripWireEnabled,
+    jni::alias_ref<jsi::jni::HermesMemoryDumper> heapDumper,
+    jlong tripWireCooldownMS,
+    jlong tripWireLimitBytes) {
+  namespace vm = ::hermes::vm;
+  auto gcConfigBuilder =
+      vm::GCConfig::Builder()
+          .withMaxHeapSize(heapSizeMB << 20)
+          .withName("RN")
+          // For the next two arguments: avoid GC before TTI by initializing the
+          // runtime to allocate directly in the old generation, but revert to
+          // normal operation when we reach the (first) TTI point.
+          .withAllocInYoung(false)
+          .withRevertToYGAtTTI(true);
+
+  if (tripWireEnabled) {
+    assert(
+        heapDumper &&
+        "Must provide a heap dumper instance if tripwire is enabled");
+
+    gcConfigBuilder.withTripwireConfig(
+        vm::GCTripwireConfig::Builder()
+            .withLimit(tripWireLimitBytes)
+            .withCooldown(msToHours(tripWireCooldownMS))
+            .withCallback([globalHeapDumper = jni::make_global(heapDumper)](
+                              vm::GCTripwireContext &ctx) mutable {
+              if (!globalHeapDumper->shouldSaveSnapshot()) {
+                return;
+              }
+
+              std::string crashId = globalHeapDumper->getId();
+              std::string path = globalHeapDumper->getInternalStorage();
+              path += "/dump_";
+              path += crashId;
+              path += ".hermes";
+
+              bool successful = ctx.createSnapshotToFile(path, true);
+              if (!successful) {
+                LOG(ERROR) << "Failed to write Hermes Memory Dump to " << path
+                           << "\n";
+                return;
+              }
+
+              LOG(INFO) << "Hermes Memory Dump saved on: " << path << "\n";
+              globalHeapDumper->setMetaData(crashId);
+            })
+            .build());
+  }
+
+  return vm::RuntimeConfig::Builder()
+      .withGCConfig(gcConfigBuilder.build())
+      .withES6Symbol(es6Symbol)
+      .withBytecodeWarmupPercent(bytecodeWarmupPercent)
+      .build();
+}
+
+static void installBindings(jsi::Runtime &runtime) {
+  react::Logger androidLogger =
+      static_cast<void (*)(const std::string &, unsigned int)>(
+          &reactAndroidLoggingHook);
+  react::bindNativeLogger(runtime, androidLogger);
+}
+
+class HermesExecutorHolder
+    : public jni::HybridClass<HermesExecutorHolder, JavaScriptExecutorHolder> {
+ public:
+  static constexpr auto kJavaDescriptor =
+      "Lcom/facebook/hermes/reactexecutor/HermesExecutor;";
+
+  static jni::local_ref<jhybriddata> initHybridDefaultConfig(
+      jni::alias_ref<jclass>) {
+    JReactMarker::setLogPerfMarkerIfNeeded();
+
+    return makeCxxInstance(
+        folly::make_unique<HermesExecutorFactory>(installBindings));
+  }
+
+  static jni::local_ref<jhybriddata> initHybrid(
+      jni::alias_ref<jclass>,
+      jlong heapSizeMB,
+      bool es6Symbol,
+      jint bytecodeWarmupPercent,
+      bool tripWireEnabled,
+      jni::alias_ref<jsi::jni::HermesMemoryDumper> heapDumper,
+      jlong tripWireCooldownMS,
+      jlong tripWireLimitBytes) {
+    JReactMarker::setLogPerfMarkerIfNeeded();
+    auto runtimeConfig = makeRuntimeConfig(
+        heapSizeMB,
+        es6Symbol,
+        bytecodeWarmupPercent,
+        tripWireEnabled,
+        heapDumper,
+        tripWireCooldownMS,
+        tripWireLimitBytes);
+    return makeCxxInstance(folly::make_unique<HermesExecutorFactory>(
+        installBindings, JSIExecutor::defaultTimeoutInvoker, runtimeConfig));
+  }
+
+  static bool canLoadFile(jni::alias_ref<jclass>, const std::string &path) {
+    return true;
+  }
+
+  static void registerNatives() {
+    registerHybrid(
+        {makeNativeMethod("initHybrid", HermesExecutorHolder::initHybrid),
+         makeNativeMethod(
+             "initHybridDefaultConfig",
+             HermesExecutorHolder::initHybridDefaultConfig),
+         makeNativeMethod("canLoadFile", HermesExecutorHolder::canLoadFile)});
+  }
+
+ private:
+  friend HybridBase;
+  using HybridBase::HybridBase;
+};
+
+} // namespace react
+} // namespace facebook
+
+JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *reserved) {
+  return facebook::jni::initialize(
+      vm, [] { facebook::react::HermesExecutorHolder::registerNatives(); });
+}

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/RuntimeConfig.java

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+package com.facebook.hermes.reactexecutor;
+
+import com.facebook.hermes.instrumentation.HermesMemoryDumper;
+import javax.annotation.Nullable;
+
+/** Holds runtime configuration for a Hermes VM instance (master or snapshot). */
+public final class RuntimeConfig {
+  public long heapSizeMB;
+  public boolean enableSampledStats;
+  public boolean es6Symbol;
+  public int bytecodeWarmupPercent;
+  public boolean tripWireEnabled;
+  @Nullable public HermesMemoryDumper heapDumper;
+  public long tripWireCooldownMS;
+  public long tripWireLimitBytes;
+}

ReactAndroid/src/main/java/com/facebook/hermes/unicode/AndroidUnicodeUtils.java

@@ -0,0 +1,75 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+package com.facebook.hermes.unicode;
+
+import java.text.Collator;
+import java.text.DateFormat;
+import java.text.Normalizer;
+import java.util.Locale;
+
+// TODO: use com.facebook.common.locale.Locales.getApplicationLocale() as the current locale,
+// rather than the device locale. This is challenging because getApplicationLocale() is only
+// available via DI.
+public class AndroidUnicodeUtils {
+  public static int localeCompare(String left, String right) {
+    Collator collator = Collator.getInstance();
+    return collator.compare(left, right);
+  }
+
+  public static String dateFormat(double unixtimeMs, boolean formatDate, boolean formatTime) {
+    DateFormat format;
+    if (formatDate && formatTime) {
+      format = DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);
+    } else if (formatDate) {
+      format = DateFormat.getDateInstance(DateFormat.MEDIUM);
+    } else if (formatTime) {
+      format = DateFormat.getTimeInstance(DateFormat.MEDIUM);
+    } else {
+      throw new RuntimeException("Bad dateFormat configuration");
+    }
+    return format.format((long) unixtimeMs).toString();
+  }
+
+  public static String convertToCase(String input, int targetCase, boolean useCurrentLocale) {
+    // These values must match CaseConversion in PlatformUnicode.h
+    final int targetUppercase = 0;
+    final int targetLowercase = 1;
+    // Note Java's case conversions use the user's locale. For example "I".toLowerCase()
+    // will produce a dotless i. From Java's docs: "To obtain correct results for locale
+    // insensitive strings, use toLowerCase(Locale.ENGLISH)."
+    Locale locale = useCurrentLocale ? Locale.getDefault() : Locale.ENGLISH;
+    switch (targetCase) {
+      case targetLowercase:
+        return input.toLowerCase(locale);
+      case targetUppercase:
+        return input.toUpperCase(locale);
+      default:
+        throw new RuntimeException("Invalid target case");
+    }
+  }
+
+  public static String normalize(String input, int form) {
+    // Values must match NormalizationForm in PlatformUnicode.h.
+    final int formC = 0;
+    final int formD = 1;
+    final int formKC = 2;
+    final int formKD = 3;
+
+    switch (form) {
+      case formC:
+        return Normalizer.normalize(input, Normalizer.Form.NFC);
+      case formD:
+        return Normalizer.normalize(input, Normalizer.Form.NFD);
+      case formKC:
+        return Normalizer.normalize(input, Normalizer.Form.NFKC);
+      case formKD:
+        return Normalizer.normalize(input, Normalizer.Form.NFKD);
+      default:
+        throw new RuntimeException("Invalid form");
+    }
+  }
+}

ReactAndroid/src/main/java/com/facebook/jni/NativeRunnable.java

@@ -16,8 +16,10 @@ import com.facebook.proguard.annotations.DoNotStrip;
 @DoNotStrip
 public class NativeRunnable implements Runnable {
 
+  @DoNotStrip
   private final HybridData mHybridData;
 
+  @DoNotStrip
   private NativeRunnable(HybridData hybridData) {
     mHybridData = hybridData;
   }

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManagerBuilder.java

@@ -10,6 +10,7 @@ import static com.facebook.react.modules.systeminfo.AndroidInfoHelpers.getFriend
 import android.app.Activity;
 import android.app.Application;
 import com.facebook.infer.annotation.Assertions;
+import com.facebook.hermes.reactexecutor.HermesExecutorFactory;
 import com.facebook.react.bridge.JSBundleLoader;
 import com.facebook.react.bridge.JSIModulePackage;
 import com.facebook.react.bridge.JavaScriptExecutorFactory;
@@ -23,6 +24,7 @@ import com.facebook.react.jscexecutor.JSCExecutorFactory;
 import com.facebook.react.modules.core.DefaultHardwareBackBtnHandler;
 import com.facebook.react.packagerconnection.RequestHandler;
 import com.facebook.react.uimanager.UIImplementationProvider;
+import com.facebook.soloader.SoLoader;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -246,6 +248,12 @@ public class ReactInstanceManagerBuilder {
       mApplication,
       "Application property has not been set with this builder");
 
+    if (mInitialLifecycleState == LifecycleState.RESUMED) {
+      Assertions.assertNotNull(
+        mCurrentActivity,
+        "Activity needs to be set if initial lifecycle state is resumed");
+    }
+
     Assertions.assertCondition(
       mUseDeveloperSupport || mJSBundleAssetUrl != null || mJSBundleLoader != null,
       "JS Bundle File or Asset URL has to be provided when dev support is disabled");
@@ -268,7 +276,7 @@ public class ReactInstanceManagerBuilder {
         mCurrentActivity,
         mDefaultHardwareBackBtnHandler,
         mJavaScriptExecutorFactory == null
-            ? new JSCExecutorFactory(appName, deviceName)
+            ? getDefaultJSExecutorFactory(appName, deviceName)
             : mJavaScriptExecutorFactory,
         (mJSBundleLoader == null && mJSBundleAssetUrl != null)
             ? JSBundleLoader.createAssetLoader(
@@ -289,4 +297,15 @@ public class ReactInstanceManagerBuilder {
         mJSIModulesPackage,
         mCustomPackagerCommandHandlers);
   }
+
+  private JavaScriptExecutorFactory getDefaultJSExecutorFactory(String appName, String deviceName) {
+    try {
+      // If JSC is included, use it as normal
+      SoLoader.loadLibrary("jscexecutor");
+      return new JSCExecutorFactory(appName, deviceName);
+    } catch(UnsatisfiedLinkError jscE) {
+      // Otherwise use Hermes
+      return new HermesExecutorFactory();
+    }
+  }
 }

ReactAndroid/src/main/java/com/facebook/react/bridge/JSBundleLoader.java

@@ -72,7 +72,7 @@ public abstract class JSBundleLoader {
           delegate.loadScriptFromFile(cachedFileLocation, sourceURL, false);
           return sourceURL;
         } catch (Exception e) {
-          throw DebugServerException.makeGeneric(e.getMessage(), e);
+          throw DebugServerException.makeGeneric(sourceURL, e.getMessage(), e);
         }
       }
     };
@@ -94,7 +94,7 @@ public abstract class JSBundleLoader {
           delegate.loadScriptFromDeltaBundle(sourceURL, nativeDeltaClient, false);
           return sourceURL;
         } catch (Exception e) {
-          throw DebugServerException.makeGeneric(e.getMessage(), e);
+          throw DebugServerException.makeGeneric(sourceURL, e.getMessage(), e);
         }
       }
     };

ReactAndroid/src/main/java/com/facebook/react/common/DebugServerException.java

@@ -11,6 +11,7 @@ import javax.annotation.Nullable;
 
 import java.io.IOException;
 
+import android.net.Uri;
 import android.text.TextUtils;
 
 import com.facebook.common.logging.FLog;
@@ -28,15 +29,19 @@ public class DebugServerException extends RuntimeException {
       "\u2022 Ensure that the packager server is running\n" +
       "\u2022 Ensure that your device/emulator is connected to your machine and has USB debugging enabled - run 'adb devices' to see a list of connected devices\n" +
       "\u2022 Ensure Airplane Mode is disabled\n" +
-      "\u2022 If you're on a physical device connected to the same machine, run 'adb reverse tcp:8081 tcp:8081' to forward requests from your device\n" +
-      "\u2022 If your device is on the same Wi-Fi network, set 'Debug server host & port for device' in 'Dev settings' to your machine's IP address and the port of the local dev server - e.g. 10.0.1.1:8081\n\n";
+      "\u2022 If you're on a physical device connected to the same machine, run 'adb reverse tcp:<PORT> tcp:<PORT>' to forward requests from your device\n" +
+      "\u2022 If your device is on the same Wi-Fi network, set 'Debug server host & port for device' in 'Dev settings' to your machine's IP address and the port of the local dev server - e.g. 10.0.1.1:<PORT>\n\n";
 
-  public static DebugServerException makeGeneric(String reason, Throwable t) {
-    return makeGeneric(reason, "", t);
+  public static DebugServerException makeGeneric(String url, String reason, Throwable t) {
+    return makeGeneric(url, reason, "", t);
   }
 
-  public static DebugServerException makeGeneric(String reason, String extra, Throwable t) {
-    return new DebugServerException(reason + GENERIC_ERROR_MESSAGE + extra, t);
+  public static DebugServerException makeGeneric(String url, String reason, String extra, Throwable t) {
+    Uri uri = Uri.parse(url);
+
+    String message = GENERIC_ERROR_MESSAGE.replace("<PORT>", String.valueOf(uri.getPort()));
+
+    return new DebugServerException(reason + message + extra, t);
   }
 
   private DebugServerException(String description, String fileName, int lineNumber, int column) {
@@ -56,7 +61,7 @@ public class DebugServerException extends RuntimeException {
    * @param str json string returned by the debug server
    * @return A DebugServerException or null if the string is not of proper form.
    */
-  @Nullable public static DebugServerException parse(String str) {
+  @Nullable public static DebugServerException parse(String url, String str) {
     if (TextUtils.isEmpty(str)) {
       return null;
     }

ReactAndroid/src/main/java/com/facebook/react/devsupport/BundleDownloader.java

@@ -142,10 +142,12 @@ public class BundleDownloader {
             }
             mDownloadBundleFromURLCall = null;
 
+            String url = call.request().url().toString();
+
             callback.onFailure(
-                DebugServerException.makeGeneric(
+                DebugServerException.makeGeneric(url,
                     "Could not connect to development server.",
-                    "URL: " + call.request().url().toString(),
+                    "URL: " + url,
                     e));
           }
 
@@ -284,7 +286,7 @@ public class BundleDownloader {
     // Check for server errors. If the server error has the expected form, fail with more info.
     if (statusCode != 200) {
       String bodyString = body.readUtf8();
-      DebugServerException debugServerException = DebugServerException.parse(bodyString);
+      DebugServerException debugServerException = DebugServerException.parse(url, bodyString);
       if (debugServerException != null) {
         callback.onFailure(debugServerException);
       } else {

ReactAndroid/src/main/java/com/facebook/react/devsupport/DevServerHelper.java

@@ -8,6 +8,7 @@
 package com.facebook.react.devsupport;
 
 import android.content.Context;
+import android.content.res.Resources;
 import android.os.AsyncTask;
 import android.os.Handler;
 import android.os.Looper;
@@ -261,7 +262,7 @@ public class DevServerHelper {
 
       public boolean doSync() {
         try {
-          String attachToNuclideUrl = getInspectorAttachUrl(title);
+          String attachToNuclideUrl = getInspectorAttachUrl(context, title);
           OkHttpClient client = new OkHttpClient();
           Request request = new Request.Builder().url(attachToNuclideUrl).build();
           client.newCall(request).execute();
@@ -367,11 +368,11 @@ public class DevServerHelper {
         mPackageName);
   }
 
-  private String getInspectorAttachUrl(String title) {
+  private String getInspectorAttachUrl(Context context, String title) {
     return String.format(
         Locale.US,
         "http://%s/nuclide/attach-debugger-nuclide?title=%s&app=%s&device=%s",
-        AndroidInfoHelpers.getServerHost(),
+        AndroidInfoHelpers.getServerHost(context),
         title,
         mPackageName,
         AndroidInfoHelpers.getFriendlyDeviceName());

ReactAndroid/src/main/java/com/facebook/react/modules/intent/IntentModule.java

@@ -12,6 +12,7 @@ import android.content.ComponentName;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.net.Uri;
+import android.nfc.NfcAdapter;
 import android.provider.Settings;
 
 import com.facebook.react.bridge.JSApplicationIllegalArgumentException;
@@ -59,7 +60,7 @@ public class IntentModule extends ReactContextBaseJavaModule {
         String action = intent.getAction();
         Uri uri = intent.getData();
 
-        if (Intent.ACTION_VIEW.equals(action) && uri != null) {
+        if (uri != null && (Intent.ACTION_VIEW.equals(action) || NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action))) {
           initialURL = uri.toString();
         }
       }

ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/AndroidInfoHelpers.java

@@ -8,12 +8,14 @@ package com.facebook.react.modules.systeminfo;
 import java.io.BufferedReader;
 import java.io.InputStreamReader;
 import java.nio.charset.Charset;
-import java.nio.charset.StandardCharsets;
 import java.util.Locale;
 
+import android.content.Context;
+import android.content.res.Resources;
 import android.os.Build;
 
 import com.facebook.common.logging.FLog;
+import com.facebook.react.R;
 
 public class AndroidInfoHelpers {
 
@@ -23,9 +25,6 @@ public class AndroidInfoHelpers {
 
   public static final String METRO_HOST_PROP_NAME = "metro.host";
 
-  private static final int DEBUG_SERVER_HOST_PORT = 8081;
-  private static final int INSPECTOR_PROXY_PORT = 8081;
-
   private static final String TAG = AndroidInfoHelpers.class.getSimpleName();
 
   private static boolean isRunningOnGenymotion() {
@@ -36,12 +35,24 @@ public class AndroidInfoHelpers {
     return Build.FINGERPRINT.contains("generic");
   }
 
-  public static String getServerHost() {
-    return getServerIpAddress(DEBUG_SERVER_HOST_PORT);
+  public static String getServerHost(Integer port) {
+    return getServerIpAddress(port);
   }
 
-  public static String getInspectorProxyHost() {
-    return getServerIpAddress(INSPECTOR_PROXY_PORT);
+  public static String getServerHost(Context context) {
+    return getServerIpAddress(getDevServerPort(context));
+  }
+
+  public static String getAdbReverseTcpCommand(Integer port) {
+    return "adb reverse tcp:" + port + " tcp:" + port;
+  }
+
+  public static String getAdbReverseTcpCommand(Context context) {
+    return getAdbReverseTcpCommand(getDevServerPort(context));
+  }
+
+  public static String getInspectorProxyHost(Context context) {
+    return getServerIpAddress(getInspectorProxyPort(context));
   }
 
   // WARNING(festevezga): This RN helper method has been copied to another FB-only target. Any changes should be applied to both.
@@ -54,6 +65,16 @@ public class AndroidInfoHelpers {
     }
   }
 
+  private static Integer getDevServerPort(Context context) {
+    Resources resources = context.getResources();
+    return resources.getInteger(R.integer.react_native_dev_server_port);
+  }
+
+  private static Integer getInspectorProxyPort(Context context) {
+    Resources resources = context.getResources();
+    return resources.getInteger(R.integer.react_native_dev_server_port);
+  }
+
   private static String getServerIpAddress(int port) {
     // Since genymotion runs in vbox it use different hostname to refer to adb host.
     // We detect whether app runs on genymotion and replace js bundle server hostname accordingly

ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/AndroidInfoModule.java

@@ -9,10 +9,13 @@ package com.facebook.react.modules.systeminfo;
 
 import android.annotation.SuppressLint;
 import android.app.UiModeManager;
+import android.content.Context;
 import android.content.res.Configuration;
+import android.content.res.Resources;
 import android.os.Build;
 import android.provider.Settings.Secure;
 
+import com.facebook.react.R;
 import com.facebook.react.bridge.ReactApplicationContext;
 import com.facebook.react.bridge.ReactContextBaseJavaModule;
 import com.facebook.react.common.build.ReactBuildConfig;
@@ -35,9 +38,7 @@ public class AndroidInfoModule extends ReactContextBaseJavaModule {
   public static final String NAME = "PlatformConstants";
   private static final String IS_TESTING = "IS_TESTING";
 
-  public AndroidInfoModule(ReactApplicationContext reactContext) {
-    super(reactContext);
-  }
+  public AndroidInfoModule(ReactApplicationContext reactContext) { super(reactContext); }
 
   /**
    * See: https://developer.android.com/reference/android/app/UiModeManager.html#getCurrentModeType()
@@ -74,7 +75,7 @@ public class AndroidInfoModule extends ReactContextBaseJavaModule {
     constants.put("Fingerprint", Build.FINGERPRINT);
     constants.put("Model", Build.MODEL);
     if (ReactBuildConfig.DEBUG) {
-      constants.put("ServerHost", AndroidInfoHelpers.getServerHost());
+      constants.put("ServerHost", getServerHost());
     }
     constants.put("isTesting", "true".equals(System.getProperty(IS_TESTING))
     || isRunningScreenshotTest());
@@ -96,4 +97,12 @@ public class AndroidInfoModule extends ReactContextBaseJavaModule {
       return false;
     }
   }
+
+  private String getServerHost() {
+    Resources resources = getReactApplicationContext().getApplicationContext().getResources();
+
+    Integer devServerPort = resources.getInteger(R.integer.react_native_dev_server_port);
+
+    return AndroidInfoHelpers.getServerHost(devServerPort);
+  }
 }

ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/BUCK

@@ -14,6 +14,7 @@ rn_android_library(
         react_native_target("java/com/facebook/react/bridge:bridge"),
         react_native_target("java/com/facebook/react/common:common"),
         react_native_target("java/com/facebook/react/module/annotations:annotations"),
+        react_native_target("res:systeminfo"),
     ],
     exported_deps = [
         ":systeminfo-moduleless",
@@ -29,8 +30,10 @@ rn_android_library(
         "PUBLIC",
     ],
     deps = [
+        react_native_target("java/com/facebook/react/common:common"),
         react_native_dep("libraries/fbcore/src/main/java/com/facebook/common/logging:logging"),
         react_native_dep("third-party/java/infer-annotations:infer-annotations"),
         react_native_dep("third-party/java/jsr-305:jsr-305"),
+        react_native_target("res:systeminfo"),
     ],
 )

ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/ReactNativeVersion.java

@@ -16,7 +16,7 @@ import java.util.Map;
 public class ReactNativeVersion {
   public static final Map<String, Object> VERSION = MapBuilder.<String, Object>of(
       "major", 0,
-      "minor", 0,
-      "patch", 0,
+      "minor", 60,
+      "patch", 2,
       "prerelease", null);
 }

ReactAndroid/src/main/java/com/facebook/react/packagerconnection/PackagerConnectionSettings.java

@@ -7,13 +7,13 @@
 
 package com.facebook.react.packagerconnection;
 
-import javax.annotation.Nullable;
-
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 import android.text.TextUtils;
 
+import javax.annotation.Nullable;
+
 import com.facebook.common.logging.FLog;
 import com.facebook.infer.annotation.Assertions;
 import com.facebook.react.modules.systeminfo.AndroidInfoHelpers;
@@ -24,10 +24,12 @@ public class PackagerConnectionSettings {
 
   private final SharedPreferences mPreferences;
   private final String mPackageName;
+  private final Context mAppContext;
 
   public PackagerConnectionSettings(Context applicationContext) {
     mPreferences = PreferenceManager.getDefaultSharedPreferences(applicationContext);
     mPackageName = applicationContext.getPackageName();
+    mAppContext = applicationContext;
   }
 
   public String getDebugServerHost() {
@@ -39,12 +41,12 @@ public class PackagerConnectionSettings {
       return Assertions.assertNotNull(hostFromSettings);
     }
 
-    String host = AndroidInfoHelpers.getServerHost();
+    String host = AndroidInfoHelpers.getServerHost(mAppContext);
 
     if (host.equals(AndroidInfoHelpers.DEVICE_LOCALHOST)) {
       FLog.w(
         TAG,
-        "You seem to be running on device. Run 'adb reverse tcp:8081 tcp:8081' " +
+        "You seem to be running on device. Run '" + AndroidInfoHelpers.getAdbReverseTcpCommand(mAppContext) + "' " +
           "to forward the debug server's port to the device.");
     }
 
@@ -52,7 +54,7 @@ public class PackagerConnectionSettings {
   }
 
   public String getInspectorServerHost() {
-    return AndroidInfoHelpers.getInspectorProxyHost();
+    return AndroidInfoHelpers.getInspectorProxyHost(mAppContext);
   }
 
   public @Nullable String getPackageName() {

ReactAndroid/src/main/java/com/facebook/react/views/text/CustomStyleSpan.java

@@ -104,7 +104,7 @@ public class CustomStyleSpan extends MetricAffectingSpan implements ReactSpan {
     }
 
     if (family != null) {
-      typeface = ReactFontManager.getInstance().getTypeface(family, want, assetManager);
+      typeface = ReactFontManager.getInstance().getTypeface(family, want, weight, assetManager);
     } else if (typeface != null) {
       // TODO(t9055065): Fix custom fonts getting applied to text children with different style
       typeface = Typeface.create(typeface, want);

ReactAndroid/src/main/java/com/facebook/react/views/text/ReactBaseTextShadowNode.java

@@ -309,7 +309,7 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
             && fontWeightString.charAt(0) <= '9'
             && fontWeightString.charAt(0) >= '1'
         ? 100 * (fontWeightString.charAt(0) - '0')
-        : -1;
+        : UNSET;
   }
 
   protected TextAttributes mTextAttributes;
@@ -459,8 +459,8 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     markUpdated();
   }
 
