From 1ebffa59fe1c465bf10441334c2e60e7a76b32c2 Mon Sep 17 00:00:00 2001
From: Dan Abramov <dan.abramov@gmail.com>
Date: Fri, 22 Apr 2016 02:42:29 +0100
Subject: [PATCH] ReactComponentTreeDevtool should ignore TopLevelWrapper

---
 src/isomorphic/ReactDebugTool.js              |  3 +
 .../devtools/ReactComponentTreeDevtool.js     | 78 +++++++++++--------
 .../ReactComponentTreeDevtool-test.js         | 24 +++++-
 src/renderers/dom/client/ReactMount.js        |  6 ++
 4 files changed, 73 insertions(+), 38 deletions(-)

diff --git a/src/isomorphic/ReactDebugTool.js b/src/isomorphic/ReactDebugTool.js
index 6dfd605b0b..8c45afedc2 100644
--- a/src/isomorphic/ReactDebugTool.js
+++ b/src/isomorphic/ReactDebugTool.js
@@ -58,6 +58,9 @@ var ReactDebugTool = {
   onSetState() {
     emitEvent('onSetState');
   },
+  onSetIsTopLevelWrapper(debugID, isTopLevelWrapper) {
+    emitEvent('onSetIsTopLevelWrapper', debugID, isTopLevelWrapper);
+  },
   onSetIsComposite(debugID, isComposite) {
     emitEvent('onSetIsComposite', debugID, isComposite);
   },
diff --git a/src/isomorphic/devtools/ReactComponentTreeDevtool.js b/src/isomorphic/devtools/ReactComponentTreeDevtool.js
index 0f65e1cfc2..fc30ffbbdb 100644
--- a/src/isomorphic/devtools/ReactComponentTreeDevtool.js