-  @ReactProp(name = ViewProps.BACKGROUND_COLOR)
-  public void setBackgroundColor(Integer color) {
+  @ReactProp(name = ViewProps.BACKGROUND_COLOR, customType = "Color")
+  public void setBackgroundColor(@Nullable Integer color) {
     // Background color needs to be handled here for virtual nodes so it can be incorporated into
     // the span. However, it doesn't need to be applied to non-virtual nodes because non-virtual
     // nodes get mapped to native views and native views get their background colors get set via
@@ -487,14 +487,12 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
   @ReactProp(name = ViewProps.FONT_WEIGHT)
   public void setFontWeight(@Nullable String fontWeightString) {
     int fontWeightNumeric =
-        fontWeightString != null ? parseNumericFontWeight(fontWeightString) : -1;
-    int fontWeight = UNSET;
-    if (fontWeightNumeric >= 500 || "bold".equals(fontWeightString)) {
-      fontWeight = Typeface.BOLD;
-    } else if ("normal".equals(fontWeightString)
-        || (fontWeightNumeric != -1 && fontWeightNumeric < 500)) {
-      fontWeight = Typeface.NORMAL;
-    }
+        fontWeightString != null ? parseNumericFontWeight(fontWeightString) : UNSET;
+    int fontWeight = fontWeightNumeric != UNSET ? fontWeightNumeric : Typeface.NORMAL;
+
+    if (fontWeight == 700 || "bold".equals(fontWeightString)) fontWeight = Typeface.BOLD;
+    else if (fontWeight == 400 || "normal".equals(fontWeightString)) fontWeight = Typeface.NORMAL;
+
     if (fontWeight != mFontWeight) {
       mFontWeight = fontWeight;
       markUpdated();

ReactAndroid/src/main/java/com/facebook/react/views/text/ReactFontManager.java

@@ -13,6 +13,7 @@ import java.util.Map;
 import android.content.Context;
 import android.content.res.AssetManager;
 import android.graphics.Typeface;
+import android.os.Build;
 import android.util.SparseArray;
 
 import androidx.annotation.NonNull;
@@ -54,23 +55,32 @@ public class ReactFontManager {
     return sReactFontManagerInstance;
   }
 
+  public @Nullable Typeface getTypeface(
+    String fontFamilyName,
+    int style,
+    AssetManager assetManager) {
+    return getTypeface(fontFamilyName, style, 0, assetManager);
+  }
+
   public @Nullable Typeface getTypeface(
       String fontFamilyName,
       int style,
+      int weight,
       AssetManager assetManager) {
+    if(mCustomTypefaceCache.containsKey(fontFamilyName)) {
+      Typeface typeface = mCustomTypefaceCache.get(fontFamilyName);
+      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P && weight >= 100 && weight <= 1000) {
+        return Typeface.create(typeface, weight, (style & Typeface.ITALIC) != 0);
+      }
+      return Typeface.create(typeface, style);
+    }
+
     FontFamily fontFamily = mFontCache.get(fontFamilyName);
     if (fontFamily == null) {
       fontFamily = new FontFamily();
       mFontCache.put(fontFamilyName, fontFamily);
     }
 
-    if(mCustomTypefaceCache.containsKey(fontFamilyName)) {
-      return Typeface.create(
-        mCustomTypefaceCache.get(fontFamilyName),
-        style
-      );
-    }
-
     Typeface typeface = fontFamily.getTypeface(style);
     if (typeface == null) {
       typeface = createTypeface(fontFamilyName, style, assetManager);

ReactAndroid/src/main/java/com/facebook/react/views/text/ReactTextShadowNode.java

@@ -115,6 +115,9 @@ public class ReactTextShadowNode extends ReactBaseTextShadowNode {
               if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                 builder.setJustificationMode(mJustificationMode);
               }
+              if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+                  builder.setUseLineSpacingFromFallbacks(true);
+              }
               layout = builder.build();
             }
 
@@ -139,14 +142,18 @@ public class ReactTextShadowNode extends ReactBaseTextShadowNode {
                   new StaticLayout(
                       text, textPaint, (int) width, alignment, 1.f, 0.f, mIncludeFontPadding);
             } else {
-              layout =
+              StaticLayout.Builder builder =
                   StaticLayout.Builder.obtain(text, 0, text.length(), textPaint, (int) width)
                       .setAlignment(alignment)
                       .setLineSpacing(0.f, 1.f)
                       .setIncludePad(mIncludeFontPadding)
                       .setBreakStrategy(mTextBreakStrategy)
-                      .setHyphenationFrequency(Layout.HYPHENATION_FREQUENCY_NORMAL)
-                      .build();
+                      .setHyphenationFrequency(Layout.HYPHENATION_FREQUENCY_NORMAL);
+
+              if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+                  builder.setUseLineSpacingFromFallbacks(true);
+              }
+              layout = builder.build();
             }
           }
 

ReactAndroid/src/main/jni/Application.mk

@@ -26,9 +26,9 @@ NDK_MODULE_PATH := $(APP_MK_DIR)$(HOST_DIRSEP)$(THIRD_PARTY_NDK_DIR)$(HOST_DIRSE
 
 APP_STL := c++_shared
 
-# Make sure every shared lib includes a .note.gnu.build-id header
-APP_CFLAGS := -Wall -Werror -fexceptions -frtti
+APP_CFLAGS := -Wall -Werror -fexceptions -frtti -DWITH_INSPECTOR=1
 APP_CPPFLAGS := -std=c++1y
+# Make sure every shared lib includes a .note.gnu.build-id header
 APP_LDFLAGS := -Wl,--build-id
 
 NDK_TOOLCHAIN_VERSION := clang

ReactAndroid/src/main/jni/first-party/hermes/Android.mk

@@ -0,0 +1,5 @@
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+LOCAL_MODULE:= hermes
+LOCAL_SRC_FILES := jni/$(TARGET_ARCH_ABI)/libhermes.so
+include $(PREBUILT_SHARED_LIBRARY)

ReactAndroid/src/main/jni/react/jni/Android.mk

@@ -60,6 +60,7 @@ $(call import-module,cxxreact)
 $(call import-module,jsi)
 $(call import-module,jsiexecutor)
 $(call import-module,jscallinvoker)
+$(call import-module,hermes)
 
 include $(REACT_SRC_DIR)/turbomodule/core/jni/Android.mk
 
@@ -68,3 +69,4 @@ include $(REACT_SRC_DIR)/turbomodule/core/jni/Android.mk
 # $(call import-module,jscexecutor)
 
 include $(REACT_SRC_DIR)/jscexecutor/Android.mk
+include $(REACT_SRC_DIR)/../hermes/reactexecutor/Android.mk

ReactAndroid/src/main/jni/react/jni/CatalystInstanceImpl.cpp

@@ -199,6 +199,8 @@ void CatalystInstanceImpl::jniLoadScriptFromAssets(
       sourceURL,
       loadSynchronously);
     return;
+  } else if (Instance::isIndexedRAMBundle(&script)) {
+    instance_->loadRAMBundleFromString(std::move(script), sourceURL);
   } else {
     instance_->loadScriptFromString(std::move(script), sourceURL, loadSynchronously);
   }

ReactAndroid/src/main/jni/third-party/folly/Android.mk

@@ -65,7 +65,7 @@ LOCAL_SRC_FILES := \
   folly/memory/MallctlHelper.cpp \
   folly/portability/SysMembarrier.cpp \
   folly/synchronization/AsymmetricMemoryBarrier.cpp \
-  folly/synchronization/HazPtr.cpp \
+  folly/synchronization/Hazptr.cpp \
   folly/synchronization/ParkingLot.cpp \
   folly/synchronization/WaitOptions.cpp
 

ReactAndroid/src/main/libraries/fresco/fresco-react-native/BUCK

@@ -9,8 +9,8 @@ rn_android_prebuilt_aar(
 
 fb_native.remote_file(
     name = "fresco-binary-aar",
-    sha1 = "0369d4ac5a48cbd748854ea9043c88b807940fb3",
-    url = "mvn:com.facebook.fresco:fresco:aar:1.13.0",
+    sha1 = "d473020b37b7cdd3171154942b55021a55a9d990",
+    url = "mvn:com.facebook.fresco:fresco:aar:2.0.0",
 )
 
 rn_android_prebuilt_aar(
@@ -21,8 +21,8 @@ rn_android_prebuilt_aar(
 
 fb_native.remote_file(
     name = "drawee-binary-aar",
-    sha1 = "b846ceec4b708b630693fedb79c85aabd1dbdeed",
-    url = "mvn:com.facebook.fresco:drawee:aar:1.13.0",
+    sha1 = "a85bfaeb87a9c8d1521c70edf6ded91ff9999475",
+    url = "mvn:com.facebook.fresco:drawee:aar:2.0.0",
 )
 
 rn_android_library(
@@ -44,8 +44,8 @@ rn_android_prebuilt_aar(
 
 fb_native.remote_file(
     name = "imagepipeline-base-aar",
-    sha1 = "3c4b6613a59825951d3c2b3a5accdbdfd667d9cb",
-    url = "mvn:com.facebook.fresco:imagepipeline-base:aar:1.13.0",
+    sha1 = "d27635390665d433f987177c548d25d0473eadbe",
+    url = "mvn:com.facebook.fresco:imagepipeline-base:aar:2.0.0",
 )
 
 rn_android_prebuilt_aar(
@@ -56,8 +56,8 @@ rn_android_prebuilt_aar(
 
 fb_native.remote_file(
     name = "imagepipeline-aar",
-    sha1 = "405fa064f139b495e0e857661a5706cfb22eafdf",
-    url = "mvn:com.facebook.fresco:imagepipeline:aar:1.13.0",
+    sha1 = "7bc59327fb4895c465cbfeede700daf349ea56da",
+    url = "mvn:com.facebook.fresco:imagepipeline:aar:2.0.0",
 )
 
 rn_android_prebuilt_aar(
@@ -69,7 +69,7 @@ rn_android_prebuilt_aar(
 remote_file(
     name = "nativeimagefilters-aar",
     sha1 = "f49525db580abc4d2fb0a74fac771fc6c69f2adb",
-    url = "mvn:com.facebook.fresco:nativeimagefilters:aar:1.13.0",
+    url = "mvn:com.facebook.fresco:nativeimagefilters:aar:2.0.0",
 )
 
 rn_prebuilt_jar(
@@ -92,8 +92,8 @@ rn_android_prebuilt_aar(
 
 fb_native.remote_file(
     name = "fbcore-aar",
-    sha1 = "f8dd8ba9d7ea60dc54b5fba4ed5f6feacc5e596f",
-    url = "mvn:com.facebook.fresco:fbcore:aar:1.13.0",
+    sha1 = "8de91f71e8aa84a4d9be4dd88d1a0ac51600ad60",
+    url = "mvn:com.facebook.fresco:fbcore:aar:2.0.0",
 )
 
 rn_android_prebuilt_aar(
@@ -105,5 +105,5 @@ rn_android_prebuilt_aar(
 fb_native.remote_file(
     name = "imagepipeline-okhttp3-binary-aar",
     sha1 = "bc1212ca66cd09678b416894ea8bd04102d26c5f",
-    url = "mvn:com.facebook.fresco:imagepipeline-okhttp3:aar:1.13.0",
+    url = "mvn:com.facebook.fresco:imagepipeline-okhttp3:aar:2.0.0",
 )

ReactAndroid/src/main/res/BUCK

@@ -36,4 +36,13 @@ rn_android_resource(
     ],
 )
 
+rn_android_resource(
+    name = "systeminfo",
+    package = "com.facebook.react",
+    res = "systeminfo",
+    visibility = [
+        "PUBLIC",
+    ],
+)
+
 # New resource directories must be added to react-native-github/ReactAndroid/build.gradle

ReactAndroid/src/main/res/systeminfo/values/values.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <integer name="react_native_dev_server_port">8081</integer>
+  <integer name="react_native_inspector_proxy_port">@integer/react_native_dev_server_port</integer>
+</resources>

ReactCommon/cxxreact/Android.mk

@@ -30,3 +30,4 @@ $(call import-module,jsc)
 $(call import-module,glog)
 $(call import-module,jsi)
 $(call import-module,jsinspector)
+$(call import-module,hermes/inspector)

ReactCommon/cxxreact/Instance.cpp

@@ -108,6 +108,24 @@ bool Instance::isIndexedRAMBundle(const char *sourcePath) {
   return parseTypeFromHeader(header) == ScriptTag::RAMBundle;
 }
 
+bool Instance::isIndexedRAMBundle(std::unique_ptr<const JSBigString>* script) {
+  BundleHeader header;
+  strncpy(reinterpret_cast<char *>(&header), script->get()->c_str(), sizeof(header));
+
+  return parseTypeFromHeader(header) == ScriptTag::RAMBundle;
+}
+
+void Instance::loadRAMBundleFromString(std::unique_ptr<const JSBigString> script, const std::string& sourceURL) {
+  auto bundle = folly::make_unique<JSIndexedRAMBundle>(std::move(script));
+  auto startupScript = bundle->getStartupCode();
+  auto registry = RAMBundleRegistry::singleBundleRegistry(std::move(bundle));
+  loadRAMBundle(
+    std::move(registry),
+    std::move(startupScript),
+    sourceURL,
+    true);
+}
+
 void Instance::loadRAMBundleFromFile(const std::string& sourcePath,
                            const std::string& sourceURL,
                            bool loadSynchronously) {

ReactCommon/cxxreact/Instance.h

@@ -47,6 +47,8 @@ public:
   void loadScriptFromString(std::unique_ptr<const JSBigString> string,
                             std::string sourceURL, bool loadSynchronously);
   static bool isIndexedRAMBundle(const char *sourcePath);
+  static bool isIndexedRAMBundle(std::unique_ptr<const JSBigString>* string);
+  void loadRAMBundleFromString(std::unique_ptr<const JSBigString> script, const std::string& sourceURL);
   void loadRAMBundleFromFile(const std::string& sourcePath,
                              const std::string& sourceURL,
                              bool loadSynchronously);

ReactCommon/cxxreact/JSIndexedRAMBundle.cpp

@@ -6,7 +6,8 @@
 #include "JSIndexedRAMBundle.h"
 
 #include <glog/logging.h>
-
+#include <fstream>
+#include <sstream>
 #include <folly/Memory.h>
 
 namespace facebook {
@@ -18,14 +19,30 @@ std::function<std::unique_ptr<JSModulesUnbundle>(std::string)> JSIndexedRAMBundl
   };
 }
 
-JSIndexedRAMBundle::JSIndexedRAMBundle(const char *sourcePath) :
-    m_bundle (sourcePath, std::ios_base::in) {
+JSIndexedRAMBundle::JSIndexedRAMBundle(const char *sourcePath) {
+  m_bundle = std::make_unique<std::ifstream>(sourcePath, std::ifstream::binary);
   if (!m_bundle) {
     throw std::ios_base::failure(
       folly::to<std::string>("Bundle ", sourcePath,
-                             "cannot be opened: ", m_bundle.rdstate()));
+                             "cannot be opened: ", m_bundle->rdstate()));
   }
+  init();
+}
 
+JSIndexedRAMBundle::JSIndexedRAMBundle(std::unique_ptr<const JSBigString> script) {
+  // tmpStream is needed because m_bundle is std::istream type
+  // which has no member 'write'
+  std::unique_ptr<std::stringstream> tmpStream = std::make_unique<std::stringstream>();
+  tmpStream->write(script->c_str(), script->size());
+  m_bundle = std::move(tmpStream);
+  if (!m_bundle) {
+    throw std::ios_base::failure(
+      folly::to<std::string>("Bundle from string cannot be opened: ", m_bundle->rdstate()));
+  }
+  init();
+}
+
+void JSIndexedRAMBundle::init() {
   // read in magic header, number of entries, and length of the startup section
   uint32_t header[3];
   static_assert(
@@ -78,12 +95,12 @@ std::string JSIndexedRAMBundle::getModuleCode(const uint32_t id) const {
 }
 
 void JSIndexedRAMBundle::readBundle(char *buffer, const std::streamsize bytes) const {
-  if (!m_bundle.read(buffer, bytes)) {
-    if (m_bundle.rdstate() & std::ios::eofbit) {
+  if (!m_bundle->read(buffer, bytes)) {
+    if (m_bundle->rdstate() & std::ios::eofbit) {
       throw std::ios_base::failure("Unexpected end of RAM Bundle file");
     }
     throw std::ios_base::failure(
-      folly::to<std::string>("Error reading RAM Bundle: ", m_bundle.rdstate()));
+      folly::to<std::string>("Error reading RAM Bundle: ", m_bundle->rdstate()));
   }
 }
 
@@ -92,9 +109,9 @@ void JSIndexedRAMBundle::readBundle(
     const std::streamsize bytes,
     const std::ifstream::pos_type position) const {
 
-  if (!m_bundle.seekg(position)) {
+  if (!m_bundle->seekg(position)) {
     throw std::ios_base::failure(
-      folly::to<std::string>("Error reading RAM Bundle: ", m_bundle.rdstate()));
+      folly::to<std::string>("Error reading RAM Bundle: ", m_bundle->rdstate()));
   }
   readBundle(buffer, bytes);
 }

ReactCommon/cxxreact/JSIndexedRAMBundle.h

@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <fstream>
+#include <istream>
 #include <memory>
 
 #include <cxxreact/JSBigString.h>
@@ -24,6 +24,7 @@ public:
 
   // Throws std::runtime_error on failure.
   JSIndexedRAMBundle(const char *sourceURL);
+  JSIndexedRAMBundle(std::unique_ptr<const JSBigString> script);
 
   // Throws std::runtime_error on failure.
   std::unique_ptr<const JSBigString> getStartupCode();
@@ -51,14 +52,15 @@ private:
     }
   };
 
+  void init();
   std::string getModuleCode(const uint32_t id) const;
   void readBundle(char *buffer, const std::streamsize bytes) const;
   void readBundle(
     char *buffer, const
     std::streamsize bytes,
-    const std::ifstream::pos_type position) const;
+    const std::istream::pos_type position) const;
 
-  mutable std::ifstream m_bundle;
+  mutable std::unique_ptr<std::istream> m_bundle;
   ModuleTable m_table;
   size_t m_baseOffset;
   std::unique_ptr<JSBigBufferString> m_startupCode;

ReactCommon/hermes/inspector/.clang-format

@@ -0,0 +1,87 @@
+---
+AccessModifierOffset: -1
+AlignAfterOpenBracket: AlwaysBreak
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlinesLeft: true
+AlignOperands:   false
+AlignTrailingComments: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Empty
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: true
+AlwaysBreakTemplateDeclarations: true
+BinPackArguments: false
+BinPackParameters: false
+BraceWrapping:
+  AfterClass:      false
+  AfterControlStatement: false
+  AfterEnum:       false
+  AfterFunction:   false
+  AfterNamespace:  false
+  AfterObjCDeclaration: false
+  AfterStruct:     false
+  AfterUnion:      false
+  BeforeCatch:     false
+  BeforeElse:      false
+  IndentBraces:    false
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Attach
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: false
+ColumnLimit:     80
+CommentPragmas:  '^ IWYU pragma:'
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: false
+DisableFormat:   false
+ForEachMacros:   [ FOR_EACH_RANGE, FOR_EACH, ]
+IncludeCategories:
+  - Regex:           '^<.*\.h(pp)?>'
+    Priority:        1
+  - Regex:           '^<.*'
+    Priority:        2
+  - Regex:           '.*'
+    Priority:        3
+IndentCaseLabels: true
+IndentWidth:     2
+IndentWrappedFunctionNames: false
+KeepEmptyLinesAtTheStartOfBlocks: false
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBlockIndentWidth: 2
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: false
+PenaltyBreakBeforeFirstCallParameter: 1
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 200
+PointerAlignment: Right
+ReflowComments:  true
+SortIncludes:    true
+SpaceAfterCStyleCast: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeParens: ControlStatements
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles:  false
+SpacesInContainerLiterals: true
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard:        Cpp11
+TabWidth:        8
+UseTab:          Never
+...

ReactCommon/hermes/inspector/Android.mk

@@ -0,0 +1,26 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+REACT_NATIVE := $(LOCAL_PATH)/../../..
+
+LOCAL_MODULE := hermes-inspector
+
+LOCAL_SRC_FILES := $(wildcard $(LOCAL_PATH)/*.cpp $(LOCAL_PATH)/detail/*.cpp $(LOCAL_PATH)/chrome/*.cpp)
+
+LOCAL_C_ROOT := $(LOCAL_PATH)/../..
+
+LOCAL_CFLAGS := -DHERMES_ENABLE_DEBUGGER=1
+LOCAL_C_INCLUDES := $(LOCAL_C_ROOT) $(REACT_NATIVE)/ReactCommon/jsi $(REACT_NATIVE)/node_modules/hermesvm/android/include
+LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_ROOT)
+
+LOCAL_CPP_FEATURES := exceptions
+
+LOCAL_STATIC_LIBRARIES := libjsi
+LOCAL_SHARED_LIBRARIES := jsinspector libfb libfolly_futures libfolly_json libhermes
+
+include $(BUILD_SHARED_LIBRARY)

ReactCommon/hermes/inspector/AsyncPauseState.h

@@ -0,0 +1,29 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+
+/**
+ * AsyncPauseState is used to track whether we requested an async pause from a
+ * running VM, and whether the pause was initiated by us or by the client.
+ */
+enum class AsyncPauseState {
+  /// None means there is no pending async pause in the VM.
+  None,
+
+  /// Implicit means we requested an async pause from the VM to service an op
+  /// that can only be performed while paused, like setting a breakpoint. An
+  /// impliict pause can be upgraded to an explicit pause if the client later
+  /// explicitly requests a pause.
+  Implicit,
+
+  /// Explicit means that the client requested the pause by calling pause().
+  Explicit
+};
+
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/BUCK

@@ -0,0 +1,221 @@
+# Copyright 2004-present Facebook. All Rights Reserved.
+
+load("@fbsource//tools/build_defs:default_platform_defs.bzl", "APPLE", "CXX")
+load("@fbsource//tools/build_defs:fb_xplat_cxx_binary.bzl", "fb_xplat_cxx_binary")
+load("@fbsource//tools/build_defs:fb_xplat_cxx_library.bzl", "fb_xplat_cxx_library")
+load("@fbsource//tools/build_defs:fb_xplat_cxx_test.bzl", "fb_xplat_cxx_test")
+load("@fbsource//tools/build_defs/oss:rn_defs.bzl", "react_native_xplat_target")
+load("@fbsource//xplat/hermes/defs:hermes.bzl", "hermes_build_mode", "hermes_optimize_flag")
+
+CFLAGS_BY_MODE = {
+    "dbg": [
+        "-fexceptions",
+        "-frtti",
+        hermes_optimize_flag("dbg"),
+        "-g",
+    ],
+    "dev": [
+        "-fexceptions",
+        "-frtti",
+        hermes_optimize_flag("dev"),
+        "-g",
+    ],
+    "opt": [
+        "-fexceptions",
+        "-frtti",
+        hermes_optimize_flag("opt"),
+    ],
+}
+
+CHROME_EXPORTED_HEADERS = [
+    "chrome/AutoAttachUtils.h",
+    "chrome/Connection.h",
+    "chrome/ConnectionDemux.h",
+    "chrome/MessageConverters.h",
+    "chrome/MessageInterfaces.h",
+    "chrome/MessageTypes.h",
+    "chrome/Registration.h",
+    "chrome/RemoteObjectsTable.h",
+]
+
+fb_xplat_cxx_library(
+    name = "chrome",
+    srcs = glob(["chrome/*.cpp"]),
+    headers = glob(
+        [
+            "chrome/*.h",
+        ],
+        exclude = CHROME_EXPORTED_HEADERS,
+    ),
+    header_namespace = "hermes/inspector",
+    exported_headers = CHROME_EXPORTED_HEADERS,
+    compiler_flags = CFLAGS_BY_MODE[hermes_build_mode()],
+    fbobjc_header_path_prefix = "hermes/inspector/chrome",
+    macosx_tests_override = [],
+    tests = [":chrome-tests"],
+    visibility = [
+        "PUBLIC",
+    ],
+    xcode_public_headers_symlinks = True,
+    deps = [
+        react_native_xplat_target("jsinspector:jsinspector"),
+        "fbsource//xplat/folly:futures",
+        "fbsource//xplat/folly:molly",
+        "fbsource//xplat/hermes/API:HermesAPI",
+        "fbsource//xplat/jsi:jsi",
+        "fbsource//xplat/third-party/glog:glog",
+        ":detail",
+        ":inspectorlib",
+    ],
+)
+
+fb_xplat_cxx_test(
+    name = "chrome-tests",
+    srcs = glob([
+        "chrome/tests/*.cpp",
+    ]),
+    headers = glob([
+        "chrome/tests/*.h",
+    ]),
+    compiler_flags = CFLAGS_BY_MODE[hermes_build_mode()],
+    cxx_deps = [react_native_xplat_target("jsinspector:jsinspector")],
+    fbandroid_deps = [react_native_xplat_target("jsinspector:jsinspector")],
+    fbobjc_deps = [react_native_xplat_target("jsinspector:jsinspector")],
+    visibility = [
+        "PUBLIC",
+    ],
+    deps = [
+        "fbsource//xplat/third-party/gmock:gtest",
+        ":chrome",
+        ":detail",
+    ],
+)
+
+DETAIL_EXPORTED_HEADERS = [
+    "detail/SerialExecutor.h",
+    "detail/Thread.h",
+]
+
+fb_xplat_cxx_library(
+    name = "detail",
+    srcs = glob(["detail/*.cpp"]),
+    headers = glob(
+        [
+            "detail/*.h",
+        ],
+        exclude = DETAIL_EXPORTED_HEADERS,
+    ),
+    header_namespace = "hermes/inspector",
+    exported_headers = DETAIL_EXPORTED_HEADERS,
+    compiler_flags = CFLAGS_BY_MODE[hermes_build_mode()],
+    # This is required by lint, but must be False, because there is
+    # no JNI_Onload.
+    fbandroid_allow_jni_merging = False,
+    fbandroid_deps = [
+        "fbandroid//native/fb:fb",
+    ],
+    fbobjc_header_path_prefix = "hermes/inspector/detail",
+    macosx_tests_override = [],
+    tests = [":detail-tests"],
+    visibility = [
+        "PUBLIC",
+    ],
+    xcode_public_headers_symlinks = True,
+    deps = [
+        "fbsource//xplat/folly:molly",
+    ],
+)
+
+fb_xplat_cxx_test(
+    name = "detail-tests",
+    srcs = glob([
+        "detail/tests/*.cpp",
+    ]),
+    headers = glob([
+        "detail/tests/*.h",
+    ]),
+    compiler_flags = CFLAGS_BY_MODE[hermes_build_mode()],
+    visibility = [
+        "PUBLIC",
+    ],
+    deps = [
+        "fbsource//xplat/third-party/gmock:gtest",
+        ":detail",
+    ],
+)
+
+fb_xplat_cxx_binary(
+    name = "hermes-chrome-debug-server",
+    srcs = glob([
+        "chrome/cli/*.cpp",
+    ]),
+    compiler_flags = CFLAGS_BY_MODE[hermes_build_mode()],
+    cxx_deps = [react_native_xplat_target("jsinspector:jsinspector")],
+    fbandroid_deps = [react_native_xplat_target("jsinspector:jsinspector")],
+    fbobjc_deps = [react_native_xplat_target("jsinspector:jsinspector")],
+    visibility = [
+        "PUBLIC",
+    ],
+    deps = [
+        "fbsource//xplat/hermes/API:HermesAPI",
+        ":chrome",
+        ":inspectorlib",
+    ],
+)
+
+INSPECTOR_EXPORTED_HEADERS = [
+    "AsyncPauseState.h",
+    "Exceptions.h",
+    "Inspector.h",
+    "RuntimeAdapter.h",
+]
+
+# can't be named "inspector" since JSC already uses it, causing a buck rulekey
+# collision: P58794155
+fb_xplat_cxx_library(
+    name = "inspectorlib",
+    srcs = glob(["*.cpp"]),
+    headers = glob(
+        [
+            "*.h",
+        ],
+        exclude = INSPECTOR_EXPORTED_HEADERS,
+    ),
+    header_namespace = "hermes/inspector",
+    exported_headers = INSPECTOR_EXPORTED_HEADERS,
+    compiler_flags = CFLAGS_BY_MODE[hermes_build_mode()],
+    fbobjc_header_path_prefix = "hermes/inspector",
+    macosx_tests_override = [],
+    cxx_tests = [":inspector-tests"],
+    visibility = [
+        "PUBLIC",
+    ],
+    xcode_public_headers_symlinks = True,
+    deps = [
+        "fbsource//xplat/folly:futures",
+        "fbsource//xplat/folly:molly",
+        "fbsource//xplat/hermes/API:HermesAPI",
+        "fbsource//xplat/jsi:jsi",
+        "fbsource//xplat/third-party/glog:glog",
+        ":detail",
+    ],
+)
+
+fb_xplat_cxx_test(
+    name = "inspector-tests",
+    srcs = glob([
+        "tests/*.cpp",
+    ]),
+    headers = glob([
+        "tests/*.h",
+    ]),
+    compiler_flags = CFLAGS_BY_MODE[hermes_build_mode()],
+    platforms = (CXX, APPLE),
+    visibility = [
+        "PUBLIC",
+    ],
+    deps = [
+        "fbsource//xplat/third-party/gmock:gtest",
+        ":inspectorlib",
+    ],
+)

ReactCommon/hermes/inspector/DEFS.bzl

@@ -0,0 +1,7 @@
+load("@fbsource//xplat/hermes/defs:hermes.bzl", "hermes_is_debugger_enabled")
+
+def hermes_inspector_dep_list():
+    return [
+        "fbsource//xplat/hermes-inspector:chrome",
+        "fbsource//xplat/hermes-inspector:inspectorlib",
+    ] if hermes_is_debugger_enabled() else []

ReactCommon/hermes/inspector/Exceptions.h

@@ -0,0 +1,44 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <stdexcept>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+
+class AlreadyEnabledException : public std::runtime_error {
+ public:
+  AlreadyEnabledException()
+      : std::runtime_error("can't enable: debugger already enabled") {}
+};
+
+class NotEnabledException : public std::runtime_error {
+ public:
+  NotEnabledException(const std::string &cmd)
+      : std::runtime_error("debugger can't perform " + cmd + ": not enabled") {}
+};
+
+class InvalidStateException : public std::runtime_error {
+ public:
+  InvalidStateException(
+      const std::string &cmd,
+      const std::string &curState,
+      const std::string &expectedState)
+      : std::runtime_error(
+            "debugger can't perform " + cmd + ": in " + curState +
+            ", expected " + expectedState) {}
+};
+
+class MultipleCommandsPendingException : public std::runtime_error {
+ public:
+  MultipleCommandsPendingException(const std::string &cmd)
+      : std::runtime_error(
+            "debugger can't perform " + cmd +
+            ": a step or resume is already pending") {}
+};
+
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/Inspector.cpp

@@ -0,0 +1,582 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include "Inspector.h"
+#include "Exceptions.h"
+#include "InspectorState.h"
+
+#include <functional>
+#include <string>
+
+#include <glog/logging.h>
+#include <hermes/inspector/detail/SerialExecutor.h>
+#include <hermes/inspector/detail/Thread.h>
+
+// <kludge> This is here, instead of linking against
+// folly/futures/Future.cpp, to avoid pulling in another pile of
+// dependencies, including the separate dependency libevent.  This is
+// likely specific to the version of folly RN uses, so may need to be
+// changed.  Even better, perhaps folly can be refactored to simplify
+// this.
+
+template class folly::Future<folly::Unit>;
+
+namespace folly {
+namespace futures {
+
+Future<Unit> sleep(Duration dur, Timekeeper* tk) {
+  LOG(FATAL) << "folly::futures::sleep() not implemented";
+}
+
+}
+
+namespace detail {
+
+std::shared_ptr<Timekeeper> getTimekeeperSingleton() {
+  LOG(FATAL) << "folly::detail::getTimekeeperSingleton() not implemented";
+}
+
+}
+}
+
+// </kludge>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+
+using folly::Unit;
+
+namespace debugger = ::facebook::hermes::debugger;
+
+/**
+ * Threading notes:
+ *
+ *  1. mutex_ must be held before using state_ or any InspectorState methods.
+ *  2. Methods that are callable by the client (like enable, resume, etc.) call
+ *     various InspectorState methods via state_. This implies that they must
+ *     acquire mutex_.
+ *  3. Since some InspectorState methods call back out to the client (e.g. via
+ *     fulfilling promises, or via the InspectorObserver callbacks), we have to
+ *     be careful about reentrancy from a callback causing a deadlock when (1)
+ *     and (2) interact. Consider:
+ *
+ *       1) Debugger pauses, which causes InspectorObserve::onPause to fire.
+ *          onPause is called by InspectorState::Paused::onEnter on the JS
+ *          thread with mutex_ held.
+ *       2) Client calls setBreakpoint from the onPause callback.
+ *       3) If setBreakpoint directly tried to acquire mutex_ here, we would
+ *          deadlock since our thread already owns the mutex_ (see 1).
+ *
+ * For this reason, all client-facing methods are executed on executor_, which
+ * runs on its own thread. The pattern is:
+ *
+ *  1. The client-facing method foo (e.g. enable) enqueues a call to
+ *      fooOnExecutor (e.g. enableOnExecutor) on executor_.
+ *  2. fooOnExecutor is responsible for acquiring mutex_.
+ *
+ */
+
+// TODO: read this out of an env variable or config
+static constexpr bool kShouldLog = true;
+
+// Logging state transitions is done outside of transition() in a macro so that
+// function and line numbers in the log will be accurate.
+#define TRANSITION(nextState)                                            \
+  do {                                                                   \
+    if (kShouldLog) {                                                    \
+      if (state_ == nullptr) {                                           \
+        LOG(INFO) << "Inspector::" << __func__                           \
+                  << " transitioning to initial state " << *(nextState); \
+      } else {                                                           \
+        LOG(INFO) << "Inspector::" << __func__ << " transitioning from " \
+                  << *state_ << " to " << *(nextState);                  \
+      }                                                                  \
+    }                                                                    \
+    transition((nextState));                                             \
+  } while (0)
+
+Inspector::Inspector(
+    std::shared_ptr<RuntimeAdapter> adapter,
+    InspectorObserver &observer,
+    bool pauseOnFirstStatement)
+    : adapter_(adapter),
+      debugger_(adapter->getRuntime().getDebugger()),
+      observer_(observer),
+      executor_(std::make_unique<detail::SerialExecutor>("hermes-inspector")) {
+  // TODO (t26491391): make tickleJs a real Hermes runtime API
+  const char *src = "function __tickleJs() { return Math.random(); }";
+  adapter->getRuntime().debugJavaScript(src, "__tickleJsHackUrl", {});
+
+  {
+    std::lock_guard<std::mutex> lock(mutex_);
+
+    if (pauseOnFirstStatement) {
+      TRANSITION(std::make_unique<InspectorState::RunningWaitEnable>(*this));
+    } else {
+      TRANSITION(std::make_unique<InspectorState::RunningDetached>(*this));
+    }
+  }
+
+  debugger_.setShouldPauseOnScriptLoad(true);
+  debugger_.setEventObserver(this);
+}
+
+Inspector::~Inspector() {
+  // TODO: think about expected detach flow
+  debugger_.setEventObserver(nullptr);
+}
+
+void Inspector::installConsoleFunction(
+    jsi::Object &console,
+    const std::string &name,
+    const std::string &chromeTypeDefault = "") {
+  jsi::Runtime &rt = adapter_->getRuntime();
+  auto chromeType = chromeTypeDefault == "" ? name : chromeTypeDefault;
+  auto nameID = jsi::PropNameID::forUtf8(rt, name);
+  auto weakInspector = std::weak_ptr<Inspector>(shared_from_this());
+  console.setProperty(
+      rt,
+      nameID,
+      jsi::Function::createFromHostFunction(
+          rt,
+          nameID,
+          1,
+          [weakInspector, chromeType](
+              jsi::Runtime &runtime,
+              const jsi::Value &thisVal,
+              const jsi::Value *args,
+              size_t count) {
+            if (auto inspector = weakInspector.lock()) {
+              jsi::Array argsArray(runtime, count);
+              for (size_t index = 0; index < count; ++index)
+                argsArray.setValueAtIndex(runtime, index, args[index]);
+              inspector->logMessage(
+                  ConsoleMessageInfo{chromeType, std::move(argsArray)});
+            }
+
+            return jsi::Value::undefined();
+          }));
+}
+
+void Inspector::installLogHandler() {
+  jsi::Runtime &rt = adapter_->getRuntime();
+  auto console = jsi::Object(rt);
+  installConsoleFunction(console, "assert");
+  installConsoleFunction(console, "clear");
+  installConsoleFunction(console, "debug");
+  installConsoleFunction(console, "dir");
+  installConsoleFunction(console, "dirxml");
+  installConsoleFunction(console, "error");
+  installConsoleFunction(console, "group", "startGroup");
+  installConsoleFunction(console, "groupCollapsed", "startGroupCollapsed");
+  installConsoleFunction(console, "groupEnd", "endGroup");
+  installConsoleFunction(console, "info");
+  installConsoleFunction(console, "log");
+  installConsoleFunction(console, "profile");
+  installConsoleFunction(console, "profileEnd");
+  installConsoleFunction(console, "table");
+  installConsoleFunction(console, "trace");
+  installConsoleFunction(console, "warn", "warning");
+  rt.global().setProperty(rt, "console", console);
+}
+
+void Inspector::triggerAsyncPause(bool andTickle) {
+  // In order to ensure that we pause soon, we both set the async pause flag on
+  // the runtime, and we run a bit of dummy JS to ensure we enter the Hermes
+  // interpreter loop.
+  debugger_.triggerAsyncPause();
+
+  if (andTickle) {
+    // We run the dummy JS on a background thread to avoid any reentrancy issues
+    // in case this thread is called with the inspector mutex held.
+    std::shared_ptr<RuntimeAdapter> adapter = adapter_;
+    detail::Thread tickleJsLater(
+        "inspectorTickleJs", [adapter]() { adapter->tickleJs(); });
+    tickleJsLater.detach();
+  }
+}
+
+void Inspector::notifyContextCreated() {
+  observer_.onContextCreated(*this);
+}
+
+ScriptInfo Inspector::getScriptInfoFromTopCallFrame() {
+  ScriptInfo info{};
+  auto stackTrace = debugger_.getProgramState().getStackTrace();
+
+  if (stackTrace.callFrameCount() > 0) {
+    uint32_t i = stackTrace.callFrameCount() - 1;
+    debugger::SourceLocation loc = stackTrace.callFrameForIndex(i).location;
+
+    info.fileId = loc.fileId;
+    info.fileName = loc.fileName;
+    info.sourceMappingUrl = debugger_.getSourceMappingUrl(info.fileId);
+  }
+
+  return info;
+}
+
+void Inspector::addCurrentScriptToLoadedScripts() {
+  ScriptInfo info = getScriptInfoFromTopCallFrame();
+
+  if (!loadedScripts_.count(info.fileId)) {
+    loadedScripts_[info.fileId] = LoadedScriptInfo{std::move(info), false};
+  }
+}
+
+void Inspector::removeAllBreakpoints() {
+  debugger_.deleteAllBreakpoints();
+}
+
+void Inspector::resetScriptsLoaded() {
+  for (auto &it : loadedScripts_) {
+    it.second.notifiedClient = false;
+  }
+}
+
+void Inspector::notifyScriptsLoaded() {
+  for (auto &it : loadedScripts_) {
+    LoadedScriptInfo &loadedScriptInfo = it.second;
+
+    if (!loadedScriptInfo.notifiedClient) {
+      loadedScriptInfo.notifiedClient = true;
+      observer_.onScriptParsed(*this, loadedScriptInfo.info);
+    }
+  }
+}
+
+folly::Future<Unit> Inspector::disable() {
+  auto promise = std::make_shared<folly::Promise<Unit>>();
+
+  executor_->add([this, promise] { disableOnExecutor(promise); });
+
+  return promise->getFuture();
+}
+
+folly::Future<Unit> Inspector::enable() {
+  auto promise = std::make_shared<folly::Promise<Unit>>();
+
+  executor_->add([this, promise] { enableOnExecutor(promise); });
+
+  return promise->getFuture();
+}
+
+folly::Future<Unit> Inspector::executeIfEnabled(
+    const std::string &description,
+    folly::Function<void(const debugger::ProgramState &)> func) {
+  auto promise = std::make_shared<folly::Promise<Unit>>();
+
+  executor_->add(
+      [this, description, func = std::move(func), promise]() mutable {
+        executeIfEnabledOnExecutor(description, std::move(func), promise);
+      });
+
+  return promise->getFuture();
+}
+
+folly::Future<debugger::BreakpointInfo> Inspector::setBreakpoint(
+    debugger::SourceLocation loc,
+    folly::Optional<std::string> condition) {
+  auto promise = std::make_shared<folly::Promise<debugger::BreakpointInfo>>();
+
+  executor_->add([this, loc, condition, promise] {
+    setBreakpointOnExecutor(loc, condition, promise);
+  });
+
+  return promise->getFuture();
+}
+
+folly::Future<folly::Unit> Inspector::removeBreakpoint(
+    debugger::BreakpointID breakpointId) {
+  auto promise = std::make_shared<folly::Promise<folly::Unit>>();
+
+  executor_->add([this, breakpointId, promise] {
+    removeBreakpointOnExecutor(breakpointId, promise);
+  });
+
+  return promise->getFuture();
+}
+
+folly::Future<folly::Unit> Inspector::logMessage(ConsoleMessageInfo info) {
+  auto promise = std::make_shared<folly::Promise<folly::Unit>>();
+
+  executor_->add([this,
+                  pInfo = std::make_unique<ConsoleMessageInfo>(std::move(info)),
+                  promise] { logOnExecutor(std::move(*pInfo), promise); });
+
+  return promise->getFuture();
+}
+
+folly::Future<Unit> Inspector::setPendingCommand(debugger::Command command) {
+  auto promise = std::make_shared<folly::Promise<Unit>>();
+
+  executor_->add([this, promise, cmd = std::move(command)]() mutable {
+    setPendingCommandOnExecutor(std::move(cmd), promise);
+  });
+
+  return promise->getFuture();
+}
+
+folly::Future<Unit> Inspector::resume() {
+  return setPendingCommand(debugger::Command::continueExecution());
+}
+
+folly::Future<Unit> Inspector::stepIn() {
+  return setPendingCommand(debugger::Command::step(debugger::StepMode::Into));
+}
+
+folly::Future<Unit> Inspector::stepOver() {
+  return setPendingCommand(debugger::Command::step(debugger::StepMode::Over));
+}
+
+folly::Future<Unit> Inspector::stepOut() {
+  return setPendingCommand(debugger::Command::step(debugger::StepMode::Out));
+}
+
+folly::Future<Unit> Inspector::pause() {
+  auto promise = std::make_shared<folly::Promise<Unit>>();
+
+  executor_->add([this, promise]() { pauseOnExecutor(promise); });
+
+  return promise->getFuture();
+}
+
+folly::Future<debugger::EvalResult> Inspector::evaluate(
+    uint32_t frameIndex,
+    const std::string &src,
+    folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+        resultTransformer) {
+  auto promise = std::make_shared<folly::Promise<debugger::EvalResult>>();
+
+  executor_->add([this,
+                  frameIndex,
+                  src,
+                  promise,
+                  resultTransformer = std::move(resultTransformer)]() mutable {
+    evaluateOnExecutor(frameIndex, src, promise, std::move(resultTransformer));
+  });
+
+  return promise->getFuture();
+}
+
+folly::Future<folly::Unit> Inspector::setPauseOnExceptions(
+    const debugger::PauseOnThrowMode &mode) {
+  auto promise = std::make_shared<folly::Promise<Unit>>();
+
+  executor_->add([this, mode, promise]() mutable {
+    setPauseOnExceptionsOnExecutor(mode, promise);
+  });
+
+  return promise->getFuture();
+};
+
+debugger::Command Inspector::didPause(debugger::Debugger &debugger) {
+  std::unique_lock<std::mutex> lock(mutex_);
+
+  if (kShouldLog) {
+    LOG(INFO) << "received didPause for reason: "
+              << static_cast<int>(debugger.getProgramState().getPauseReason())
+              << " in state: " << *state_;
+  }
+
+  while (true) {
+    /*
+     * Keep sending the onPause event to the current state until we get a
+     * command to return. For instance, this handles the transition from
+     * Running to Paused to Running:
+     *
+     * 1) (R => P) We're currently in Running, so we call Running::didPause,
+     *    which returns {nextState: Paused, command: null}. There isn't a
+     *    command to return yet.
+     * 2) (P => R) Now we're in Paused, so we call Paused::didPause, which
+     *    returns {nextState: Running, command: someCommand} where someCommand
+     *    is non-null (e.g. continue or step over). This terminates the loop.
+     */
+    auto result = state_->didPause(lock);
+
+    std::unique_ptr<InspectorState> nextState = std::move(result.first);
+    if (nextState) {
+      TRANSITION(std::move(nextState));
+    }
+
+    std::unique_ptr<debugger::Command> command = std::move(result.second);
+    if (command) {
+      return std::move(*command);
+    }
+  }
+}
+
+void Inspector::breakpointResolved(
+    debugger::Debugger &debugger,
+    debugger::BreakpointID breakpointId) {
+  std::unique_lock<std::mutex> lock(mutex_);
+
+  debugger::BreakpointInfo info = debugger.getBreakpointInfo(breakpointId);
+  observer_.onBreakpointResolved(*this, info);
+}
+
+void Inspector::transition(std::unique_ptr<InspectorState> nextState) {
+  assert(nextState);
+  assert(state_ != nextState);
+
+  std::unique_ptr<InspectorState> prevState = std::move(state_);
+  state_ = std::move(nextState);
+  state_->onEnter(prevState.get());
+}
+
+void Inspector::disableOnExecutor(
+    std::shared_ptr<folly::Promise<Unit>> promise) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  debugger_.setIsDebuggerAttached(false);
+
+  state_->detach(promise);
+}
+
+void Inspector::enableOnExecutor(
+    std::shared_ptr<folly::Promise<Unit>> promise) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  auto result = state_->enable();
+
+  /**
+   * We fulfill the promise before changing state because fulfilling the promise
+   * responds to the Debugger.enable request, and changing state could send a
+   * notification (like Debugger.paused). It seems like a good idea to respond
+   * to enable before sending out any notifications.
+   */
+  bool enabled = result.second;
+  if (enabled) {
+    debugger_.setIsDebuggerAttached(true);
+    promise->setValue();
+  } else {
+    promise->setException(AlreadyEnabledException());
+  }
+
+  std::unique_ptr<InspectorState> nextState = std::move(result.first);
+  if (nextState) {
+    TRANSITION(std::move(nextState));
+  }
+}
+
+void Inspector::executeIfEnabledOnExecutor(
+    const std::string &description,
+    folly::Function<void(const debugger::ProgramState &)> func,
+    std::shared_ptr<folly::Promise<Unit>> promise) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  if (!state_->isPaused() && !state_->isRunning()) {
+    promise->setException(InvalidStateException(
+        description, state_->description(), "paused or running"));
+    return;
+  }
+
+  folly::Func wrappedFunc = [this, func = std::move(func)]() mutable {
+    func(debugger_.getProgramState());
+  };
+
+  state_->pushPendingFunc(
+      [wrappedFunc = std::move(wrappedFunc), promise]() mutable {
+        wrappedFunc();
+        promise->setValue();
+      });
+}
+
+void Inspector::setBreakpointOnExecutor(
+    debugger::SourceLocation loc,
+    folly::Optional<std::string> condition,
+    std::shared_ptr<folly::Promise<debugger::BreakpointInfo>> promise) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  bool pushed = state_->pushPendingFunc([this, loc, condition, promise] {
+    debugger::BreakpointID id = debugger_.setBreakpoint(loc);
+    debugger::BreakpointInfo info{debugger::kInvalidBreakpoint};
+    if (id != debugger::kInvalidBreakpoint) {
+      info = debugger_.getBreakpointInfo(id);
+
+      if (condition) {
+        debugger_.setBreakpointCondition(id, condition.value());
+      }
+    }
+
+    promise->setValue(std::move(info));
+  });
+
+  if (!pushed) {
+    promise->setException(NotEnabledException("setBreakpoint"));
+  }
+}
+
+void Inspector::removeBreakpointOnExecutor(
+    debugger::BreakpointID breakpointId,
+    std::shared_ptr<folly::Promise<folly::Unit>> promise) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  bool pushed = state_->pushPendingFunc([this, breakpointId, promise] {
+    debugger_.deleteBreakpoint(breakpointId);
+    promise->setValue();
+  });
+
+  if (!pushed) {
+    promise->setException(NotEnabledException("removeBreakpoint"));
+  }
+}
+
+void Inspector::logOnExecutor(
+    ConsoleMessageInfo info,
+    std::shared_ptr<folly::Promise<folly::Unit>> promise) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  state_->pushPendingFunc([this, info = std::move(info)] {
+    observer_.onMessageAdded(*this, info);
+  });
+
+  promise->setValue();
+}
+
+void Inspector::setPendingCommandOnExecutor(
+    debugger::Command command,
+    std::shared_ptr<folly::Promise<Unit>> promise) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  state_->setPendingCommand(std::move(command), promise);
+}
+
+void Inspector::pauseOnExecutor(std::shared_ptr<folly::Promise<Unit>> promise) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  bool canPause = state_->pause();
+
+  if (canPause) {
+    promise->setValue();
+  } else {
+    promise->setException(NotEnabledException("pause"));
+  }
+}
+
+void Inspector::evaluateOnExecutor(
+    uint32_t frameIndex,
+    const std::string &src,
+    std::shared_ptr<folly::Promise<debugger::EvalResult>> promise,
+    folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+        resultTransformer) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  state_->pushPendingEval(
+      frameIndex, src, promise, std::move(resultTransformer));
+}
+
+void Inspector::setPauseOnExceptionsOnExecutor(
+    const debugger::PauseOnThrowMode &mode,
+    std::shared_ptr<folly::Promise<folly::Unit>> promise) {
+  std::lock_guard<std::mutex> local(mutex_);
+
+  state_->pushPendingFunc([this, mode, promise] {
+    debugger_.setPauseOnThrowMode(mode);
+    promise->setValue();
+  });
+}
+
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/Inspector.h

@@ -0,0 +1,306 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <memory>
+#include <queue>
+#include <unordered_map>
+
+#include <folly/Executor.h>
+#include <folly/Unit.h>
+#include <folly/futures/Future.h>
+#include <hermes/DebuggerAPI.h>
+#include <hermes/hermes.h>
+#include <hermes/inspector/AsyncPauseState.h>
+#include <hermes/inspector/RuntimeAdapter.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+
+class Inspector;
+class InspectorState;
+
+/**
+ * ScriptInfo contains info about loaded scripts.
+ */
+struct ScriptInfo {
+  uint32_t fileId{};
+  std::string fileName;
+  std::string sourceMappingUrl;
+};
+
+struct ConsoleMessageInfo {
+  std::string source;
+  std::string level;
+  std::string url;
+  int line;
+  int column;
+
+  jsi::Array args;
+
+  ConsoleMessageInfo(std::string level, jsi::Array args)
+      : source("console-api"),
+        level(level),
+        url(""),
+        line(-1),
+        column(-1),
+        args(std::move(args)) {}
+};
+
+/**
+ * InspectorObserver notifies the observer of events that occur in the VM.
+ */
+class InspectorObserver {
+ public:
+  virtual ~InspectorObserver() = default;
+
+  /// onContextCreated fires when the VM is created.
+  virtual void onContextCreated(Inspector &inspector) = 0;
+
+  /// onBreakpointResolve fires when a lazy breakpoint is resolved.
+  virtual void onBreakpointResolved(
+      Inspector &inspector,
+      const facebook::hermes::debugger::BreakpointInfo &info) = 0;
+
+  /// onPause fires when VM transitions from running to paused state. This is
+  /// called directly on the JS thread while the VM is paused, so the receiver
+  /// can call debugger::ProgramState methods safely.
+  virtual void onPause(
+      Inspector &inspector,
+      const facebook::hermes::debugger::ProgramState &state) = 0;
+
+  /// onResume fires when VM transitions from paused to running state.
+  virtual void onResume(Inspector &inspector) = 0;
+
+  /// onScriptParsed fires when after the VM parses a script.
+  virtual void onScriptParsed(Inspector &inspector, const ScriptInfo &info) = 0;
+
+  // onMessageAdded fires when new console message is added.
+  virtual void onMessageAdded(
+      Inspector &inspector,
+      const ConsoleMessageInfo &info) = 0;
+};
+
+/**
+ * Inspector implements a future-based interface over the low-level Hermes
+ * debugging API.
+ */
+class Inspector : public facebook::hermes::debugger::EventObserver,
+                  public std::enable_shared_from_this<Inspector> {
+ public:
+  /**
+   * Inspector's constructor should be used to install the inspector on the
+   * provided runtime before any JS executes in the runtime.
+   */
+  Inspector(
+      std::shared_ptr<RuntimeAdapter> adapter,
+      InspectorObserver &observer,
+      bool pauseOnFirstStatement);
+  ~Inspector();
+
+  /**
+   * disable turns off the inspector. All of the subsequent methods will not do
+   * anything unless the inspector is enabled.
+   */
+  folly::Future<folly::Unit> disable();
+
+  /**
+   * enable turns on the inspector. All of the subsequent methods will not do
+   * anything unless the inspector is enabled. The returned future succeeds when
+   * the debugger is enabled, or fails with AlreadyEnabledException if the
+   * debugger was already enabled.
+   */
+  folly::Future<folly::Unit> enable();
+
+  /**
+   * installs console log handler. Ideally this should be done inside
+   * constructor, but because it uses shared_from_this we can't do this
+   * in constructor.
+   */
+  void installLogHandler();
+
+  /**
+   * executeIfEnabled executes the provided callback *on the JS thread with the
+   * inspector lock held*. Execution can be implicitly requested while running.
+   * The inspector lock:
+   *
+   *  1) Protects VM state transitions. This means that the VM is guaranteed to
+   *     stay in the paused or running state for the duration of the callback.
+   *  2) Protects InspectorObserver callbacks. This means that if some shared
+   *     data is accessed only in InspectorObserver and executeIfEnabled
+   *     callbacks, it does not need to be locked, since it's already protected
+   *     by the inspector lock.
+   *
+   * The returned future resolves to true in the VM can be paused, or
+   * fails with IllegalStateException otherwise. The description is only used
+   * to populate the IllegalStateException with more useful info on failure.
+   */
+  folly::Future<folly::Unit> executeIfEnabled(
+      const std::string &description,
+      folly::Function<void(const facebook::hermes::debugger::ProgramState &)>
+          func);
+
+  /**
+   * setBreakpoint can be called at any time after the debugger is enabled to
+   * set a breakpoint in the VM. The future is fulfilled with the resolved
+   * breakpoint info.
+   *
+   * Resolving a breakpoint takes an indeterminate amount of time since Hermes
+   * only resolves breakpoints when the debugger is able to actively pause JS
+   * execution.
+   */
+  folly::Future<facebook::hermes::debugger::BreakpointInfo> setBreakpoint(
+      facebook::hermes::debugger::SourceLocation loc,
+      folly::Optional<std::string> condition = folly::none);
+
+  folly::Future<folly::Unit> removeBreakpoint(
+      facebook::hermes::debugger::BreakpointID loc);
+
+  /**
+   * logs console message.
+   */
+  folly::Future<folly::Unit> logMessage(ConsoleMessageInfo info);
+
+  /**
+   * resume and step methods are only valid when the VM is currently paused. The
+   * returned future suceeds when the VM resumes execution, or fails with an
+   * InvalidStateException otherwise.
+   */
+  folly::Future<folly::Unit> resume();
+  folly::Future<folly::Unit> stepIn();
+  folly::Future<folly::Unit> stepOver();
+  folly::Future<folly::Unit> stepOut();
+
+  /**
+   * pause can be issued at any time while the inspector is enabled. It requests
+   * the VM to asynchronously break execution. The returned future suceeds if
+   * the VM can be paused in this state and fails with InvalidStateException if
+   * otherwise.
+   */
+  folly::Future<folly::Unit> pause();
+
+  /**
+   * evaluate runs JavaScript code within the context of a call frame. The
+   * returned promise is fulfilled with an eval result if it's possible to
+   * evaluate code in the current state or fails with InvalidStateException
+   * otherwise.
+   */
+  folly::Future<facebook::hermes::debugger::EvalResult> evaluate(
+      uint32_t frameIndex,
+      const std::string &src,
+      folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+          resultTransformer);
+
+  folly::Future<folly::Unit> setPauseOnExceptions(
+      const facebook::hermes::debugger::PauseOnThrowMode &mode);
+
+  /**
+   * didPause implements the pause callback from Hermes. This callback arrives
+   * on the JS thread.
+   */
+  facebook::hermes::debugger::Command didPause(
+      facebook::hermes::debugger::Debugger &debugger) override;
+
+  /**
+   * breakpointResolved implements the breakpointResolved callback from Hermes.
+   */
+  void breakpointResolved(
+      facebook::hermes::debugger::Debugger &debugger,
+      facebook::hermes::debugger::BreakpointID breakpointId) override;
+
+ private:
+  friend class InspectorState;
+
+  void triggerAsyncPause(bool andTickle);
+
+  void notifyContextCreated();
+
+  ScriptInfo getScriptInfoFromTopCallFrame();
+
+  void addCurrentScriptToLoadedScripts();
+  void removeAllBreakpoints();
+  void resetScriptsLoaded();
+  void notifyScriptsLoaded();
+
+  folly::Future<folly::Unit> setPendingCommand(debugger::Command command);
+
+  void transition(std::unique_ptr<InspectorState> nextState);
+
+  // All methods that end with OnExecutor run on executor_.
+  void disableOnExecutor(std::shared_ptr<folly::Promise<folly::Unit>> promise);
+
+  void enableOnExecutor(std::shared_ptr<folly::Promise<folly::Unit>> promise);
+
+  void executeIfEnabledOnExecutor(
+      const std::string &description,
+      folly::Function<void(const facebook::hermes::debugger::ProgramState &)>
+          func,
+      std::shared_ptr<folly::Promise<folly::Unit>> promise);
+
+  void setBreakpointOnExecutor(
+      debugger::SourceLocation loc,
+      folly::Optional<std::string> condition,
+      std::shared_ptr<
+          folly::Promise<facebook::hermes::debugger::BreakpointInfo>> promise);
+
+  void removeBreakpointOnExecutor(
+      debugger::BreakpointID breakpointId,
+      std::shared_ptr<folly::Promise<folly::Unit>> promise);
+
+  void logOnExecutor(
+      ConsoleMessageInfo info,
+      std::shared_ptr<folly::Promise<folly::Unit>> promise);
+
+  void setPendingCommandOnExecutor(
+      facebook::hermes::debugger::Command command,
+      std::shared_ptr<folly::Promise<folly::Unit>> promise);
+
+  void pauseOnExecutor(std::shared_ptr<folly::Promise<folly::Unit>> promise);
+
+  void evaluateOnExecutor(
+      uint32_t frameIndex,
+      const std::string &src,
+      std::shared_ptr<folly::Promise<facebook::hermes::debugger::EvalResult>>
+          promise,
+      folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+          resultTransformer);
+
+  void setPauseOnExceptionsOnExecutor(
+      const facebook::hermes::debugger::PauseOnThrowMode &mode,
+      std::shared_ptr<folly::Promise<folly::Unit>> promise);
+
+  void installConsoleFunction(
+      jsi::Object &console,
+      const std::string &name,
+      const std::string &chromeType);
+
+  std::shared_ptr<RuntimeAdapter> adapter_;
+  facebook::hermes::debugger::Debugger &debugger_;
+  InspectorObserver &observer_;
+
+  // All client methods (e.g. enable, setBreakpoint, resume, etc.) are executed
+  // on executor_ to prevent deadlocking on mutex_. See the implementation for
+  // more comments on the threading invariants used in this class.
+  std::unique_ptr<folly::Executor> executor_;
+
+  // All of the following member variables are guarded by mutex_.
+  std::mutex mutex_;
+  std::unique_ptr<InspectorState> state_;
+
+  // See the InspectorState::Running implementation for an explanation for why
+  // this state is here rather than in the Running class.
+  AsyncPauseState pendingPauseState_ = AsyncPauseState::None;
+
+  // All scripts loaded in to the VM, along with whether we've notified the
+  // client about the script yet.
+  struct LoadedScriptInfo {
+    ScriptInfo info;
+    bool notifiedClient;
+  };
+  std::unordered_map<int, LoadedScriptInfo> loadedScripts_;
+};
+
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/InspectorState.cpp

@@ -0,0 +1,476 @@
+#include "InspectorState.h"
+
+#include <glog/logging.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+
+using folly::Unit;
+
+namespace debugger = ::facebook::hermes::debugger;
+
+namespace {
+
+std::unique_ptr<debugger::Command> makeContinueCommand() {
+  return std::make_unique<debugger::Command>(
+      debugger::Command::continueExecution());
+}
+
+} // namespace
+
+std::ostream &operator<<(std::ostream &os, const InspectorState &state) {
+  return os << state.description();
+}
+
+/*
+ * InspectorState::RunningDetached
+ */
+
+std::pair<NextStatePtr, CommandPtr> InspectorState::RunningDetached::didPause(
+    MonitorLock &lock) {
+  debugger::PauseReason reason = getPauseReason();
+
+  if (reason == debugger::PauseReason::DebuggerStatement) {
+    return std::make_pair<NextStatePtr, CommandPtr>(
+        InspectorState::PausedWaitEnable::make(inspector_), nullptr);
+  }
+
+  if (reason == debugger::PauseReason::ScriptLoaded) {
+    inspector_.addCurrentScriptToLoadedScripts();
+  }
+
+  return std::make_pair<NextStatePtr, CommandPtr>(
+      nullptr, makeContinueCommand());
+}
+
+std::pair<NextStatePtr, bool> InspectorState::RunningDetached::enable() {
+  return std::make_pair<NextStatePtr, bool>(
+      InspectorState::Running::make(inspector_), true);
+}
+
+/*
+ * InspectorState::RunningWaitEnable
+ */
+
+std::pair<NextStatePtr, CommandPtr> InspectorState::RunningWaitEnable::didPause(
+    MonitorLock &lock) {
+  // If we started in RWE, then we asked for the VM to break on the first
+  // statement, and the first pause should be because of a script load.
+  assert(getPauseReason() == debugger::PauseReason::ScriptLoaded);
+  inspector_.addCurrentScriptToLoadedScripts();
+
+  return std::make_pair<NextStatePtr, CommandPtr>(
+      InspectorState::PausedWaitEnable::make(inspector_), nullptr);
+}
+
+std::pair<NextStatePtr, bool> InspectorState::RunningWaitEnable::enable() {
+  return std::make_pair<NextStatePtr, bool>(
+      InspectorState::RunningWaitPause::make(inspector_), true);
+}
+
+/*
+ * InspectorState::RunningWaitPause
+ */
+std::pair<NextStatePtr, CommandPtr> InspectorState::RunningWaitPause::didPause(
+    MonitorLock &lock) {
+  // If we are in RWP, then we asked for the VM to break on the first
+  // statement, and the first pause should be because of a script load.
+  assert(getPauseReason() == debugger::PauseReason::ScriptLoaded);
+  inspector_.addCurrentScriptToLoadedScripts();
+
+  return std::make_pair<NextStatePtr, CommandPtr>(
+      InspectorState::Paused::make(inspector_), nullptr);
+}
+
+/*
+ * InspectorState::PausedWaitEnable
+ */
+
+std::pair<NextStatePtr, CommandPtr> InspectorState::PausedWaitEnable::didPause(
+    MonitorLock &lock) {
+  if (getPauseReason() == debugger::PauseReason::ScriptLoaded) {
+    inspector_.addCurrentScriptToLoadedScripts();
+  }
+
+  while (!enabled_) {
+    /*
+     * The call to wait temporarily relinquishes the inspector mutex. This is
+     * safe because no other PausedWaitEnable event handler directly transitions
+     * out of PausedWaitEnable. So we know that our state is the active state
+     * both before and after the call to wait. This preserves the invariant that
+     * the inspector state is not modified during the execution of this method.
+     *
+     * Instead, PausedWaitEnable::enable indirectly induces the state transition
+     * out of PausedWaitEnable by signaling us via enabledCondition_.
+     */
+    enabledCondition_.wait(lock);
+
+    assert(inspector_.state_.get() == this);
+  }
+
+  return std::make_pair<NextStatePtr, CommandPtr>(
+      InspectorState::Paused::make(inspector_), nullptr);
+}
+
+std::pair<NextStatePtr, bool> InspectorState::PausedWaitEnable::enable() {
+  if (enabled_) {
+    // Someone already called enable before and we're just waiting for the
+    // condition variable to wake up didPause.
+    return std::make_pair<NextStatePtr, bool>(nullptr, false);
+  }
+
+  enabled_ = true;
+  enabledCondition_.notify_one();
+  return std::make_pair<NextStatePtr, bool>(nullptr, true);
+}
+
+/*
+ * InspectorState::Running
+ *
+ * # Async Pauses
+ *
+ * We distinguish between implicit and explicit async pauses. An implicit async
+ * pause is requested by the inspector itself to service a request that requires
+ * the VM to be paused (e.g. to set a breakpoint). This is different from an
+ * explicit async pause requested by the user by hitting the pause button in the
+ * debugger UI.
+ *
+ * The async pause state must live in the Inspector class instead of the Running
+ * class because of potential races between when the implicit pause is requested
+ * and when it's serviced. Consider:
+ *
+ *  1. We request an implicit pause (e.g. to set a breakpoint).
+ *  2. An existing breakpoint fires, moving us from Running => Paused.
+ *  3. Client resumes execution, moving us from Paused => Running.
+ *  4. Now the debugger notices the async pause flag we set in (1), which pauses
+ *     us again, causing Running::didPause to run.
+ *
+ * In this case, the Running state instance from (1) is no longer the same as
+ * the Running state instance in (4). But the running state instance in (4)
+ * needs to know that we requested the async break sometime in the past so it
+ * knows to automatically continue in the didPause callback. Therefore the async
+ * break state has to be stored in the long-lived Inspector class rather than in
+ * the short-lived Running class.
+ */
+
+void InspectorState::Running::onEnter(InspectorState *prevState) {
+  if (prevState) {
+    if (prevState->isPaused()) {
+      inspector_.observer_.onResume(inspector_);
+    } else {
+      // send context created and script load notifications if we just enabled
+      // the debugger
+      inspector_.notifyContextCreated();
+      inspector_.notifyScriptsLoaded();
+    }
+  }
+}
+
+void InspectorState::Running::detach(
+    std::shared_ptr<folly::Promise<Unit>> promise) {
+  pushPendingFunc([this, promise] {
+    pendingDetach_ = promise;
+
+    inspector_.removeAllBreakpoints();
+    inspector_.resetScriptsLoaded();
+  });
+}
+
+std::pair<NextStatePtr, CommandPtr> InspectorState::Running::didPause(
+    MonitorLock &lock) {
+  debugger::PauseReason reason = getPauseReason();
+
+  for (auto &func : pendingFuncs_) {
+    func();
+  }
+  pendingFuncs_.clear();
+
+  if (pendingDetach_) {
+    // Clear any pending pause state back to no requests for the next attach
+    inspector_.pendingPauseState_ = AsyncPauseState::None;
+
+    // Ensure we fulfill any pending ScriptLoaded requests
+    if (reason == debugger::PauseReason::ScriptLoaded) {
+      inspector_.addCurrentScriptToLoadedScripts();
+    }
+
+    // Fail any in-flight Eval requests
+    if (pendingEvalPromise_) {
+      pendingEvalPromise_->setException(NotEnabledException("eval"));
+    }
+
+    // if we requested the break implicitly to clear state and detach,
+    // transition to RunningDetached
+    pendingDetach_->setValue();
+
+    return std::make_pair<NextStatePtr, CommandPtr>(
+        InspectorState::RunningDetached::make(inspector_),
+        makeContinueCommand());
+  }
+
+  if (reason == debugger::PauseReason::AsyncTrigger) {
+    AsyncPauseState &pendingPauseState = inspector_.pendingPauseState_;
+
+    switch (pendingPauseState) {
+      case AsyncPauseState::None:
+        // shouldn't ever async break without us asking first
+        assert(false);
+        break;
+      case AsyncPauseState::Implicit:
+        pendingPauseState = AsyncPauseState::None;
+        break;
+      case AsyncPauseState::Explicit:
+        // explicit break was requested by user, so go to Paused state
+        pendingPauseState = AsyncPauseState::None;
+        return std::make_pair<NextStatePtr, CommandPtr>(
+            InspectorState::Paused::make(inspector_), nullptr);
+    }
+  } else if (reason == debugger::PauseReason::ScriptLoaded) {
+    inspector_.addCurrentScriptToLoadedScripts();
+    inspector_.notifyScriptsLoaded();
+  } else if (reason == debugger::PauseReason::EvalComplete) {
+    assert(pendingEvalPromise_);
+
+    pendingEvalResultTransformer_(
+        inspector_.debugger_.getProgramState().getEvalResult());
+    pendingEvalPromise_->setValue(
+        inspector_.debugger_.getProgramState().getEvalResult());
+    pendingEvalPromise_.reset();
+  } else /* other cases imply a transition to Pause */ {
+    return std::make_pair<NextStatePtr, CommandPtr>(
+        InspectorState::Paused::make(inspector_), nullptr);
+  }
+
+  if (!pendingEvals_.empty()) {
+    assert(!pendingEvalPromise_);
+
+    auto eval = std::make_unique<PendingEval>(std::move(pendingEvals_.front()));
+    pendingEvals_.pop();
+
+    pendingEvalPromise_ = eval->promise;
+    pendingEvalResultTransformer_ = std::move(eval->resultTransformer);
+
+    return std::make_pair<NextStatePtr, CommandPtr>(
+        nullptr, std::make_unique<debugger::Command>(std::move(eval->command)));
+  }
+
+  return std::make_pair<NextStatePtr, CommandPtr>(
+      nullptr, makeContinueCommand());
+}
+
+bool InspectorState::Running::pushPendingFunc(folly::Func func) {
+  pendingFuncs_.emplace_back(std::move(func));
+
+  if (inspector_.pendingPauseState_ == AsyncPauseState::None) {
+    inspector_.pendingPauseState_ = AsyncPauseState::Implicit;
+    inspector_.triggerAsyncPause(true);
+  }
+
+  return true;
+}
+
+void InspectorState::Running::pushPendingEval(
+    uint32_t frameIndex,
+    const std::string &src,
+    std::shared_ptr<folly::Promise<debugger::EvalResult>> promise,
+    folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+        resultTransformer) {
+  PendingEval pendingEval{debugger::Command::eval(src, frameIndex),
+                          promise,
+                          std::move(resultTransformer)};
+
+  pendingEvals_.emplace(std::move(pendingEval));
+
+  if (inspector_.pendingPauseState_ == AsyncPauseState::None) {
+    inspector_.pendingPauseState_ = AsyncPauseState::Implicit;
+  }
+
+  inspector_.triggerAsyncPause(true);
+}
+
+bool InspectorState::Running::pause() {
+  AsyncPauseState &pendingPauseState = inspector_.pendingPauseState_;
+  bool canPause = false;
+
+  switch (pendingPauseState) {
+    case AsyncPauseState::None:
+      // haven't yet requested a pause, so do it now
+      inspector_.triggerAsyncPause(false);
+      pendingPauseState = AsyncPauseState::Explicit;
+      canPause = true;
+      break;
+    case AsyncPauseState::Implicit:
+      // already requested an implicit pause on our own, upgrade it to an
+      // explicit pause
+      pendingPauseState = AsyncPauseState::Explicit;
+      canPause = true;
+      break;
+    case AsyncPauseState::Explicit:
+      // client already requested a pause that hasn't occurred yet
+      canPause = false;
+      break;
+  }
+
+  return canPause;
+}
+
+/*
+ * InspectorState::Paused
+ */
+
+void InspectorState::Paused::onEnter(InspectorState *prevState) {
+  // send script load notifications if we just enabled the debugger
+  if (prevState && !prevState->isRunning()) {
+    inspector_.notifyContextCreated();
+    inspector_.notifyScriptsLoaded();
+  }
+
+  const debugger::ProgramState &state = inspector_.debugger_.getProgramState();
+  inspector_.observer_.onPause(inspector_, state);
+}
+
+std::pair<NextStatePtr, CommandPtr> InspectorState::Paused::didPause(
+    std::unique_lock<std::mutex> &lock) {
+  switch (getPauseReason()) {
+    case debugger::PauseReason::AsyncTrigger:
+      inspector_.pendingPauseState_ = AsyncPauseState::None;
+      break;
+    case debugger::PauseReason::EvalComplete: {
+      assert(pendingEvalPromise_);
+      pendingEvalResultTransformer_(
+          inspector_.debugger_.getProgramState().getEvalResult());
+      pendingEvalPromise_->setValue(
+          inspector_.debugger_.getProgramState().getEvalResult());
+      pendingEvalPromise_.reset();
+    } break;
+    case debugger::PauseReason::ScriptLoaded:
+      inspector_.addCurrentScriptToLoadedScripts();
+      inspector_.notifyScriptsLoaded();
+      break;
+    default:
+      break;
+  }
+
+  std::unique_ptr<PendingEval> eval;
+  std::unique_ptr<PendingCommand> resumeOrStep;
+
+  while (!eval && !resumeOrStep && !pendingDetach_) {
+    {
+      while (!pendingCommand_ && pendingEvals_.empty() &&
+             pendingFuncs_.empty()) {
+        /*
+         * The call to wait temporarily relinquishes the inspector mutex. This
+         * is safe because no other Paused event handler directly transitions
+         * out of Paused. So we know that our state is the active state both
+         * before and after the call to wait. This preserves the invariant that
+         * the inspector state is not modified during the execution of this
+         * method.
+         */
+        hasPendingWork_.wait(lock);
+      }
+
+      assert(inspector_.state_.get() == this);
+    }
+
+    if (!pendingEvals_.empty()) {
+      eval = std::make_unique<PendingEval>(std::move(pendingEvals_.front()));
+      pendingEvals_.pop();
+    } else if (pendingCommand_) {
+      resumeOrStep.swap(pendingCommand_);
+    }
+
+    for (auto &func : pendingFuncs_) {
+      func();
+    }
+    pendingFuncs_.clear();
+  }
+
+  if (pendingDetach_) {
+    if (pendingEvalPromise_) {
+      pendingEvalPromise_->setException(NotEnabledException("eval"));
+    }
+
+    if (resumeOrStep) {
+      resumeOrStep->promise->setValue();
+    }
+
+    pendingDetach_->setValue();
+
+    // Send resume so client-side UI doesn't stay stuck at the breakpoint UI
+    inspector_.observer_.onResume(inspector_);
+
+    return std::make_pair<NextStatePtr, CommandPtr>(
+        InspectorState::RunningDetached::make(inspector_),
+        makeContinueCommand());
+  }
+
+  if (eval) {
+    assert(!pendingEvalPromise_);
+    pendingEvalPromise_ = eval->promise;
+    pendingEvalResultTransformer_ = std::move(eval->resultTransformer);
+
+    return std::make_pair<NextStatePtr, CommandPtr>(
+        nullptr, std::make_unique<debugger::Command>(std::move(eval->command)));
+  }
+
+  assert(resumeOrStep);
+  resumeOrStep->promise->setValue();
+
+  return std::make_pair<NextStatePtr, CommandPtr>(
+      InspectorState::Running::make(inspector_),
+      std::make_unique<debugger::Command>(std::move(resumeOrStep->command)));
+}
+
+void InspectorState::Paused::detach(
+    std::shared_ptr<folly::Promise<Unit>> promise) {
+  pushPendingFunc([this, promise] {
+    pendingDetach_ = promise;
+
+    inspector_.removeAllBreakpoints();
+    inspector_.resetScriptsLoaded();
+  });
+}
+
+bool InspectorState::Paused::pushPendingFunc(folly::Func func) {
+  pendingFuncs_.emplace_back(std::move(func));
+  hasPendingWork_.notify_one();
+
+  return true;
+}
+
+void InspectorState::Paused::pushPendingEval(
+    uint32_t frameIndex,
+    const std::string &src,
+    std::shared_ptr<folly::Promise<debugger::EvalResult>> promise,
+    folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+        resultTransformer) {
+  // Shouldn't allow the client to eval if there's already a pending resume/step
+  if (pendingCommand_) {
+    promise->setException(MultipleCommandsPendingException("eval"));
+    return;
+  }
+
+  PendingEval pendingEval{debugger::Command::eval(src, frameIndex),
+                          promise,
+                          std::move(resultTransformer)};
+  pendingEvals_.emplace(std::move(pendingEval));
+  hasPendingWork_.notify_one();
+}
+
+void InspectorState::Paused::setPendingCommand(
+    debugger::Command command,
+    std::shared_ptr<folly::Promise<Unit>> promise) {
+  if (pendingCommand_) {
+    promise->setException(MultipleCommandsPendingException("cmd"));
+    return;
+  }
+
+  pendingCommand_ =
+      std::make_unique<PendingCommand>(std::move(command), promise);
+  hasPendingWork_.notify_one();
+}
+
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/InspectorState.h

@@ -0,0 +1,400 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <condition_variable>
+#include <iostream>
+#include <memory>
+#include <mutex>
+#include <queue>
+#include <utility>
+
+#include <folly/Unit.h>
+#include <hermes/inspector/Exceptions.h>
+#include <hermes/inspector/Inspector.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+
+using NextStatePtr = std::unique_ptr<InspectorState>;
+using CommandPtr = std::unique_ptr<facebook::hermes::debugger::Command>;
+using MonitorLock = std::unique_lock<std::mutex>;
+
+/**
+ * InspectorState encapsulates a single state in the Inspector FSM. Events in
+ * the FSM are modeled as methods in InspectorState.
+ *
+ * Some events may cause state transitions. The next state is returned via a
+ * pointer to the next InspectorState.
+ *
+ * We assume that the Inspector's mutex is held across all calls to
+ * InspectorState methods. For more threading notes, see the Inspector
+ * implementation.
+ */
+class InspectorState {
+ public:
+  InspectorState(Inspector &inspector) : inspector_(inspector) {}
+  virtual ~InspectorState() = default;
+  /**
+   * onEnter is called when entering the state. prevState may be null when
+   * transitioning into an initial state.
+   */
+  virtual void onEnter(InspectorState *prevState) {}
+
+  /*
+   * Events that may cause a state transition.
+   */
+
+  /**
+   * detach clears all debuger state and transitions to RunningDetached.
+   */
+  virtual void detach(std::shared_ptr<folly::Promise<folly::Unit>> promise) {
+    // As we're not attached we'd like for the operation to be idempotent
+    promise->setValue();
+  }
+
+  /**
+   * didPause handles the didPause callback from the debugger. It takes the lock
+   * associated with the Inspector's mutex by reference in case we need to
+   * temporarily relinquish the lock (e.g. via condition_variable::wait).
+   */
+  virtual std::pair<NextStatePtr, CommandPtr> didPause(MonitorLock &lock) = 0;
+
+  /**
+   * enable handles the enable event from the client.
+   */
+  virtual std::pair<NextStatePtr, bool> enable() {
+    return std::make_pair<NextStatePtr, bool>(nullptr, false);
+  }
+
+  /*
+   * Events that don't cause a state transition.
+   */
+
+  /**
+   * pushPendingFunc appends a function to run the next time the debugger
+   * pauses, either explicitly while paused or implicitly while running.
+   * Returns false if it's not possible to push a func in this state.
+   */
+  virtual bool pushPendingFunc(folly::Func func) {
+    return false;
+  }
+
+  /**
+   * pushPendingEval appends an eval request to run the next time the debugger
+   * pauses, either explicitly while paused or implicitly while running.
+   * resultTransformer function will be called with EvalResult before returning
+   * result so that we can manipulate EvalResult while the VM is paused.
+   */
+  virtual void pushPendingEval(
+      uint32_t frameIndex,
+      const std::string &src,
+      std::shared_ptr<folly::Promise<facebook::hermes::debugger::EvalResult>>
+          promise,
+      folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+          resultTransformer) {
+    promise->setException(
+        InvalidStateException("eval", description(), "paused or running"));
+  }
+
+  /**
+   * setPendingCommand sets a command to break the debugger out of the didPause
+   * run loop. If it's not possible to set a pending command in this state, the
+   * promise fails with InvalidStateException. Otherwise, the promise resolves
+   * to true when the command actually executes.
+   */
+  virtual void setPendingCommand(
+      debugger::Command command,
+      std::shared_ptr<folly::Promise<folly::Unit>> promise) {
+    promise->setException(
+        InvalidStateException("cmd", description(), "paused"));
+  }
+
+  /**
+   * pause requests an async pause from the VM.
+   */
+  virtual bool pause() {
+    return false;
+  }
+
+  /*
+   * Convenience functions for determining the concrete type and description
+   * for a state instance without RTTI.
+   */
+
+  virtual bool isRunningDetached() const {
+    return false;
+  }
+  virtual bool isRunningWaitEnable() const {
+    return false;
+  }
+  virtual bool isRunningWaitPause() const {
+    return false;
+  }
+  virtual bool isPausedWaitEnable() const {
+    return false;
+  }
+  virtual bool isRunning() const {
+    return false;
+  }
+  virtual bool isPaused() const {
+    return false;
+  }
+
+  virtual const char *description() const = 0;
+  friend std::ostream &operator<<(
+      std::ostream &os,
+      const InspectorState &state);
+
+  class RunningDetached;
+  class RunningWaitEnable;
+  class RunningWaitPause;
+  class PausedWaitEnable;
+  class Running;
+  class Paused;
+
+ protected:
+  debugger::PauseReason getPauseReason() {
+    return inspector_.debugger_.getProgramState().getPauseReason();
+  }
+
+ private:
+  Inspector &inspector_;
+};
+
+extern std::ostream &operator<<(std::ostream &os, const InspectorState &state);
+
+/**
+ * RunningDetached is the initial state when we're associated with a VM that
+ * initially has no breakpoints.
+ */
+class InspectorState::RunningDetached : public InspectorState {
+ public:
+  static std::unique_ptr<InspectorState> make(Inspector &inspector) {
+    return std::make_unique<RunningDetached>(inspector);
+  }
+
+  RunningDetached(Inspector &inspector) : InspectorState(inspector) {}
+  ~RunningDetached() {}
+
+  std::pair<NextStatePtr, CommandPtr> didPause(MonitorLock &lock) override;
+  std::pair<NextStatePtr, bool> enable() override;
+
+  bool isRunningDetached() const override {
+    return true;
+  }
+
+  const char *description() const override {
+    return "RunningDetached";
+  }
+};
+
+/**
+ * RunningWaitEnable is the initial state when we're associated with a VM that
+ * has a breakpoint on the first statement.
+ */
+class InspectorState::RunningWaitEnable : public InspectorState {
+ public:
+  static std::unique_ptr<InspectorState> make(Inspector &inspector) {
+    return std::make_unique<RunningWaitEnable>(inspector);
+  }
+
+  RunningWaitEnable(Inspector &inspector) : InspectorState(inspector) {}
+  ~RunningWaitEnable() {}
+
+  std::pair<NextStatePtr, CommandPtr> didPause(MonitorLock &lock) override;
+  std::pair<NextStatePtr, bool> enable() override;
+
+  bool isRunningWaitEnable() const override {
+    return true;
+  }
+
+  const char *description() const override {
+    return "RunningWaitEnable";
+  }
+};
+
+/**
+ * RunningWaitPause is the state when we've received enable call, but
+ * waiting for didPause because we need to pause on the first statement.
+ */
+class InspectorState::RunningWaitPause : public InspectorState {
+ public:
+  static std::unique_ptr<InspectorState> make(Inspector &inspector) {
+    return std::make_unique<RunningWaitPause>(inspector);
+  }
+
+  std::pair<NextStatePtr, CommandPtr> didPause(MonitorLock &lock) override;
+
+  RunningWaitPause(Inspector &inspector) : InspectorState(inspector) {}
+  ~RunningWaitPause() {}
+
+  bool isRunningWaitPause() const override {
+    return true;
+  }
+
+  const char *description() const override {
+    return "RunningWaitPause";
+  }
+};
+
+/**
+ * PausedWaitEnable is the state when we're in a didPause callback and we're
+ * waiting for the client to call enable.
+ */
+class InspectorState::PausedWaitEnable : public InspectorState {
+ public:
+  static std::unique_ptr<InspectorState> make(Inspector &inspector) {
+    return std::make_unique<PausedWaitEnable>(inspector);
+  }
+
+  PausedWaitEnable(Inspector &inspector) : InspectorState(inspector) {}
+  ~PausedWaitEnable() {}
+
+  std::pair<NextStatePtr, CommandPtr> didPause(MonitorLock &lock) override;
+  std::pair<NextStatePtr, bool> enable() override;
+
+  bool isPausedWaitEnable() const override {
+    return true;
+  }
+
+  const char *description() const override {
+    return "PausedWaitEnable";
+  }
+
+ private:
+  bool enabled_ = false;
+  std::condition_variable enabledCondition_;
+};
+
+/**
+ * PendingEval holds an eval command and a promise that is fulfilled with the
+ * eval result.
+ */
+struct PendingEval {
+  debugger::Command command;
+  std::shared_ptr<folly::Promise<facebook::hermes::debugger::EvalResult>>
+      promise;
+  folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+      resultTransformer;
+};
+
+/**
+ * Running is the state when we're enabled and not currently paused, e.g. when
+ * we're actively executing JS.
+ *
+ * Note that we can be in the running state even if we're not actively running
+ * JS. For instance, React Native could be blocked in a native message queue
+ * waiting for the next message to process outside of the call in to Hermes.
+ * That still counts as Running in this FSM.
+ */
+class InspectorState::Running : public InspectorState {
+ public:
+  static std::unique_ptr<InspectorState> make(Inspector &inspector) {
+    return std::make_unique<Running>(inspector);
+  }
+
+  Running(Inspector &inspector) : InspectorState(inspector) {}
+  ~Running() {}
+
+  void onEnter(InspectorState *prevState) override;
+
+  void detach(std::shared_ptr<folly::Promise<folly::Unit>> promise) override;
+
+  std::pair<NextStatePtr, CommandPtr> didPause(MonitorLock &lock) override;
+  bool pushPendingFunc(folly::Func func) override;
+  void pushPendingEval(
+      uint32_t frameIndex,
+      const std::string &src,
+      std::shared_ptr<folly::Promise<facebook::hermes::debugger::EvalResult>>
+          promise,
+      folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+          resultTransformer) override;
+  bool pause() override;
+
+  bool isRunning() const override {
+    return true;
+  }
+
+  const char *description() const override {
+    return "Running";
+  }
+
+ private:
+  std::vector<folly::Func> pendingFuncs_;
+  std::queue<PendingEval> pendingEvals_;
+  std::shared_ptr<folly::Promise<facebook::hermes::debugger::EvalResult>>
+      pendingEvalPromise_;
+  folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+      pendingEvalResultTransformer_;
+  std::shared_ptr<folly::Promise<folly::Unit>> pendingDetach_;
+};
+
+/**
+ * PendingCommand holds a resume or step command and a promise that is fulfilled
+ * just before the debugger resumes or steps.
+ */
+struct PendingCommand {
+  PendingCommand(
+      debugger::Command command,
+      std::shared_ptr<folly::Promise<folly::Unit>> promise)
+      : command(std::move(command)), promise(promise) {}
+
+  debugger::Command command;
+  std::shared_ptr<folly::Promise<folly::Unit>> promise;
+};
+
+/**
+ * Paused is the state when we're enabled and and currently in a didPause
+ * callback.
+ */
+class InspectorState::Paused : public InspectorState {
+ public:
+  static std::unique_ptr<InspectorState> make(Inspector &inspector) {
+    return std::make_unique<Paused>(inspector);
+  }
+
+  Paused(Inspector &inspector) : InspectorState(inspector) {}
+  ~Paused() {}
+
+  void onEnter(InspectorState *prevState) override;
+
+  void detach(std::shared_ptr<folly::Promise<folly::Unit>> promise) override;
+
+  std::pair<NextStatePtr, CommandPtr> didPause(MonitorLock &lock) override;
+  bool pushPendingFunc(folly::Func func) override;
+  void pushPendingEval(
+      uint32_t frameIndex,
+      const std::string &src,
+      std::shared_ptr<folly::Promise<facebook::hermes::debugger::EvalResult>>
+          promise,
+      folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+          resultTransformer) override;
+  void setPendingCommand(
+      debugger::Command command,
+      std::shared_ptr<folly::Promise<folly::Unit>> promise) override;
+
+  bool isPaused() const override {
+    return true;
+  }
+
+  const char *description() const override {
+    return "Paused";
+  }
+
+ private:
+  std::condition_variable hasPendingWork_;
+  std::vector<folly::Func> pendingFuncs_;
+  std::queue<PendingEval> pendingEvals_;
+  std::shared_ptr<folly::Promise<facebook::hermes::debugger::EvalResult>>
+      pendingEvalPromise_;
+  folly::Function<void(const facebook::hermes::debugger::EvalResult &)>
+      pendingEvalResultTransformer_;
+  std::unique_ptr<PendingCommand> pendingCommand_;
+  std::shared_ptr<folly::Promise<folly::Unit>> pendingDetach_;
+};
+
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/README.md

@@ -0,0 +1,113 @@
+hermes-inspector provides a bridge between the low-level debugging API exposed
+by Hermes and higher-level debugging protocols such as the Chrome DevTools
+protocol.
+
+# Targets
+
+ - chrome: classes that implement the Chrome DevTools Protocol adapter. Sits on
+   top of classes provided by the inspector target.
+ - detail: utility classes and functions
+ - inspector: protocol-independent classes that sit on top of the low-level
+   Hermes debugging API.
+
+# Testing
+
+Tests are implemented using gtest. Debug logging is enabled for tests, and you
+can get debug logs to show even when tests are passing by running the test
+executable directly:
+
+```
+$ buck build fbsource//xplat/hermes-inspector:chrome-tests
+$ buck-out/gen/hermes-inspector/chrome-tests
+[...]
+```
+
+You can use standard gtest filters to only execute a particular set of tests:
+
+```
+$ buck-out/gen/hermes-inspector/chrome-tests \
+    --gtest_filter='ConnectionTests.testSetBreakpoint'
+```
+
+You can debug the tests using lldb or gdb:
+
+```
+$ lldb buck-out/gen/hermes-inspector/chrome-tests
+$ gdb buck-out/gen/hermes-inspector/chrome-tests
+```
+
+# Formatting
+
+Make sure the code is formatted using the hermes clang-format rules before
+committing:
+
+```
+$ xplat/hermes-inspector/tools/format
+```
+
+We follow the clang format rules used by the rest of the Hermes project.
+
+# Adding Support For New Message Types
+
+To add support for a new Chrome DevTools protocol message, add the message you
+want to add to tools/message_types.txt, and re-run the message types generator:
+
+```
+$ xplat/hermes-inspector/tools/run_msggen
+```
+
+This will generate C++ structs for the new message type in
+`chrome/MessageTypes.{h,cpp}`.
+
+You'll then need to:
+
+1. Implement a message handler for the new message type in `chrome::Connection`.
+2. Implement a public API for the new message type in `Inspector`. This will
+   most likely return a `folly::Future` that the message handler in (1) can use
+   for chaining.
+3. Implement a private API for the new message type in `Inspector` that performs
+   the logic in Inspector's executor. (Inspector.cpp contains a comment
+   explaining why the executor is necessary.)
+4. Optionally, implement a method for the new message type in `InspectorState`.
+   In most cases this is probably not necessary--one of the existing methods in
+   `InspectorState` will work.
+
+For a diff that illustrates these steps, take a look at D6601459.
+
+# Testing Integration With Nuclide and Apps
+
+For now, the quickest way to use hermes-inspector in an app is with Eats. First,
+make sure the packager is running:
+
+```
+$ js1 run
+```
+
+Then, on Android, build the fbeats target:
+
+```
+$ buck install --run fbeats
+```
+
+On iOS, build the `//Apps/Internal/Eats:Eats` target:
+
+```
+$ buck install --run //Apps/Internal/Eats:Eats
+```
+
+You can also build `Eats` in Xcode using `arc focus` if you prefer an
+IDE:
+
+```
+$ arc focus --force-build \
+    -b //Apps/Internal/Eats:Eats \
+    cxxreact fbsource//xplat/hermes/API:HermesAPI fbsource//xplat/hermes/lib/VM:VM jsi \
+    jsinspector hermes-inspector FBReactKit FBReactModule FBCatalystWrapper \
+    fbsource//xplat/js:React fbsource//xplat/js/react-native-github:ReactInternal
+```
+
+For all the above commands, if you want to build the inspector `-O0` for better
+debug info, add the argument `--config hermes.build_mode=dbg`.
+
+You should then be able to launch the app and see it listed in the list of
+Mobile JS contexts in the Nuclide debugger.

ReactCommon/hermes/inspector/RuntimeAdapter.cpp

@@ -0,0 +1,25 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include "RuntimeAdapter.h"
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+
+RuntimeAdapter::~RuntimeAdapter() = default;
+
+void RuntimeAdapter::tickleJs() {}
+
+SharedRuntimeAdapter::SharedRuntimeAdapter(
+    std::shared_ptr<HermesRuntime> runtime)
+    : runtime_(std::move(runtime)) {}
+
+SharedRuntimeAdapter::~SharedRuntimeAdapter() = default;
+
+HermesRuntime &SharedRuntimeAdapter::getRuntime() {
+  return *runtime_;
+}
+
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/RuntimeAdapter.h

@@ -0,0 +1,59 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <memory>
+
+#include <hermes/hermes.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+
+/**
+ * RuntimeAdapter encapsulates a HermesRuntime object. The underlying Hermes
+ * runtime object should stay alive for at least as long as the RuntimeAdapter
+ * is alive.
+ */
+class RuntimeAdapter {
+ public:
+  virtual ~RuntimeAdapter() = 0;
+
+  /// getRuntime should return the Hermes runtime encapsulated by this adapter.
+  virtual HermesRuntime &getRuntime() = 0;
+
+  /// tickleJs is a method that subclasses can choose to override to make the
+  /// inspector more responsive. If overridden, it should call the "__tickleJs"
+  /// function. The call should occur with appropriate locking (e.g. via a
+  /// thread-safe runtime instance, or by enqueuing the call on to a dedicated
+  /// JS thread).
+  ///
+  /// This makes the inspector more responsive because it gives the inspector
+  /// the ability to force the process to enter the Hermes interpreter loop
+  /// soon. This is important because the inspector can only do a number of
+  /// important operations (like manipulating breakpoints) within the context of
+  /// a Hermes interperter loop.
+  ///
+  /// The default implementation does nothing.
+  virtual void tickleJs();
+};
+
+/**
+ * SharedRuntimeAdapter is a simple implementation of RuntimeAdapter that
+ * uses shared_ptr to hold on to the runtime. It's generally only used in tests,
+ * since it does not implement tickleJs.
+ */
+class SharedRuntimeAdapter : public RuntimeAdapter {
+ public:
+  SharedRuntimeAdapter(std::shared_ptr<HermesRuntime> runtime);
+  virtual ~SharedRuntimeAdapter();
+
+  HermesRuntime &getRuntime() override;
+
+ private:
+  std::shared_ptr<HermesRuntime> runtime_;
+};
+
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/AutoAttachUtils.cpp

@@ -0,0 +1,127 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include "AutoAttachUtils.h"
+
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include <folly/String.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+
+// The following code is copied from
+// https://phabricator.intern.facebook.com/diffusion/FBS/browse/master/xplat/js/react-native-github/ReactCommon/cxxreact/JSCExecutor.cpp;431c4d01b7072d9a1a52f8bd6c6ba2ff3e47e25d$250
+bool isNetworkInspected(
+    const std::string &owner,
+    const std::string &app,
+    const std::string &device) {
+  auto connect_socket = [](int socket_desc, std::string address, int port) {
+    if (socket_desc < 0) {
+      close(socket_desc);
+      return false;
+    }
+
+    struct timeval tv;
+    tv.tv_sec = 1;
+    tv.tv_usec = 0;
+    auto sock_opt_rcv_resp = setsockopt(
+        socket_desc,
+        SOL_SOCKET,
+        SO_RCVTIMEO,
+        (const char *)&tv,
+        sizeof(struct timeval));
+    if (sock_opt_rcv_resp < 0) {
+      close(socket_desc);
+      return false;
+    }
+
+    auto sock_opt_snd_resp = setsockopt(
+        socket_desc,
+        SOL_SOCKET,
+        SO_SNDTIMEO,
+        (const char *)&tv,
+        sizeof(struct timeval));
+    if (sock_opt_snd_resp < 0) {
+      close(socket_desc);
+      return false;
+    }
+
+    struct sockaddr_in server;
+    server.sin_addr.s_addr = inet_addr(address.c_str());
+    server.sin_family = AF_INET;
+    server.sin_port = htons(port);
+    auto connect_resp =
+        ::connect(socket_desc, (struct sockaddr *)&server, sizeof(server));
+    if (connect_resp < 0) {
+      ::close(socket_desc);
+      return false;
+    }
+
+    return true;
+  };
+
+  int socket_desc = socket(AF_INET, SOCK_STREAM, 0);
+
+  if (!connect_socket(socket_desc, "127.0.0.1", 8082)) {
+#if defined(__ANDROID__)
+    socket_desc = socket(AF_INET, SOCK_STREAM, 0);
+    if (!connect_socket(socket_desc, "10.0.2.2", 8082) /* emulator */) {
+      socket_desc = socket(AF_INET, SOCK_STREAM, 0);
+      if (!connect_socket(socket_desc, "10.0.3.2", 8082) /* genymotion */) {
+        return false;
+      }
+    }
+#else //! defined(__ANDROID__)
+    return false;
+#endif // defined(__ANDROID__)
+  }
+
+  std::string escapedOwner =
+      folly::uriEscape<std::string>(owner, folly::UriEscapeMode::QUERY);
+  std::string escapedApp =
+      folly::uriEscape<std::string>(app, folly::UriEscapeMode::QUERY);
+  std::string escapedDevice =
+      folly::uriEscape<std::string>(device, folly::UriEscapeMode::QUERY);
+  std::string msg = folly::to<std::string>(
+      "GET /autoattach?title=",
+      escapedOwner,
+      "&app=",
+      escapedApp,
+      "&device=",
+      escapedDevice,
+      " HTTP/1.1\r\n\r\n");
+  auto send_resp = ::send(socket_desc, msg.c_str(), msg.length(), 0);
+  if (send_resp < 0) {
+    close(socket_desc);
+    return false;
+  }
+
+  char server_reply[200];
+  server_reply[199] = '\0';
+  auto recv_resp =
+      ::recv(socket_desc, server_reply, sizeof(server_reply) - 1, 0);
+  if (recv_resp < 0) {
+    close(socket_desc);
+    return false;
+  }
+
+  std::string response(server_reply);
+  if (response.size() < 25) {
+    close(socket_desc);
+    return false;
+  }
+  auto responseCandidate = response.substr(response.size() - 25);
+  auto found =
+      responseCandidate.find("{\"autoattach\":true}") != std::string::npos;
+  close(socket_desc);
+  return found;
+}
+
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/AutoAttachUtils.h

@@ -0,0 +1,19 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <string>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+
+bool isNetworkInspected(
+    const std::string &owner,
+    const std::string &app,
+    const std::string &device);
+}
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/Connection.cpp

@@ -0,0 +1,668 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include "Connection.h"
+
+#include <cstdlib>
+#include <mutex>
+
+#include <folly/Conv.h>
+#include <folly/Executor.h>
+#include <folly/Function.h>
+#include <glog/logging.h>
+#include <hermes/inspector/Inspector.h>
+#include <hermes/inspector/chrome/MessageConverters.h>
+#include <hermes/inspector/chrome/RemoteObjectsTable.h>
+#include <hermes/inspector/detail/SerialExecutor.h>
+#include <hermes/inspector/detail/Thread.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+
+using ::facebook::react::ILocalConnection;
+using ::facebook::react::IRemoteConnection;
+using ::folly::Unit;
+
+namespace debugger = ::facebook::hermes::debugger;
+namespace inspector = ::facebook::hermes::inspector;
+namespace m = ::facebook::hermes::inspector::chrome::message;
+
+/*
+ * Connection::Impl
+ */
+
+class Connection::Impl : public inspector::InspectorObserver,
+                         public message::RequestHandler {
+ public:
+  Impl(
+      std::unique_ptr<RuntimeAdapter> adapter,
+      const std::string &title,
+      bool waitForDebugger);
+  ~Impl();
+
+  HermesRuntime &getRuntime();
+  std::string getTitle() const;
+
+  bool connect(std::unique_ptr<IRemoteConnection> remoteConn);
+  bool disconnect();
+  void sendMessage(std::string str);
+
+  /* InspectorObserver overrides */
+  void onBreakpointResolved(
+      Inspector &inspector,
+      const debugger::BreakpointInfo &info) override;
+  void onContextCreated(Inspector &inspector) override;
+  void onPause(Inspector &inspector, const debugger::ProgramState &state)
+      override;
+  void onResume(Inspector &inspector) override;
+  void onScriptParsed(Inspector &inspector, const ScriptInfo &info) override;
+  void onMessageAdded(Inspector &inspector, const ConsoleMessageInfo &info)
+      override;
+
+  /* RequestHandler overrides */
+  void handle(const m::UnknownRequest &req) override;
+  void handle(const m::debugger::DisableRequest &req) override;
+  void handle(const m::debugger::EnableRequest &req) override;
+  void handle(const m::debugger::EvaluateOnCallFrameRequest &req) override;
+  void handle(const m::debugger::PauseRequest &req) override;
+  void handle(const m::debugger::RemoveBreakpointRequest &req) override;
+  void handle(const m::debugger::ResumeRequest &req) override;
+  void handle(const m::debugger::SetBreakpointByUrlRequest &req) override;
+  void handle(const m::debugger::SetPauseOnExceptionsRequest &req) override;
+  void handle(const m::debugger::StepIntoRequest &req) override;
+  void handle(const m::debugger::StepOutRequest &req) override;
+  void handle(const m::debugger::StepOverRequest &req) override;
+  void handle(const m::runtime::EvaluateRequest &req) override;
+  void handle(const m::runtime::GetPropertiesRequest &req) override;
+
+ private:
+  std::vector<m::runtime::PropertyDescriptor> makePropsFromScope(
+      std::pair<uint32_t, uint32_t> frameAndScopeIndex,
+      const std::string &objectGroup,
+      const debugger::ProgramState &state);
+  std::vector<m::runtime::PropertyDescriptor> makePropsFromValue(
+      const jsi::Value &value,
+      const std::string &objectGroup,
+      bool onlyOwnProperties);
+
+  void sendToClient(const std::string &str);
+  void sendResponseToClient(const m::Response &resp);
+  folly::Function<void(const std::exception &)> sendErrorToClient(int id);
+  void sendResponseToClientViaExecutor(int id);
+  void sendResponseToClientViaExecutor(folly::Future<Unit> future, int id);
+  void sendNotificationToClientViaExecutor(const m::Notification &note);
+
+  std::shared_ptr<RuntimeAdapter> runtimeAdapter_;
+  std::string title_;
+
+  // connected_ is protected by connectionMutex_.
+  std::mutex connectionMutex_;
+  bool connected_;
+
+  // parsedScripts_ list stores file names of all scripts that have been
+  // parsed so that we could find script's file name by regex.
+  // This is similar to Inspector's loadedScripts_ map but we want to
+  // store this info here because searching file name that matches
+  // given regex (on setBreakpointByUrl command) is more related to Chrome
+  // protocol than to Hermes inspector.
+  // Access is protected by parsedScriptsMutex_.
+  std::mutex parsedScriptsMutex_;
+  std::vector<std::string> parsedScripts_;
+
+  // The rest of these member variables are only accessed via executor_.
+  std::unique_ptr<folly::Executor> executor_;
+  std::unique_ptr<IRemoteConnection> remoteConn_;
+  std::shared_ptr<inspector::Inspector> inspector_;
+
+  // objTable_ is protected by the inspector lock. It should only be accessed
+  // when the VM is paused, e.g. in an InspectorObserver callback or in an
+  // executeIfEnabled callback.
+  RemoteObjectsTable objTable_;
+};
+
+Connection::Impl::Impl(
+    std::unique_ptr<RuntimeAdapter> adapter,
+    const std::string &title,
+    bool waitForDebugger)
+    : runtimeAdapter_(std::move(adapter)),
+      title_(title),
+      connected_(false),
+      executor_(std::make_unique<inspector::detail::SerialExecutor>(
+          "hermes-chrome-inspector-conn")),
+      remoteConn_(nullptr),
+      inspector_(std::make_shared<inspector::Inspector>(
+          runtimeAdapter_,
+          *this,
+          waitForDebugger)) {
+  inspector_->installLogHandler();
+}
+
+Connection::Impl::~Impl() = default;
+
+HermesRuntime &Connection::Impl::getRuntime() {
+  return runtimeAdapter_->getRuntime();
+}
+
+std::string Connection::Impl::getTitle() const {
+  return title_;
+}
+
+bool Connection::Impl::connect(std::unique_ptr<IRemoteConnection> remoteConn) {
+  assert(remoteConn);
+  std::lock_guard<std::mutex> lock(connectionMutex_);
+
+  if (connected_) {
+    return false;
+  }
+
+  connected_ = true;
+  executor_->add([this, remoteConn = std::move(remoteConn)]() mutable {
+    remoteConn_ = std::move(remoteConn);
+  });
+
+  return true;
+}
+
+bool Connection::Impl::disconnect() {
+  std::lock_guard<std::mutex> lock(connectionMutex_);
+
+  if (!connected_) {
+    return false;
+  }
+
+  connected_ = false;
+
+  inspector_->disable().via(executor_.get()).thenValue([this](auto &&) {
+    // HACK:  We purposely call RemoteConnection::onDisconnect on a *different*
+    // rather than on this thread (the executor thread). This is to prevent this
+    // scenario:
+    //
+    // 1. RemoteConnection::onDisconnect runs on the executor thread
+    // 2. onDisconnect through a long chain of calls causes the Connection
+    //    destructor to run
+    // 3. The Connection destructor causes the SerialExecutor destructor to run.
+    // 4. The SerialExecutor destructor waits for all outstanding work items to
+    //    finish via a call to join().
+    // 5. join() fails, since the executor thread is trying to join against
+    //    itself.
+    //
+    // To prevent this chain of events, we always call onDisconnect on a
+    // different thread.
+    //
+    // See P59135203 for an example stack trace.
+    //
+    // One more hack: we use release() and delete instead of unique_ptr because
+    // detail::Thread expects a std::function, and std::function cannot capture
+    // move-only types like unique_ptr.
+    auto conn = remoteConn_.release();
+    inspector::detail::Thread disconnectLaterThread{
+        "hermes-chrome-inspector-conn-disconnect", [conn] {
+          conn->onDisconnect();
+          delete conn;
+        }};
+    disconnectLaterThread.detach();
+  });
+
+  return true;
+}
+
+void Connection::Impl::sendMessage(std::string str) {
+  executor_->add([this, str = std::move(str)]() mutable {
+    folly::Try<std::unique_ptr<m::Request>> maybeReq =
+        m::Request::fromJson(str);
+
+    if (maybeReq.hasException()) {
+      LOG(ERROR) << "Invalid request `" << str
+                 << "`: " << maybeReq.exception().what();
+      return;
+    }
+
+    auto &req = maybeReq.value();
+    if (req) {
+      req->accept(*this);
+    }
+  });
+}
+
+/*
+ * InspectorObserver overrides
+ */
+
+void Connection::Impl::onBreakpointResolved(
+    Inspector &inspector,
+    const debugger::BreakpointInfo &info) {
+  m::debugger::BreakpointResolvedNotification note;
+  note.breakpointId = folly::to<std::string>(info.id);
+  note.location = m::debugger::makeLocation(info.resolvedLocation);
+  sendNotificationToClientViaExecutor(note);
+}
+
+void Connection::Impl::onContextCreated(Inspector &inspector) {
+  // Right now, Hermes only has the notion of one JS context per VM instance,
+  // so we just always name the single JS context with id=1 and name=hermes.
+  m::runtime::ExecutionContextCreatedNotification note;
+  note.context.id = 1;
+  note.context.name = "hermes";
+
+  // isDefault and isPageContext are custom properties that the legacy RN to
+  // JSC adapter set for some unknown reason.
+  note.context.isDefault = true;
+  note.context.isPageContext = true;
+
+  sendNotificationToClientViaExecutor(note);
+}
+
+void Connection::Impl::onPause(
+    Inspector &inspector,
+    const debugger::ProgramState &state) {
+  m::debugger::PausedNotification note;
+  note.callFrames = m::debugger::makeCallFrames(state, objTable_, getRuntime());
+
+  switch (state.getPauseReason()) {
+    case debugger::PauseReason::Breakpoint:
+      // use other, chrome protocol has no reason specifically for breakpoints
+      note.reason = "other";
+
+// TODO: hermes hasn't implemented ProgramState::getBreakpoint yet
+#if HERMES_SUPPORTS_STATE_GET_BREAKPOINT
+      note.hitBreakpoints = std::vector<m::debugger::BreakpointId>();
+      note.hitBreakpoints->emplace_back(
+          folly::to<std::string>(state.getBreakpoint()));
+#endif
+
+      break;
+    case debugger::PauseReason::Exception:
+      note.reason = "exception";
+      break;
+    default:
+      note.reason = "other";
+      break;
+  }
+
+  sendNotificationToClientViaExecutor(note);
+}
+
+void Connection::Impl::onResume(Inspector &inspector) {
+  objTable_.releaseObjectGroup(BacktraceObjectGroup);
+
+  m::debugger::ResumedNotification note;
+  sendNotificationToClientViaExecutor(note);
+}
+
+void Connection::Impl::onScriptParsed(
+    Inspector &inspector,
+    const ScriptInfo &info) {
+  m::debugger::ScriptParsedNotification note;
+  note.scriptId = folly::to<std::string>(info.fileId);
+  note.url = info.fileName;
+
+  if (!info.sourceMappingUrl.empty()) {
+    note.sourceMapURL = info.sourceMappingUrl;
+  }
+
+  {
+    std::lock_guard<std::mutex> lock(parsedScriptsMutex_);
+    parsedScripts_.push_back(info.fileName);
+  }
+
+  sendNotificationToClientViaExecutor(note);
+}
+
+void Connection::Impl::onMessageAdded(
+    facebook::hermes::inspector::Inspector &inspector,
+    const ConsoleMessageInfo &info) {
+  m::runtime::ConsoleAPICalledNotification apiCalledNote;
+  apiCalledNote.type = info.level;
+
+  size_t argsSize = info.args.size(getRuntime());
+  for (size_t index = 0; index < argsSize; ++index) {
+    apiCalledNote.args.push_back(m::runtime::makeRemoteObject(
+        getRuntime(),
+        info.args.getValueAtIndex(getRuntime(), index),
+        objTable_,
+        "ConsoleObjectGroup"));
+  }
+
+  sendNotificationToClientViaExecutor(apiCalledNote);
+}
+
+/*
+ * RequestHandler overrides
+ */
+
+void Connection::Impl::handle(const m::UnknownRequest &req) {
+  LOG(INFO) << "responding ok to unknown request: " << req.toDynamic();
+  sendResponseToClientViaExecutor(req.id);
+}
+
+void Connection::Impl::handle(const m::debugger::DisableRequest &req) {
+  sendResponseToClientViaExecutor(inspector_->disable(), req.id);
+}
+
+void Connection::Impl::handle(const m::debugger::EnableRequest &req) {
+  sendResponseToClientViaExecutor(inspector_->enable(), req.id);
+}
+
+void Connection::Impl::handle(
+    const m::debugger::EvaluateOnCallFrameRequest &req) {
+  auto remoteObjPtr = std::make_shared<m::runtime::RemoteObject>();
+
+  inspector_
+      ->evaluate(
+          atoi(req.callFrameId.c_str()),
+          req.expression,
+          [this, remoteObjPtr, objectGroup = req.objectGroup](
+              const facebook::hermes::debugger::EvalResult
+                  &evalResult) mutable {
+            *remoteObjPtr = m::runtime::makeRemoteObject(
+                getRuntime(),
+                evalResult.value,
+                objTable_,
+                objectGroup.value_or(""));
+          })
+      .via(executor_.get())
+      .thenValue(
+          [this, id = req.id, remoteObjPtr](debugger::EvalResult result) {
+            m::debugger::EvaluateOnCallFrameResponse resp;
+            resp.id = id;
+
+            if (result.isException) {
+              resp.exceptionDetails =
+                  m::runtime::makeExceptionDetails(result.exceptionDetails);
+            } else {
+              resp.result = *remoteObjPtr;
+            }
+
+            sendResponseToClient(resp);
+          })
+      .thenError<std::exception>(sendErrorToClient(req.id));
+}
+
+void Connection::Impl::handle(const m::runtime::EvaluateRequest &req) {
+  auto remoteObjPtr = std::make_shared<m::runtime::RemoteObject>();
+
+  inspector_
+      ->evaluate(
+          0, // Top of the stackframe
+          req.expression,
+          [this, remoteObjPtr, objectGroup = req.objectGroup](
+              const facebook::hermes::debugger::EvalResult
+                  &evalResult) mutable {
+            *remoteObjPtr = m::runtime::makeRemoteObject(
+                getRuntime(),
+                evalResult.value,
+                objTable_,
+                objectGroup.value_or("ConsoleObjectGroup"));
+          })
+      .via(executor_.get())
+      .thenValue(
+          [this, id = req.id, remoteObjPtr](debugger::EvalResult result) {
+            m::debugger::EvaluateOnCallFrameResponse resp;
+            resp.id = id;
+
+            if (result.isException) {
+              resp.exceptionDetails =
+                  m::runtime::makeExceptionDetails(result.exceptionDetails);
+            } else {
+              resp.result = *remoteObjPtr;
+            }
+
+            sendResponseToClient(resp);
+          })
+      .thenError<std::exception>(sendErrorToClient(req.id));
+}
+
+void Connection::Impl::handle(const m::debugger::PauseRequest &req) {
+  sendResponseToClientViaExecutor(inspector_->pause(), req.id);
+}
+
+void Connection::Impl::handle(const m::debugger::RemoveBreakpointRequest &req) {
+  auto breakpointId = folly::to<debugger::BreakpointID>(req.breakpointId);
+  sendResponseToClientViaExecutor(
+      inspector_->removeBreakpoint(breakpointId), req.id);
+}
+
+void Connection::Impl::handle(const m::debugger::ResumeRequest &req) {
+  sendResponseToClientViaExecutor(inspector_->resume(), req.id);
+}
+
+void Connection::Impl::handle(
+    const m::debugger::SetBreakpointByUrlRequest &req) {
+  debugger::SourceLocation loc;
+
+  {
+    std::lock_guard<std::mutex> lock(parsedScriptsMutex_);
+    setHermesLocation(loc, req, parsedScripts_);
+  }
+
+  inspector_->setBreakpoint(loc, req.condition)
+      .via(executor_.get())
+      .thenValue([this, id = req.id](debugger::BreakpointInfo info) {
+        m::debugger::SetBreakpointByUrlResponse resp;
+        resp.id = id;
+        resp.breakpointId = folly::to<std::string>(info.id);
+
+        if (info.resolved) {
+          resp.locations.emplace_back(
+              m::debugger::makeLocation(info.resolvedLocation));
+        }
+
+        sendResponseToClient(resp);
+      })
+      .thenError<std::exception>(sendErrorToClient(req.id));
+}
+
+void Connection::Impl::handle(
+    const m::debugger::SetPauseOnExceptionsRequest &req) {
+  debugger::PauseOnThrowMode mode = debugger::PauseOnThrowMode::None;
+
+  if (req.state == "none") {
+    mode = debugger::PauseOnThrowMode::None;
+  } else if (req.state == "all") {
+    mode = debugger::PauseOnThrowMode::All;
+  } else if (req.state == "uncaught") {
+    mode = debugger::PauseOnThrowMode::Uncaught;
+  } else {
+    sendErrorToClient(req.id);
+  }
+
+  sendResponseToClientViaExecutor(
+      inspector_->setPauseOnExceptions(mode), req.id);
+}
+
+void Connection::Impl::handle(const m::debugger::StepIntoRequest &req) {
+  sendResponseToClientViaExecutor(inspector_->stepIn(), req.id);
+}
+
+void Connection::Impl::handle(const m::debugger::StepOutRequest &req) {
+  sendResponseToClientViaExecutor(inspector_->stepOut(), req.id);
+}
+
+void Connection::Impl::handle(const m::debugger::StepOverRequest &req) {
+  sendResponseToClientViaExecutor(inspector_->stepOver(), req.id);
+}
+
+std::vector<m::runtime::PropertyDescriptor>
+Connection::Impl::makePropsFromScope(
+    std::pair<uint32_t, uint32_t> frameAndScopeIndex,
+    const std::string &objectGroup,
+    const debugger::ProgramState &state) {
+  std::vector<m::runtime::PropertyDescriptor> result;
+
+  uint32_t frameIndex = frameAndScopeIndex.first;
+  uint32_t scopeIndex = frameAndScopeIndex.second;
+  debugger::LexicalInfo lexicalInfo = state.getLexicalInfo(frameIndex);
+  uint32_t varCount = lexicalInfo.getVariablesCountInScope(scopeIndex);
+
+  for (uint32_t varIndex = 0; varIndex < varCount; varIndex++) {
+    debugger::VariableInfo varInfo =
+        state.getVariableInfo(frameIndex, scopeIndex, varIndex);
+
+    m::runtime::PropertyDescriptor desc;
+    desc.name = varInfo.name;
+    desc.value = m::runtime::makeRemoteObject(
+        getRuntime(), varInfo.value, objTable_, objectGroup);
+
+    result.emplace_back(std::move(desc));
+  }
+
+  return result;
+}
+
+std::vector<m::runtime::PropertyDescriptor>
+Connection::Impl::makePropsFromValue(
+    const jsi::Value &value,
+    const std::string &objectGroup,
+    bool onlyOwnProperties) {
+  std::vector<m::runtime::PropertyDescriptor> result;
+
+  if (value.isObject()) {
+    HermesRuntime &runtime = getRuntime();
+    jsi::Object obj = value.getObject(runtime);
+
+    // TODO(hypuk): obj.getPropertyNames only returns enumerable properties.
+    jsi::Array propNames = onlyOwnProperties
+        ? runtime.global()
+              .getPropertyAsObject(runtime, "Object")
+              .getPropertyAsFunction(runtime, "getOwnPropertyNames")
+              .call(runtime, obj)
+              .getObject(runtime)
+              .getArray(runtime)
+        : obj.getPropertyNames(runtime);
+
+    size_t propCount = propNames.length(runtime);
+    for (size_t i = 0; i < propCount; i++) {
+      jsi::String propName =
+          propNames.getValueAtIndex(runtime, i).getString(runtime);
+
+      m::runtime::PropertyDescriptor desc;
+      desc.name = propName.utf8(runtime);
+
+      jsi::Value propValue = obj.getProperty(runtime, propName);
+      desc.value = m::runtime::makeRemoteObject(
+          runtime, propValue, objTable_, objectGroup);
+
+      result.emplace_back(std::move(desc));
+    }
+
+    if (onlyOwnProperties) {
+      jsi::Value proto = runtime.global()
+                             .getPropertyAsObject(runtime, "Object")
+                             .getPropertyAsFunction(runtime, "getPrototypeOf")
+                             .call(runtime, obj);
+      if (!proto.isNull()) {
+        m::runtime::PropertyDescriptor desc;
+        desc.name = "__proto__";
+        desc.value = m::runtime::makeRemoteObject(
+            runtime, proto, objTable_, objectGroup);
+        result.emplace_back(std::move(desc));
+      }
+    }
+  }
+
+  return result;
+}
+
+void Connection::Impl::handle(const m::runtime::GetPropertiesRequest &req) {
+  auto resp = std::make_shared<m::runtime::GetPropertiesResponse>();
+  resp->id = req.id;
+
+  inspector_
+      ->executeIfEnabled(
+          "Runtime.getProperties",
+          [this, req, resp](const debugger::ProgramState &state) {
+            std::string objGroup = objTable_.getObjectGroup(req.objectId);
+            auto scopePtr = objTable_.getScope(req.objectId);
+            auto valuePtr = objTable_.getValue(req.objectId);
+
+            if (scopePtr != nullptr) {
+              resp->result = makePropsFromScope(*scopePtr, objGroup, state);
+            } else if (valuePtr != nullptr) {
+              resp->result = makePropsFromValue(
+                  *valuePtr, objGroup, req.ownProperties.value_or(true));
+            }
+          })
+      .via(executor_.get())
+      .thenValue([this, resp](auto &&) { sendResponseToClient(*resp); })
+      .thenError<std::exception>(sendErrorToClient(req.id));
+}
+
+/*
+ * Send-to-client methods
+ */
+
+void Connection::Impl::sendToClient(const std::string &str) {
+  if (remoteConn_) {
+    remoteConn_->onMessage(str);
+  }
+}
+
+void Connection::Impl::sendResponseToClient(const m::Response &resp) {
+  sendToClient(resp.toJson());
+}
+
+folly::Function<void(const std::exception &)>
+Connection::Impl::sendErrorToClient(int id) {
+  return [this, id](const std::exception &e) {
+    sendResponseToClient(
+        m::makeErrorResponse(id, m::ErrorCode::ServerError, e.what()));
+  };
+}
+
+void Connection::Impl::sendResponseToClientViaExecutor(int id) {
+  sendResponseToClientViaExecutor(folly::makeFuture(), id);
+}
+
+void Connection::Impl::sendResponseToClientViaExecutor(
+    folly::Future<Unit> future,
+    int id) {
+  future.via(executor_.get())
+      .thenValue([this, id](const Unit &unit) {
+        sendResponseToClient(m::makeOkResponse(id));
+      })
+      .thenError<std::exception>(sendErrorToClient(id));
+}
+
+void Connection::Impl::sendNotificationToClientViaExecutor(
+    const m::Notification &note) {
+  executor_->add(
+      [this, noteJson = note.toJson()]() { sendToClient(noteJson); });
+}
+
+/*
+ * Connection
+ */
+Connection::Connection(
+    std::unique_ptr<RuntimeAdapter> adapter,
+    const std::string &title,
+    bool waitForDebugger)
+    : impl_(
+          std::make_unique<Impl>(std::move(adapter), title, waitForDebugger)) {}
+
+Connection::~Connection() = default;
+
+HermesRuntime &Connection::getRuntime() {
+  return impl_->getRuntime();
+}
+
+std::string Connection::getTitle() const {
+  return impl_->getTitle();
+}
+
+bool Connection::connect(std::unique_ptr<IRemoteConnection> remoteConn) {
+  return impl_->connect(std::move(remoteConn));
+}
+
+bool Connection::disconnect() {
+  return impl_->disconnect();
+}
+
+void Connection::sendMessage(std::string str) {
+  impl_->sendMessage(std::move(str));
+}
+
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/Connection.h

@@ -0,0 +1,58 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <functional>
+#include <memory>
+#include <string>
+
+#include <hermes/hermes.h>
+#include <hermes/inspector/RuntimeAdapter.h>
+#include <hermes/inspector/chrome/MessageTypes.h>
+#include <jsinspector/InspectorInterfaces.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+
+/// Connection is a duplex connection between the client and the debugger.
+class Connection {
+ public:
+  /// Connection constructor enables the debugger on the provided runtime. This
+  /// should generally called before you start running any JS in the runtime.
+  Connection(
+      std::unique_ptr<RuntimeAdapter> adapter,
+      const std::string &title,
+      bool waitForDebugger = false);
+  ~Connection();
+
+  /// getRuntime returns the underlying runtime being debugged.
+  HermesRuntime &getRuntime();
+
+  /// getTitle returns the name of the friendly name of the runtime that's shown
+  /// to users in Nuclide.
+  std::string getTitle() const;
+
+  /// connect attaches this connection to the runtime's debugger. Requests to
+  /// the debugger sent via send(). Replies and notifications from the debugger
+  /// are sent back to the client via IRemoteConnection::onMessage.
+  bool connect(
+      std::unique_ptr<::facebook::react::IRemoteConnection> remoteConn);
+
+  /// disconnect disconnects this connection from the runtime's debugger
+  bool disconnect();
+
+  /// sendMessage delivers a JSON-encoded Chrome DevTools Protocol request to
+  /// the debugger.
+  void sendMessage(std::string str);
+
+ private:
+  class Impl;
+  std::unique_ptr<Impl> impl_;
+};
+
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/ConnectionDemux.cpp

@@ -0,0 +1,137 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include "ConnectionDemux.h"
+#include "AutoAttachUtils.h"
+#include "Connection.h"
+
+#include <jsinspector/InspectorInterfaces.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+
+using ::facebook::react::IInspector;
+using ::facebook::react::ILocalConnection;
+using ::facebook::react::IRemoteConnection;
+
+namespace {
+
+class LocalConnection : public ILocalConnection {
+ public:
+  LocalConnection(
+      std::shared_ptr<Connection> conn,
+      std::shared_ptr<std::unordered_set<std::string>> inspectedContexts);
+  ~LocalConnection();
+
+  void sendMessage(std::string message) override;
+  void disconnect() override;
+
+ private:
+  std::shared_ptr<Connection> conn_;
+  std::shared_ptr<std::unordered_set<std::string>> inspectedContexts_;
+};
+
+LocalConnection::LocalConnection(
+    std::shared_ptr<Connection> conn,
+    std::shared_ptr<std::unordered_set<std::string>> inspectedContexts)
+    : conn_(conn), inspectedContexts_(inspectedContexts) {
+  inspectedContexts_->insert(conn->getTitle());
+}
+
+LocalConnection::~LocalConnection() = default;
+
+void LocalConnection::sendMessage(std::string str) {
+  conn_->sendMessage(std::move(str));
+}
+
+void LocalConnection::disconnect() {
+  inspectedContexts_->erase(conn_->getTitle());
+  conn_->disconnect();
+}
+
+} // namespace
+
+ConnectionDemux::ConnectionDemux(facebook::react::IInspector &inspector)
+    : globalInspector_(inspector),
+      inspectedContexts_(std::make_shared<std::unordered_set<std::string>>()) {}
+
+ConnectionDemux::~ConnectionDemux() = default;
+
+int ConnectionDemux::enableDebugging(
+    std::unique_ptr<RuntimeAdapter> adapter,
+    const std::string &title) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  // TODO(#22976087): workaround for ComponentScript contexts never being
+  // destroyed.
+  //
+  // After a reload, the old ComponentScript VM instance stays alive. When we
+  // register the new CS VM instance, check for any previous CS VM (via strcmp
+  // of title) and remove them.
+  std::vector<int> pagesToDelete;
+  for (auto it = conns_.begin(); it != conns_.end(); ++it) {
+    if (it->second->getTitle() == title) {
+      pagesToDelete.push_back(it->first);
+    }
+  }
+
+  for (auto pageId : pagesToDelete) {
+    removePage(pageId);
+  }
+
+  // TODO(hypuk): Provide real app and device names.
+  auto waitForDebugger =
+      (inspectedContexts_->find(title) != inspectedContexts_->end()) ||
+      isNetworkInspected(title, "app_name", "device_name");
+
+  return addPage(
+      std::make_shared<Connection>(std::move(adapter), title, waitForDebugger));
+}
+
+void ConnectionDemux::disableDebugging(HermesRuntime &runtime) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  for (auto &it : conns_) {
+    int pageId = it.first;
+    auto &conn = it.second;
+
+    if (&(conn->getRuntime()) == &runtime) {
+      removePage(pageId);
+
+      // must break here. removePage mutates conns_, so range-for iterator is
+      // now invalid.
+      break;
+    }
+  }
+}
+
+int ConnectionDemux::addPage(std::shared_ptr<Connection> conn) {
+  auto connectFunc = [conn, this](std::unique_ptr<IRemoteConnection> remoteConn)
+      -> std::unique_ptr<ILocalConnection> {
+    if (!conn->connect(std::move(remoteConn))) {
+      return nullptr;
+    }
+
+    return std::make_unique<LocalConnection>(conn, inspectedContexts_);
+  };
+
+  int pageId = globalInspector_.addPage(
+      conn->getTitle(), "Hermes", std::move(connectFunc));
+  conns_[pageId] = std::move(conn);
+
+  return pageId;
+}
+
+void ConnectionDemux::removePage(int pageId) {
+  globalInspector_.removePage(pageId);
+
+  auto conn = conns_.at(pageId);
+  conn->disconnect();
+  conns_.erase(pageId);
+}
+
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/ConnectionDemux.h

@@ -0,0 +1,52 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <memory>
+#include <mutex>
+#include <string>
+#include <unordered_map>
+
+#include <hermes/hermes.h>
+#include <hermes/inspector/RuntimeAdapter.h>
+#include <hermes/inspector/chrome/Connection.h>
+#include <jsinspector/InspectorInterfaces.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+
+/*
+ * ConnectionDemux keeps track of all debuggable Hermes runtimes (called
+ * "pages" in the higher-level React Native API) in this process. See
+ * Registration.h for documentation of the public API.
+ */
+class ConnectionDemux {
+ public:
+  explicit ConnectionDemux(facebook::react::IInspector &inspector);
+  ~ConnectionDemux();
+
+  ConnectionDemux(const ConnectionDemux &) = delete;
+  ConnectionDemux &operator=(const ConnectionDemux &) = delete;
+
+  int enableDebugging(
+      std::unique_ptr<RuntimeAdapter> adapter,
+      const std::string &title);
+  void disableDebugging(HermesRuntime &runtime);
+
+ private:
+  int addPage(std::shared_ptr<Connection> conn);
+  void removePage(int pageId);
+
+  facebook::react::IInspector &globalInspector_;
+
+  std::mutex mutex_;
+  std::unordered_map<int, std::shared_ptr<Connection>> conns_;
+  std::shared_ptr<std::unordered_set<std::string>> inspectedContexts_;
+};
+
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/MessageConverters.cpp

@@ -0,0 +1,215 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include "MessageConverters.h"
+
+#include <cmath>
+#include <limits>
+
+#include <folly/Conv.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+
+namespace h = ::facebook::hermes;
+namespace m = ::facebook::hermes::inspector::chrome::message;
+
+m::ErrorResponse
+m::makeErrorResponse(int id, m::ErrorCode code, const std::string &message) {
+  m::ErrorResponse resp;
+  resp.id = id;
+  resp.code = static_cast<int>(code);
+  resp.message = message;
+  return resp;
+}
+
+m::OkResponse m::makeOkResponse(int id) {
+  m::OkResponse resp;
+  resp.id = id;
+  return resp;
+}
+
+/*
+ * debugger message conversion helpers
+ */
+
+m::debugger::Location m::debugger::makeLocation(
+    const h::debugger::SourceLocation &loc) {
+  m::debugger::Location result;
+
+  result.scriptId = folly::to<std::string>(loc.fileId);
+  m::setChromeLocation(result, loc);
+
+  return result;
+}
+
+m::debugger::CallFrame m::debugger::makeCallFrame(
+    uint32_t callFrameIndex,
+    const h::debugger::CallFrameInfo &callFrameInfo,
+    const h::debugger::LexicalInfo &lexicalInfo,
+    RemoteObjectsTable &objTable,
+    HermesRuntime &runtime,
+    const facebook::hermes::debugger::ProgramState &state) {
+  m::debugger::CallFrame result;
+
+  result.callFrameId = folly::to<std::string>(callFrameIndex);
+  result.functionName = callFrameInfo.functionName;
+  result.location = makeLocation(callFrameInfo.location);
+
+  uint32_t scopeCount = lexicalInfo.getScopesCount();
+  for (uint32_t scopeIndex = 0; scopeIndex < scopeCount; scopeIndex++) {
+    m::debugger::Scope scope;
+
+    if (scopeIndex == scopeCount - 1) {
+      scope.type = "global";
+      scope.name = "Global Scope";
+      scope.object.objectId =
+          objTable.addValue(runtime.global(), BacktraceObjectGroup);
+    } else {
+      scope.type = "local";
+      scope.name = "Scope " + folly::to<std::string>(scopeIndex);
+      scope.object.objectId = objTable.addScope(
+          std::make_pair(callFrameIndex, scopeIndex), BacktraceObjectGroup);
+    }
+
+    scope.object.type = "object";
+    scope.object.className = "Object";
+    result.scopeChain.emplace_back(std::move(scope));
+  }
+
+  result.thisObj.type = "object";
+  result.thisObj.objectId = objTable.addValue(
+      state.getVariableInfoForThis(callFrameIndex).value, BacktraceObjectGroup);
+
+  return result;
+}
+
+std::vector<m::debugger::CallFrame> m::debugger::makeCallFrames(
+    const h::debugger::ProgramState &state,
+    RemoteObjectsTable &objTable,
+    HermesRuntime &runtime) {
+  const h::debugger::StackTrace &stackTrace = state.getStackTrace();
+  uint32_t count = stackTrace.callFrameCount();
+
+  std::vector<m::debugger::CallFrame> result;
+  result.reserve(count);
+
+  for (uint32_t i = 0; i < count; i++) {
+    h::debugger::CallFrameInfo callFrameInfo = stackTrace.callFrameForIndex(i);
+    h::debugger::LexicalInfo lexicalInfo = state.getLexicalInfo(i);
+
+    result.emplace_back(
+        makeCallFrame(i, callFrameInfo, lexicalInfo, objTable, runtime, state));
+  }
+
+  return result;
+}
+
+/*
+ * runtime message conversion helpers
+ */
+
+m::runtime::CallFrame m::runtime::makeCallFrame(
+    const h::debugger::CallFrameInfo &info) {
+  m::runtime::CallFrame result;
+
+  result.functionName = info.functionName;
+  result.scriptId = folly::to<std::string>(info.location.fileId);
+  result.url = info.location.fileName;
+  m::setChromeLocation(result, info.location);
+
+  return result;
+}
+
+std::vector<m::runtime::CallFrame> m::runtime::makeCallFrames(
+    const facebook::hermes::debugger::StackTrace &stackTrace) {
+  std::vector<m::runtime::CallFrame> result;
+  result.reserve(stackTrace.callFrameCount());
+
+  for (size_t i = 0; i < stackTrace.callFrameCount(); i++) {
+    h::debugger::CallFrameInfo info = stackTrace.callFrameForIndex(i);
+    result.emplace_back(makeCallFrame(info));
+  }
+
+  return result;
+}
+
+m::runtime::ExceptionDetails m::runtime::makeExceptionDetails(
+    const h::debugger::ExceptionDetails &details) {
+  m::runtime::ExceptionDetails result;
+
+  result.text = details.text;
+  result.scriptId = folly::to<std::string>(details.location.fileId);
+  result.url = details.location.fileName;
+  result.stackTrace = m::runtime::StackTrace();
+  result.stackTrace->callFrames = makeCallFrames(details.getStackTrace());
+  m::setChromeLocation(result, details.location);
+
+  return result;
+}
+
+m::runtime::RemoteObject m::runtime::makeRemoteObject(
+    facebook::jsi::Runtime &runtime,
+    const facebook::jsi::Value &value,
+    RemoteObjectsTable &objTable,
+    const std::string &objectGroup) {
+  m::runtime::RemoteObject result;
+
+  if (value.isUndefined()) {
+    result.type = "undefined";
+  } else if (value.isNull()) {
+    result.type = "object";
+    result.subtype = "null";
+    result.value = "null";
+  } else if (value.isBool()) {
+    result.type = "boolean";
+    result.value = value.getBool();
+  } else if (value.isNumber()) {
+    double numberValue = value.getNumber();
+
+    result.type = "number";
+    if (std::isnan(numberValue)) {
+      result.description = result.unserializableValue = "NaN";
+    } else if (numberValue == -std::numeric_limits<double>::infinity()) {
+      result.description = result.unserializableValue = "-Infinity";
+    } else if (numberValue == std::numeric_limits<double>::infinity()) {
+      result.description = result.unserializableValue = "Infinity";
+    } else if (numberValue == 0.0 && std::signbit(numberValue)) {
+      result.description = result.unserializableValue = "-0";
+    } else {
+      result.value = numberValue;
+    }
+  } else if (value.isString()) {
+    result.type = "string";
+    result.value = value.getString(runtime).utf8(runtime);
+  } else if (value.isObject()) {
+    jsi::Object obj = value.getObject(runtime);
+
+    if (obj.isFunction(runtime)) {
+      result.type = "function";
+      result.value = "";
+    } else if (obj.isArray(runtime)) {
+      auto array = obj.getArray(runtime);
+      size_t arrayCount = array.length(runtime);
+
+      result.type = "object";
+      result.subtype = "array";
+      result.className = "Array";
+      result.description = "Array(" + folly::to<std::string>(arrayCount) + ")";
+    } else {
+      result.type = "object";
+      result.description = result.className = "Object";
+    }
+
+    result.objectId =
+        objTable.addValue(jsi::Value(std::move(obj)), objectGroup);
+  }
+
+  return result;
+}
+
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/MessageConverters.h

@@ -0,0 +1,121 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <regex>
+#include <string>
+#include <vector>
+
+#include <hermes/DebuggerAPI.h>
+#include <hermes/hermes.h>
+#include <hermes/inspector/chrome/MessageTypes.h>
+#include <hermes/inspector/chrome/RemoteObjectsTable.h>
+#include <jsi/jsi.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+namespace message {
+
+template <typename T>
+void setHermesLocation(
+    facebook::hermes::debugger::SourceLocation &hermesLoc,
+    const T &chromeLoc,
+    const std::vector<std::string> &parsedScripts) {
+  hermesLoc.line = chromeLoc.lineNumber + 1;
+
+  if (chromeLoc.columnNumber.hasValue()) {
+    if (chromeLoc.columnNumber.value() == 0) {
+      // TODO: When CDTP sends a column number of 0, we send Hermes a column
+      // number of 1. For some reason, this causes Hermes to not be
+      // able to resolve breakpoints.
+      hermesLoc.column = ::facebook::hermes::debugger::kInvalidLocation;
+    } else {
+      hermesLoc.column = chromeLoc.columnNumber.value() + 1;
+    }
+  }
+
+  if (chromeLoc.url.hasValue()) {
+    hermesLoc.fileName = chromeLoc.url.value();
+  } else if (chromeLoc.urlRegex.hasValue()) {
+    const std::regex regex(chromeLoc.urlRegex.value());
+    for (const auto &fileName : parsedScripts) {
+      if (std::regex_match(fileName, regex)) {
+        hermesLoc.fileName = fileName;
+        break;
+      }
+    }
+  }
+}
+
+template <typename T>
+void setChromeLocation(
+    T &chromeLoc,
+    const facebook::hermes::debugger::SourceLocation &hermesLoc) {
+  if (hermesLoc.line != facebook::hermes::debugger::kInvalidLocation) {
+    chromeLoc.lineNumber = hermesLoc.line - 1;
+  }
+
+  if (hermesLoc.column != facebook::hermes::debugger::kInvalidLocation) {
+    chromeLoc.columnNumber = hermesLoc.column - 1;
+  }
+}
+
+/// ErrorCode magic numbers match JSC's (see InspectorBackendDispatcher.cpp)
+enum class ErrorCode {
+  ParseError = -32700,
+  InvalidRequest = -32600,
+  MethodNotFound = -32601,
+  InvalidParams = -32602,
+  InternalError = -32603,
+  ServerError = -32000
+};
+
+ErrorResponse
+makeErrorResponse(int id, ErrorCode code, const std::string &message);
+
+OkResponse makeOkResponse(int id);
+
+namespace debugger {
+
+Location makeLocation(const facebook::hermes::debugger::SourceLocation &loc);
+
+CallFrame makeCallFrame(
+    uint32_t callFrameIndex,
+    const facebook::hermes::debugger::CallFrameInfo &callFrameInfo,
+    const facebook::hermes::debugger::LexicalInfo &lexicalInfo,
+    facebook::hermes::inspector::chrome::RemoteObjectsTable &objTable,
+    HermesRuntime &runtime,
+    const facebook::hermes::debugger::ProgramState &state);
+
+std::vector<CallFrame> makeCallFrames(
+    const facebook::hermes::debugger::ProgramState &state,
+    facebook::hermes::inspector::chrome::RemoteObjectsTable &objTable,
+    HermesRuntime &runtime);
+
+} // namespace debugger
+
+namespace runtime {
+
+CallFrame makeCallFrame(const facebook::hermes::debugger::CallFrameInfo &info);
+
+std::vector<CallFrame> makeCallFrames(
+    const facebook::hermes::debugger::StackTrace &stackTrace);
+
+ExceptionDetails makeExceptionDetails(
+    const facebook::hermes::debugger::ExceptionDetails &details);
+
+RemoteObject makeRemoteObject(
+    facebook::jsi::Runtime &runtime,
+    const facebook::jsi::Value &value,
+    facebook::hermes::inspector::chrome::RemoteObjectsTable &objTable,
+    const std::string &objectGroup);
+
+} // namespace runtime
+
+} // namespace message
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/MessageInterfaces.h

@@ -0,0 +1,69 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+
+#include <folly/Try.h>
+#include <folly/dynamic.h>
+#include <folly/json.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+namespace message {
+
+struct RequestHandler;
+
+/// Serializable is an interface for objects that can be serialized to and from
+/// JSON.
+struct Serializable {
+  virtual ~Serializable() = default;
+  virtual folly::dynamic toDynamic() const = 0;
+
+  std::string toJson() const {
+    return folly::toJson(toDynamic());
+  }
+};
+
+/// Requests are sent from the debugger to the target.
+struct Request : public Serializable {
+  static std::unique_ptr<Request> fromJsonThrowOnError(const std::string &str);
+  static folly::Try<std::unique_ptr<Request>> fromJson(const std::string &str);
+
+  Request() = default;
+  explicit Request(std::string method) : method(method) {}
+
+  // accept dispatches to the appropriate handler method in RequestHandler based
+  // on the type of the request.
+  virtual void accept(RequestHandler &handler) const = 0;
+
+  int id = 0;
+  std::string method;
+};
+
+/// Responses are sent from the target to the debugger in response to a Request.
+struct Response : public Serializable {
+  Response() = default;
+
+  int id = 0;
+};
+
+/// Notifications are sent from the target to the debugger. This is used to
+/// notify the debugger about events that occur in the target, e.g. stopping
+/// at a breakpoint.
+struct Notification : public Serializable {
+  Notification() = default;
+  explicit Notification(std::string method) : method(method) {}
+
+  std::string method;
+};
+
+} // namespace message
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/MessageTypes.cpp

@@ -0,0 +1,902 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+// @generated <<SignedSource::*O*zOeWoEQle#+L!plEphiEmie@IsG>>
+
+#include "MessageTypes.h"
+
+#include "MessageTypesInlines.h"
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+namespace message {
+
+using RequestBuilder = std::unique_ptr<Request> (*)(const dynamic &);
+
+namespace {
+
+template <typename T>
+std::unique_ptr<Request> makeUnique(const dynamic &obj) {
+  return std::make_unique<T>(obj);
+}
+
+} // namespace
+
+std::unique_ptr<Request> Request::fromJsonThrowOnError(const std::string &str) {
+  static std::unordered_map<std::string, RequestBuilder> builders = {
+      {"Debugger.disable", makeUnique<debugger::DisableRequest>},
+      {"Debugger.enable", makeUnique<debugger::EnableRequest>},
+      {"Debugger.evaluateOnCallFrame",
+       makeUnique<debugger::EvaluateOnCallFrameRequest>},
+      {"Debugger.pause", makeUnique<debugger::PauseRequest>},
+      {"Debugger.removeBreakpoint",
+       makeUnique<debugger::RemoveBreakpointRequest>},
+      {"Debugger.resume", makeUnique<debugger::ResumeRequest>},
+      {"Debugger.setBreakpointByUrl",
+       makeUnique<debugger::SetBreakpointByUrlRequest>},
+      {"Debugger.setPauseOnExceptions",
+       makeUnique<debugger::SetPauseOnExceptionsRequest>},
+      {"Debugger.stepInto", makeUnique<debugger::StepIntoRequest>},
+      {"Debugger.stepOut", makeUnique<debugger::StepOutRequest>},
+      {"Debugger.stepOver", makeUnique<debugger::StepOverRequest>},
+      {"Runtime.evaluate", makeUnique<runtime::EvaluateRequest>},
+      {"Runtime.getProperties", makeUnique<runtime::GetPropertiesRequest>},
+  };
+
+  dynamic obj = folly::parseJson(str);
+  std::string method = obj.at("method").asString();
+
+  auto it = builders.find(method);
+  if (it == builders.end()) {
+    return std::make_unique<UnknownRequest>(obj);
+  }
+
+  auto builder = it->second;
+  return builder(obj);
+}
+
+folly::Try<std::unique_ptr<Request>> Request::fromJson(const std::string &str) {
+  return folly::makeTryWith(
+      [&str] { return Request::fromJsonThrowOnError(str); });
+}
+
+/// Types
+debugger::Location::Location(const dynamic &obj) {
+  assign(scriptId, obj, "scriptId");
+  assign(lineNumber, obj, "lineNumber");
+  assign(columnNumber, obj, "columnNumber");
+}
+
+dynamic debugger::Location::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "scriptId", scriptId);
+  put(obj, "lineNumber", lineNumber);
+  put(obj, "columnNumber", columnNumber);
+  return obj;
+}
+
+runtime::RemoteObject::RemoteObject(const dynamic &obj) {
+  assign(type, obj, "type");
+  assign(subtype, obj, "subtype");
+  assign(className, obj, "className");
+  assign(value, obj, "value");
+  assign(unserializableValue, obj, "unserializableValue");
+  assign(description, obj, "description");
+  assign(objectId, obj, "objectId");
+}
+
+dynamic runtime::RemoteObject::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "type", type);
+  put(obj, "subtype", subtype);
+  put(obj, "className", className);
+  put(obj, "value", value);
+  put(obj, "unserializableValue", unserializableValue);
+  put(obj, "description", description);
+  put(obj, "objectId", objectId);
+  return obj;
+}
+
+runtime::CallFrame::CallFrame(const dynamic &obj) {
+  assign(functionName, obj, "functionName");
+  assign(scriptId, obj, "scriptId");
+  assign(url, obj, "url");
+  assign(lineNumber, obj, "lineNumber");
+  assign(columnNumber, obj, "columnNumber");
+}
+
+dynamic runtime::CallFrame::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "functionName", functionName);
+  put(obj, "scriptId", scriptId);
+  put(obj, "url", url);
+  put(obj, "lineNumber", lineNumber);
+  put(obj, "columnNumber", columnNumber);
+  return obj;
+}
+
+runtime::StackTrace::StackTrace(const dynamic &obj) {
+  assign(description, obj, "description");
+  assign(callFrames, obj, "callFrames");
+  assign(parent, obj, "parent");
+}
+
+dynamic runtime::StackTrace::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "description", description);
+  put(obj, "callFrames", callFrames);
+  put(obj, "parent", parent);
+  return obj;
+}
+
+runtime::ExceptionDetails::ExceptionDetails(const dynamic &obj) {
+  assign(exceptionId, obj, "exceptionId");
+  assign(text, obj, "text");
+  assign(lineNumber, obj, "lineNumber");
+  assign(columnNumber, obj, "columnNumber");
+  assign(scriptId, obj, "scriptId");
+  assign(url, obj, "url");
+  assign(stackTrace, obj, "stackTrace");
+  assign(exception, obj, "exception");
+  assign(executionContextId, obj, "executionContextId");
+}
+
+dynamic runtime::ExceptionDetails::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "exceptionId", exceptionId);
+  put(obj, "text", text);
+  put(obj, "lineNumber", lineNumber);
+  put(obj, "columnNumber", columnNumber);
+  put(obj, "scriptId", scriptId);
+  put(obj, "url", url);
+  put(obj, "stackTrace", stackTrace);
+  put(obj, "exception", exception);
+  put(obj, "executionContextId", executionContextId);
+  return obj;
+}
+
+debugger::Scope::Scope(const dynamic &obj) {
+  assign(type, obj, "type");
+  assign(object, obj, "object");
+  assign(name, obj, "name");
+  assign(startLocation, obj, "startLocation");
+  assign(endLocation, obj, "endLocation");
+}
+
+dynamic debugger::Scope::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "type", type);
+  put(obj, "object", object);
+  put(obj, "name", name);
+  put(obj, "startLocation", startLocation);
+  put(obj, "endLocation", endLocation);
+  return obj;
+}
+
+debugger::CallFrame::CallFrame(const dynamic &obj) {
+  assign(callFrameId, obj, "callFrameId");
+  assign(functionName, obj, "functionName");
+  assign(location, obj, "location");
+  assign(url, obj, "url");
+  assign(scopeChain, obj, "scopeChain");
+  assign(thisObj, obj, "this");
+  assign(returnValue, obj, "returnValue");
+}
+
+dynamic debugger::CallFrame::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "callFrameId", callFrameId);
+  put(obj, "functionName", functionName);
+  put(obj, "location", location);
+  put(obj, "url", url);
+  put(obj, "scopeChain", scopeChain);
+  put(obj, "this", thisObj);
+  put(obj, "returnValue", returnValue);
+  return obj;
+}
+
+runtime::ExecutionContextDescription::ExecutionContextDescription(
+    const dynamic &obj) {
+  assign(id, obj, "id");
+  assign(origin, obj, "origin");
+  assign(name, obj, "name");
+  assign(auxData, obj, "auxData");
+  assign(isPageContext, obj, "isPageContext");
+  assign(isDefault, obj, "isDefault");
+}
+
+dynamic runtime::ExecutionContextDescription::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "id", id);
+  put(obj, "origin", origin);
+  put(obj, "name", name);
+  put(obj, "auxData", auxData);
+  put(obj, "isPageContext", isPageContext);
+  put(obj, "isDefault", isDefault);
+  return obj;
+}
+
+runtime::PropertyDescriptor::PropertyDescriptor(const dynamic &obj) {
+  assign(name, obj, "name");
+  assign(value, obj, "value");
+  assign(writable, obj, "writable");
+  assign(get, obj, "get");
+  assign(set, obj, "set");
+  assign(configurable, obj, "configurable");
+  assign(enumerable, obj, "enumerable");
+  assign(wasThrown, obj, "wasThrown");
+  assign(isOwn, obj, "isOwn");
+  assign(symbol, obj, "symbol");
+}
+
+dynamic runtime::PropertyDescriptor::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "name", name);
+  put(obj, "value", value);
+  put(obj, "writable", writable);
+  put(obj, "get", get);
+  put(obj, "set", set);
+  put(obj, "configurable", configurable);
+  put(obj, "enumerable", enumerable);
+  put(obj, "wasThrown", wasThrown);
+  put(obj, "isOwn", isOwn);
+  put(obj, "symbol", symbol);
+  return obj;
+}
+
+runtime::InternalPropertyDescriptor::InternalPropertyDescriptor(
+    const dynamic &obj) {
+  assign(name, obj, "name");
+  assign(value, obj, "value");
+}
+
+dynamic runtime::InternalPropertyDescriptor::toDynamic() const {
+  dynamic obj = dynamic::object;
+
+  put(obj, "name", name);
+  put(obj, "value", value);
+  return obj;
+}
+
+/// Requests
+UnknownRequest::UnknownRequest() {}
+
+UnknownRequest::UnknownRequest(const dynamic &obj) {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+  assign(params, obj, "params");
+}
+
+dynamic UnknownRequest::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  put(obj, "params", params);
+  return obj;
+}
+
+void UnknownRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::DisableRequest::DisableRequest() : Request("Debugger.disable") {}
+
+debugger::DisableRequest::DisableRequest(const dynamic &obj)
+    : Request("Debugger.disable") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+}
+
+dynamic debugger::DisableRequest::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  return obj;
+}
+
+void debugger::DisableRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::EnableRequest::EnableRequest() : Request("Debugger.enable") {}
+
+debugger::EnableRequest::EnableRequest(const dynamic &obj)
+    : Request("Debugger.enable") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+}
+
+dynamic debugger::EnableRequest::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  return obj;
+}
+
+void debugger::EnableRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::EvaluateOnCallFrameRequest::EvaluateOnCallFrameRequest()
+    : Request("Debugger.evaluateOnCallFrame") {}
+
+debugger::EvaluateOnCallFrameRequest::EvaluateOnCallFrameRequest(
+    const dynamic &obj)
+    : Request("Debugger.evaluateOnCallFrame") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(callFrameId, params, "callFrameId");
+  assign(expression, params, "expression");
+  assign(objectGroup, params, "objectGroup");
+  assign(includeCommandLineAPI, params, "includeCommandLineAPI");
+  assign(silent, params, "silent");
+  assign(returnByValue, params, "returnByValue");
+}
+
+dynamic debugger::EvaluateOnCallFrameRequest::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "callFrameId", callFrameId);
+  put(params, "expression", expression);
+  put(params, "objectGroup", objectGroup);
+  put(params, "includeCommandLineAPI", includeCommandLineAPI);
+  put(params, "silent", silent);
+  put(params, "returnByValue", returnByValue);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+void debugger::EvaluateOnCallFrameRequest::accept(
+    RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::PauseRequest::PauseRequest() : Request("Debugger.pause") {}
+
+debugger::PauseRequest::PauseRequest(const dynamic &obj)
+    : Request("Debugger.pause") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+}
+
+dynamic debugger::PauseRequest::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  return obj;
+}
+
+void debugger::PauseRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::RemoveBreakpointRequest::RemoveBreakpointRequest()
+    : Request("Debugger.removeBreakpoint") {}
+
+debugger::RemoveBreakpointRequest::RemoveBreakpointRequest(const dynamic &obj)
+    : Request("Debugger.removeBreakpoint") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(breakpointId, params, "breakpointId");
+}
+
+dynamic debugger::RemoveBreakpointRequest::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "breakpointId", breakpointId);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+void debugger::RemoveBreakpointRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::ResumeRequest::ResumeRequest() : Request("Debugger.resume") {}
+
+debugger::ResumeRequest::ResumeRequest(const dynamic &obj)
+    : Request("Debugger.resume") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+}
+
+dynamic debugger::ResumeRequest::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  return obj;
+}
+
+void debugger::ResumeRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::SetBreakpointByUrlRequest::SetBreakpointByUrlRequest()
+    : Request("Debugger.setBreakpointByUrl") {}
+
+debugger::SetBreakpointByUrlRequest::SetBreakpointByUrlRequest(
+    const dynamic &obj)
+    : Request("Debugger.setBreakpointByUrl") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(lineNumber, params, "lineNumber");
+  assign(url, params, "url");
+  assign(urlRegex, params, "urlRegex");
+  assign(columnNumber, params, "columnNumber");
+  assign(condition, params, "condition");
+}
+
+dynamic debugger::SetBreakpointByUrlRequest::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "lineNumber", lineNumber);
+  put(params, "url", url);
+  put(params, "urlRegex", urlRegex);
+  put(params, "columnNumber", columnNumber);
+  put(params, "condition", condition);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+void debugger::SetBreakpointByUrlRequest::accept(
+    RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::SetPauseOnExceptionsRequest::SetPauseOnExceptionsRequest()
+    : Request("Debugger.setPauseOnExceptions") {}
+
+debugger::SetPauseOnExceptionsRequest::SetPauseOnExceptionsRequest(
+    const dynamic &obj)
+    : Request("Debugger.setPauseOnExceptions") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(state, params, "state");
+}
+
+dynamic debugger::SetPauseOnExceptionsRequest::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "state", state);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+void debugger::SetPauseOnExceptionsRequest::accept(
+    RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::StepIntoRequest::StepIntoRequest() : Request("Debugger.stepInto") {}
+
+debugger::StepIntoRequest::StepIntoRequest(const dynamic &obj)
+    : Request("Debugger.stepInto") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+}
+
+dynamic debugger::StepIntoRequest::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  return obj;
+}
+
+void debugger::StepIntoRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::StepOutRequest::StepOutRequest() : Request("Debugger.stepOut") {}
+
+debugger::StepOutRequest::StepOutRequest(const dynamic &obj)
+    : Request("Debugger.stepOut") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+}
+
+dynamic debugger::StepOutRequest::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  return obj;
+}
+
+void debugger::StepOutRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+debugger::StepOverRequest::StepOverRequest() : Request("Debugger.stepOver") {}
+
+debugger::StepOverRequest::StepOverRequest(const dynamic &obj)
+    : Request("Debugger.stepOver") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+}
+
+dynamic debugger::StepOverRequest::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  return obj;
+}
+
+void debugger::StepOverRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+runtime::EvaluateRequest::EvaluateRequest() : Request("Runtime.evaluate") {}
+
+runtime::EvaluateRequest::EvaluateRequest(const dynamic &obj)
+    : Request("Runtime.evaluate") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(expression, params, "expression");
+  assign(objectGroup, params, "objectGroup");
+  assign(includeCommandLineAPI, params, "includeCommandLineAPI");
+  assign(silent, params, "silent");
+  assign(contextId, params, "contextId");
+  assign(returnByValue, params, "returnByValue");
+  assign(awaitPromise, params, "awaitPromise");
+}
+
+dynamic runtime::EvaluateRequest::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "expression", expression);
+  put(params, "objectGroup", objectGroup);
+  put(params, "includeCommandLineAPI", includeCommandLineAPI);
+  put(params, "silent", silent);
+  put(params, "contextId", contextId);
+  put(params, "returnByValue", returnByValue);
+  put(params, "awaitPromise", awaitPromise);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+void runtime::EvaluateRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+runtime::GetPropertiesRequest::GetPropertiesRequest()
+    : Request("Runtime.getProperties") {}
+
+runtime::GetPropertiesRequest::GetPropertiesRequest(const dynamic &obj)
+    : Request("Runtime.getProperties") {
+  assign(id, obj, "id");
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(objectId, params, "objectId");
+  assign(ownProperties, params, "ownProperties");
+}
+
+dynamic runtime::GetPropertiesRequest::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "objectId", objectId);
+  put(params, "ownProperties", ownProperties);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+void runtime::GetPropertiesRequest::accept(RequestHandler &handler) const {
+  handler.handle(*this);
+}
+
+/// Responses
+ErrorResponse::ErrorResponse(const dynamic &obj) {
+  assign(id, obj, "id");
+
+  dynamic error = obj.at("error");
+  assign(code, error, "code");
+  assign(message, error, "message");
+  assign(data, error, "data");
+}
+
+dynamic ErrorResponse::toDynamic() const {
+  dynamic error = dynamic::object;
+  put(error, "code", code);
+  put(error, "message", message);
+  put(error, "data", data);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "error", std::move(error));
+  return obj;
+}
+
+OkResponse::OkResponse(const dynamic &obj) {
+  assign(id, obj, "id");
+}
+
+dynamic OkResponse::toDynamic() const {
+  dynamic result = dynamic::object;
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "result", std::move(result));
+  return obj;
+}
+
+debugger::EvaluateOnCallFrameResponse::EvaluateOnCallFrameResponse(
+    const dynamic &obj) {
+  assign(id, obj, "id");
+
+  dynamic res = obj.at("result");
+  assign(result, res, "result");
+  assign(exceptionDetails, res, "exceptionDetails");
+}
+
+dynamic debugger::EvaluateOnCallFrameResponse::toDynamic() const {
+  dynamic res = dynamic::object;
+  put(res, "result", result);
+  put(res, "exceptionDetails", exceptionDetails);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "result", std::move(res));
+  return obj;
+}
+
+debugger::SetBreakpointByUrlResponse::SetBreakpointByUrlResponse(
+    const dynamic &obj) {
+  assign(id, obj, "id");
+
+  dynamic res = obj.at("result");
+  assign(breakpointId, res, "breakpointId");
+  assign(locations, res, "locations");
+}
+
+dynamic debugger::SetBreakpointByUrlResponse::toDynamic() const {
+  dynamic res = dynamic::object;
+  put(res, "breakpointId", breakpointId);
+  put(res, "locations", locations);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "result", std::move(res));
+  return obj;
+}
+
+runtime::EvaluateResponse::EvaluateResponse(const dynamic &obj) {
+  assign(id, obj, "id");
+
+  dynamic res = obj.at("result");
+  assign(result, res, "result");
+  assign(exceptionDetails, res, "exceptionDetails");
+}
+
+dynamic runtime::EvaluateResponse::toDynamic() const {
+  dynamic res = dynamic::object;
+  put(res, "result", result);
+  put(res, "exceptionDetails", exceptionDetails);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "result", std::move(res));
+  return obj;
+}
+
+runtime::GetPropertiesResponse::GetPropertiesResponse(const dynamic &obj) {
+  assign(id, obj, "id");
+
+  dynamic res = obj.at("result");
+  assign(result, res, "result");
+  assign(internalProperties, res, "internalProperties");
+  assign(exceptionDetails, res, "exceptionDetails");
+}
+
+dynamic runtime::GetPropertiesResponse::toDynamic() const {
+  dynamic res = dynamic::object;
+  put(res, "result", result);
+  put(res, "internalProperties", internalProperties);
+  put(res, "exceptionDetails", exceptionDetails);
+
+  dynamic obj = dynamic::object;
+  put(obj, "id", id);
+  put(obj, "result", std::move(res));
+  return obj;
+}
+
+/// Notifications
+debugger::BreakpointResolvedNotification::BreakpointResolvedNotification()
+    : Notification("Debugger.breakpointResolved") {}
+
+debugger::BreakpointResolvedNotification::BreakpointResolvedNotification(
+    const dynamic &obj)
+    : Notification("Debugger.breakpointResolved") {
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(breakpointId, params, "breakpointId");
+  assign(location, params, "location");
+}
+
+dynamic debugger::BreakpointResolvedNotification::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "breakpointId", breakpointId);
+  put(params, "location", location);
+
+  dynamic obj = dynamic::object;
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+debugger::PausedNotification::PausedNotification()
+    : Notification("Debugger.paused") {}
+
+debugger::PausedNotification::PausedNotification(const dynamic &obj)
+    : Notification("Debugger.paused") {
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(callFrames, params, "callFrames");
+  assign(reason, params, "reason");
+  assign(data, params, "data");
+  assign(hitBreakpoints, params, "hitBreakpoints");
+  assign(asyncStackTrace, params, "asyncStackTrace");
+}
+
+dynamic debugger::PausedNotification::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "callFrames", callFrames);
+  put(params, "reason", reason);
+  put(params, "data", data);
+  put(params, "hitBreakpoints", hitBreakpoints);
+  put(params, "asyncStackTrace", asyncStackTrace);
+
+  dynamic obj = dynamic::object;
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+debugger::ResumedNotification::ResumedNotification()
+    : Notification("Debugger.resumed") {}
+
+debugger::ResumedNotification::ResumedNotification(const dynamic &obj)
+    : Notification("Debugger.resumed") {
+  assign(method, obj, "method");
+}
+
+dynamic debugger::ResumedNotification::toDynamic() const {
+  dynamic obj = dynamic::object;
+  put(obj, "method", method);
+  return obj;
+}
+
+debugger::ScriptParsedNotification::ScriptParsedNotification()
+    : Notification("Debugger.scriptParsed") {}
+
+debugger::ScriptParsedNotification::ScriptParsedNotification(const dynamic &obj)
+    : Notification("Debugger.scriptParsed") {
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(scriptId, params, "scriptId");
+  assign(url, params, "url");
+  assign(startLine, params, "startLine");
+  assign(startColumn, params, "startColumn");
+  assign(endLine, params, "endLine");
+  assign(endColumn, params, "endColumn");
+  assign(executionContextId, params, "executionContextId");
+  assign(hash, params, "hash");
+  assign(executionContextAuxData, params, "executionContextAuxData");
+  assign(sourceMapURL, params, "sourceMapURL");
+}
+
+dynamic debugger::ScriptParsedNotification::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "scriptId", scriptId);
+  put(params, "url", url);
+  put(params, "startLine", startLine);
+  put(params, "startColumn", startColumn);
+  put(params, "endLine", endLine);
+  put(params, "endColumn", endColumn);
+  put(params, "executionContextId", executionContextId);
+  put(params, "hash", hash);
+  put(params, "executionContextAuxData", executionContextAuxData);
+  put(params, "sourceMapURL", sourceMapURL);
+
+  dynamic obj = dynamic::object;
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+runtime::ConsoleAPICalledNotification::ConsoleAPICalledNotification()
+    : Notification("Runtime.consoleAPICalled") {}
+
+runtime::ConsoleAPICalledNotification::ConsoleAPICalledNotification(
+    const dynamic &obj)
+    : Notification("Runtime.consoleAPICalled") {
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(type, params, "type");
+  assign(args, params, "args");
+  assign(executionContextId, params, "executionContextId");
+  assign(timestamp, params, "timestamp");
+  assign(stackTrace, params, "stackTrace");
+}
+
+dynamic runtime::ConsoleAPICalledNotification::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "type", type);
+  put(params, "args", args);
+  put(params, "executionContextId", executionContextId);
+  put(params, "timestamp", timestamp);
+  put(params, "stackTrace", stackTrace);
+
+  dynamic obj = dynamic::object;
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+runtime::ExecutionContextCreatedNotification::
+    ExecutionContextCreatedNotification()
+    : Notification("Runtime.executionContextCreated") {}
+
+runtime::ExecutionContextCreatedNotification::
+    ExecutionContextCreatedNotification(const dynamic &obj)
+    : Notification("Runtime.executionContextCreated") {
+  assign(method, obj, "method");
+
+  dynamic params = obj.at("params");
+  assign(context, params, "context");
+}
+
+dynamic runtime::ExecutionContextCreatedNotification::toDynamic() const {
+  dynamic params = dynamic::object;
+  put(params, "context", context);
+
+  dynamic obj = dynamic::object;
+  put(obj, "method", method);
+  put(obj, "params", std::move(params));
+  return obj;
+}
+
+} // namespace message
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/MessageTypes.h

@@ -0,0 +1,499 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+// @generated <<SignedSource::*O*zOeWoEQle#+L!plEphiEmie@IsG>>
+
+#pragma once
+
+#include <hermes/inspector/chrome/MessageInterfaces.h>
+
+#include <vector>
+
+#include <folly/Optional.h>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+namespace message {
+
+struct UnknownRequest;
+
+namespace debugger {
+using BreakpointId = std::string;
+struct BreakpointResolvedNotification;
+struct CallFrame;
+using CallFrameId = std::string;
+struct DisableRequest;
+struct EnableRequest;
+struct EvaluateOnCallFrameRequest;
+struct EvaluateOnCallFrameResponse;
+struct Location;
+struct PauseRequest;
+struct PausedNotification;
+struct RemoveBreakpointRequest;
+struct ResumeRequest;
+struct ResumedNotification;
+struct Scope;
+struct ScriptParsedNotification;
+struct SetBreakpointByUrlRequest;
+struct SetBreakpointByUrlResponse;
+struct SetPauseOnExceptionsRequest;
+struct StepIntoRequest;
+struct StepOutRequest;
+struct StepOverRequest;
+} // namespace debugger
+
+namespace runtime {
+struct CallFrame;
+struct ConsoleAPICalledNotification;
+struct EvaluateRequest;
+struct EvaluateResponse;
+struct ExceptionDetails;
+struct ExecutionContextCreatedNotification;
+struct ExecutionContextDescription;
+using ExecutionContextId = int;
+struct GetPropertiesRequest;
+struct GetPropertiesResponse;
+struct InternalPropertyDescriptor;
+struct PropertyDescriptor;
+struct RemoteObject;
+using RemoteObjectId = std::string;
+using ScriptId = std::string;
+struct StackTrace;
+using Timestamp = double;
+using UnserializableValue = std::string;
+} // namespace runtime
+
+/// RequestHandler handles requests via the visitor pattern.
+struct RequestHandler {
+  virtual ~RequestHandler() = default;
+
+  virtual void handle(const UnknownRequest &req) = 0;
+  virtual void handle(const debugger::DisableRequest &req) = 0;
+  virtual void handle(const debugger::EnableRequest &req) = 0;
+  virtual void handle(const debugger::EvaluateOnCallFrameRequest &req) = 0;
+  virtual void handle(const debugger::PauseRequest &req) = 0;
+  virtual void handle(const debugger::RemoveBreakpointRequest &req) = 0;
+  virtual void handle(const debugger::ResumeRequest &req) = 0;
+  virtual void handle(const debugger::SetBreakpointByUrlRequest &req) = 0;
+  virtual void handle(const debugger::SetPauseOnExceptionsRequest &req) = 0;
+  virtual void handle(const debugger::StepIntoRequest &req) = 0;
+  virtual void handle(const debugger::StepOutRequest &req) = 0;
+  virtual void handle(const debugger::StepOverRequest &req) = 0;
+  virtual void handle(const runtime::EvaluateRequest &req) = 0;
+  virtual void handle(const runtime::GetPropertiesRequest &req) = 0;
+};
+
+/// NoopRequestHandler can be subclassed to only handle some requests.
+struct NoopRequestHandler : public RequestHandler {
+  void handle(const UnknownRequest &req) override {}
+  void handle(const debugger::DisableRequest &req) override {}
+  void handle(const debugger::EnableRequest &req) override {}
+  void handle(const debugger::EvaluateOnCallFrameRequest &req) override {}
+  void handle(const debugger::PauseRequest &req) override {}
+  void handle(const debugger::RemoveBreakpointRequest &req) override {}
+  void handle(const debugger::ResumeRequest &req) override {}
+  void handle(const debugger::SetBreakpointByUrlRequest &req) override {}
+  void handle(const debugger::SetPauseOnExceptionsRequest &req) override {}
+  void handle(const debugger::StepIntoRequest &req) override {}
+  void handle(const debugger::StepOutRequest &req) override {}
+  void handle(const debugger::StepOverRequest &req) override {}
+  void handle(const runtime::EvaluateRequest &req) override {}
+  void handle(const runtime::GetPropertiesRequest &req) override {}
+};
+
+/// Types
+struct debugger::Location : public Serializable {
+  Location() = default;
+  explicit Location(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  runtime::ScriptId scriptId{};
+  int lineNumber{};
+  folly::Optional<int> columnNumber;
+};
+
+struct runtime::RemoteObject : public Serializable {
+  RemoteObject() = default;
+  explicit RemoteObject(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  std::string type;
+  folly::Optional<std::string> subtype;
+  folly::Optional<std::string> className;
+  folly::Optional<folly::dynamic> value;
+  folly::Optional<runtime::UnserializableValue> unserializableValue;
+  folly::Optional<std::string> description;
+  folly::Optional<runtime::RemoteObjectId> objectId;
+};
+
+struct runtime::CallFrame : public Serializable {
+  CallFrame() = default;
+  explicit CallFrame(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  std::string functionName;
+  runtime::ScriptId scriptId{};
+  std::string url;
+  int lineNumber{};
+  int columnNumber{};
+};
+
+struct runtime::StackTrace : public Serializable {
+  StackTrace() = default;
+  explicit StackTrace(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  folly::Optional<std::string> description;
+  std::vector<runtime::CallFrame> callFrames;
+  std::unique_ptr<runtime::StackTrace> parent;
+};
+
+struct runtime::ExceptionDetails : public Serializable {
+  ExceptionDetails() = default;
+  explicit ExceptionDetails(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  int exceptionId{};
+  std::string text;
+  int lineNumber{};
+  int columnNumber{};
+  folly::Optional<runtime::ScriptId> scriptId;
+  folly::Optional<std::string> url;
+  folly::Optional<runtime::StackTrace> stackTrace;
+  folly::Optional<runtime::RemoteObject> exception;
+  folly::Optional<runtime::ExecutionContextId> executionContextId;
+};
+
+struct debugger::Scope : public Serializable {
+  Scope() = default;
+  explicit Scope(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  std::string type;
+  runtime::RemoteObject object{};
+  folly::Optional<std::string> name;
+  folly::Optional<debugger::Location> startLocation;
+  folly::Optional<debugger::Location> endLocation;
+};
+
+struct debugger::CallFrame : public Serializable {
+  CallFrame() = default;
+  explicit CallFrame(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  debugger::CallFrameId callFrameId{};
+  std::string functionName;
+  debugger::Location location{};
+  std::string url;
+  std::vector<debugger::Scope> scopeChain;
+  runtime::RemoteObject thisObj{};
+  folly::Optional<runtime::RemoteObject> returnValue;
+};
+
+struct runtime::ExecutionContextDescription : public Serializable {
+  ExecutionContextDescription() = default;
+  explicit ExecutionContextDescription(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  runtime::ExecutionContextId id{};
+  std::string origin;
+  std::string name;
+  folly::Optional<folly::dynamic> auxData;
+  folly::Optional<bool> isPageContext;
+  folly::Optional<bool> isDefault;
+};
+
+struct runtime::PropertyDescriptor : public Serializable {
+  PropertyDescriptor() = default;
+  explicit PropertyDescriptor(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  std::string name;
+  folly::Optional<runtime::RemoteObject> value;
+  folly::Optional<bool> writable;
+  folly::Optional<runtime::RemoteObject> get;
+  folly::Optional<runtime::RemoteObject> set;
+  bool configurable{};
+  bool enumerable{};
+  folly::Optional<bool> wasThrown;
+  folly::Optional<bool> isOwn;
+  folly::Optional<runtime::RemoteObject> symbol;
+};
+
+struct runtime::InternalPropertyDescriptor : public Serializable {
+  InternalPropertyDescriptor() = default;
+  explicit InternalPropertyDescriptor(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  std::string name;
+  folly::Optional<runtime::RemoteObject> value;
+};
+
+/// Requests
+struct UnknownRequest : public Request {
+  UnknownRequest();
+  explicit UnknownRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+
+  folly::Optional<folly::dynamic> params;
+};
+
+struct debugger::DisableRequest : public Request {
+  DisableRequest();
+  explicit DisableRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+};
+
+struct debugger::EnableRequest : public Request {
+  EnableRequest();
+  explicit EnableRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+};
+
+struct debugger::EvaluateOnCallFrameRequest : public Request {
+  EvaluateOnCallFrameRequest();
+  explicit EvaluateOnCallFrameRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+
+  debugger::CallFrameId callFrameId{};
+  std::string expression;
+  folly::Optional<std::string> objectGroup;
+  folly::Optional<bool> includeCommandLineAPI;
+  folly::Optional<bool> silent;
+  folly::Optional<bool> returnByValue;
+};
+
+struct debugger::PauseRequest : public Request {
+  PauseRequest();
+  explicit PauseRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+};
+
+struct debugger::RemoveBreakpointRequest : public Request {
+  RemoveBreakpointRequest();
+  explicit RemoveBreakpointRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+
+  debugger::BreakpointId breakpointId{};
+};
+
+struct debugger::ResumeRequest : public Request {
+  ResumeRequest();
+  explicit ResumeRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+};
+
+struct debugger::SetBreakpointByUrlRequest : public Request {
+  SetBreakpointByUrlRequest();
+  explicit SetBreakpointByUrlRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+
+  int lineNumber{};
+  folly::Optional<std::string> url;
+  folly::Optional<std::string> urlRegex;
+  folly::Optional<int> columnNumber;
+  folly::Optional<std::string> condition;
+};
+
+struct debugger::SetPauseOnExceptionsRequest : public Request {
+  SetPauseOnExceptionsRequest();
+  explicit SetPauseOnExceptionsRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+
+  std::string state;
+};
+
+struct debugger::StepIntoRequest : public Request {
+  StepIntoRequest();
+  explicit StepIntoRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+};
+
+struct debugger::StepOutRequest : public Request {
+  StepOutRequest();
+  explicit StepOutRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+};
+
+struct debugger::StepOverRequest : public Request {
+  StepOverRequest();
+  explicit StepOverRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+};
+
+struct runtime::EvaluateRequest : public Request {
+  EvaluateRequest();
+  explicit EvaluateRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+
+  std::string expression;
+  folly::Optional<std::string> objectGroup;
+  folly::Optional<bool> includeCommandLineAPI;
+  folly::Optional<bool> silent;
+  folly::Optional<runtime::ExecutionContextId> contextId;
+  folly::Optional<bool> returnByValue;
+  folly::Optional<bool> awaitPromise;
+};
+
+struct runtime::GetPropertiesRequest : public Request {
+  GetPropertiesRequest();
+  explicit GetPropertiesRequest(const folly::dynamic &obj);
+
+  folly::dynamic toDynamic() const override;
+  void accept(RequestHandler &handler) const override;
+
+  runtime::RemoteObjectId objectId{};
+  folly::Optional<bool> ownProperties;
+};
+
+/// Responses
+struct ErrorResponse : public Response {
+  ErrorResponse() = default;
+  explicit ErrorResponse(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  int code;
+  std::string message;
+  folly::Optional<folly::dynamic> data;
+};
+
+struct OkResponse : public Response {
+  OkResponse() = default;
+  explicit OkResponse(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+};
+
+struct debugger::EvaluateOnCallFrameResponse : public Response {
+  EvaluateOnCallFrameResponse() = default;
+  explicit EvaluateOnCallFrameResponse(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  runtime::RemoteObject result{};
+  folly::Optional<runtime::ExceptionDetails> exceptionDetails;
+};
+
+struct debugger::SetBreakpointByUrlResponse : public Response {
+  SetBreakpointByUrlResponse() = default;
+  explicit SetBreakpointByUrlResponse(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  debugger::BreakpointId breakpointId{};
+  std::vector<debugger::Location> locations;
+};
+
+struct runtime::EvaluateResponse : public Response {
+  EvaluateResponse() = default;
+  explicit EvaluateResponse(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  runtime::RemoteObject result{};
+  folly::Optional<runtime::ExceptionDetails> exceptionDetails;
+};
+
+struct runtime::GetPropertiesResponse : public Response {
+  GetPropertiesResponse() = default;
+  explicit GetPropertiesResponse(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  std::vector<runtime::PropertyDescriptor> result;
+  folly::Optional<std::vector<runtime::InternalPropertyDescriptor>>
+      internalProperties;
+  folly::Optional<runtime::ExceptionDetails> exceptionDetails;
+};
+
+/// Notifications
+struct debugger::BreakpointResolvedNotification : public Notification {
+  BreakpointResolvedNotification();
+  explicit BreakpointResolvedNotification(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  debugger::BreakpointId breakpointId{};
+  debugger::Location location{};
+};
+
+struct debugger::PausedNotification : public Notification {
+  PausedNotification();
+  explicit PausedNotification(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  std::vector<debugger::CallFrame> callFrames;
+  std::string reason;
+  folly::Optional<folly::dynamic> data;
+  folly::Optional<std::vector<std::string>> hitBreakpoints;
+  folly::Optional<runtime::StackTrace> asyncStackTrace;
+};
+
+struct debugger::ResumedNotification : public Notification {
+  ResumedNotification();
+  explicit ResumedNotification(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+};
+
+struct debugger::ScriptParsedNotification : public Notification {
+  ScriptParsedNotification();
+  explicit ScriptParsedNotification(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  runtime::ScriptId scriptId{};
+  std::string url;
+  int startLine{};
+  int startColumn{};
+  int endLine{};
+  int endColumn{};
+  runtime::ExecutionContextId executionContextId{};
+  std::string hash;
+  folly::Optional<folly::dynamic> executionContextAuxData;
+  folly::Optional<std::string> sourceMapURL;
+};
+
+struct runtime::ConsoleAPICalledNotification : public Notification {
+  ConsoleAPICalledNotification();
+  explicit ConsoleAPICalledNotification(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  std::string type;
+  std::vector<runtime::RemoteObject> args;
+  runtime::ExecutionContextId executionContextId{};
+  runtime::Timestamp timestamp{};
+  folly::Optional<runtime::StackTrace> stackTrace;
+};
+
+struct runtime::ExecutionContextCreatedNotification : public Notification {
+  ExecutionContextCreatedNotification();
+  explicit ExecutionContextCreatedNotification(const folly::dynamic &obj);
+  folly::dynamic toDynamic() const override;
+
+  runtime::ExecutionContextDescription context{};
+};
+
+} // namespace message
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook

ReactCommon/hermes/inspector/chrome/MessageTypesInlines.h

@@ -0,0 +1,154 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#pragma once
+
+#include <hermes/inspector/chrome/MessageInterfaces.h>
+
+#include <memory>
+#include <type_traits>
+
+namespace facebook {
+namespace hermes {
+namespace inspector {
+namespace chrome {
+namespace message {
+
+using dynamic = folly::dynamic;
+
+template <typename T>
+using optional = folly::Optional<T>;
+
+template <typename>
+struct is_vector : std::false_type {};
+
+template <typename T>
+struct is_vector<std::vector<T>> : std::true_type {};
+
+/// valueFromDynamic
+
+template <typename T>
+typename std::enable_if<std::is_base_of<Serializable, T>::value, T>::type
+valueFromDynamic(const dynamic &obj) {
+  return T(obj);
+}
+
+template <typename T>
+typename std::enable_if<std::is_integral<T>::value, T>::type valueFromDynamic(
+    const dynamic &obj) {
+  return obj.asInt();
+}
+
+template <typename T>
+typename std::enable_if<std::is_floating_point<T>::value, T>::type
+valueFromDynamic(const dynamic &obj) {
+  return obj.asDouble();
+}
+
+template <typename T>
+typename std::enable_if<std::is_same<T, std::string>::value, T>::type
+valueFromDynamic(const dynamic &obj) {
+  return obj.asString();
+}
+
+template <typename T>
+typename std::enable_if<std::is_same<T, dynamic>::value, T>::type
+valueFromDynamic(const dynamic &obj) {
+  return obj;
+}
+
+template <typename T>
+typename std::enable_if<is_vector<T>::value, T>::type valueFromDynamic(
+    const dynamic &items) {
+  T result;
+  result.reserve(items.size());
+  for (const auto &item : items) {
+    result.push_back(valueFromDynamic<typename T::value_type>(item));
+  }
+  return result;
+}
+
+/// assign(lhs, obj, key) is a wrapper for:
+///
+///   lhs = obj[key]
+///
+/// It mainly exists so that we can choose the right version of valueFromDynamic
+/// based on the type of lhs.
+
+template <typename T, typename U>
+void assign(T &lhs, const dynamic &obj, const U &key) {
+  lhs = valueFromDynamic<T>(obj.at(key));
+}
+
+template <typename T, typename U>
+void assign(optional<T> &lhs, const dynamic &obj, const U &key) {
+  auto it = obj.find(key);
+  if (it != obj.items().end()) {
+    lhs = valueFromDynamic<T>(it->second);
+  } else {
+    lhs.clear();
+  }
+}
+
+template <typename T, typename U>
+void assign(std::unique_ptr<T> &lhs, const dynamic &obj, const U &key) {
+  auto it = obj.find(key);
+  if (it != obj.items().end()) {
+    lhs = std::make_unique<T>(valueFromDynamic<T>(it->second));
+  } else {
+    lhs.reset();
+  }
+}
+
+/// valueToDynamic
+
+inline dynamic valueToDynamic(const Serializable &value) {
+  return value.toDynamic();
+}
+
+template <typename T>
+typename std::enable_if<!std::is_base_of<Serializable, T>::value, dynamic>::type
+valueToDynamic(const T &item) {
+  return dynamic(item);
+}
+
+template <typename T>
+dynamic valueToDynamic(const std::vector<T> &items) {
+  dynamic result = dynamic::array;
+  for (const auto &item : items) {
+    result.push_back(valueToDynamic(item));
+  }
+  return result;
+}
+
+/// put(obj, key, value) is a wrapper for:
+///
+///   obj[key] = valueToDynamic(value);
+
+template <typename K, typename V>
+void put(dynamic &obj, const K &key, const V &value) {
+  obj[key] = valueToDynamic(value);
+}
+
+template <typename K, typename V>
+void put(dynamic &obj, const K &key, const optional<V> &optValue) {
+  if (optValue.hasValue()) {
+    obj[key] = valueToDynamic(optValue.value());
+  } else {
+    obj.erase(key);
+  }
+}
+
+template <typename K, typename V>
+void put(dynamic &obj, const K &key, const std::unique_ptr<V> &ptr) {
+  if (ptr.get()) {
+    obj[key] = valueToDynamic(*ptr);
+  } else {
+    obj.erase(key);
+  }
+}
+
+} // namespace message
+} // namespace chrome
+} // namespace inspector
+} // namespace hermes
+} // namespace facebook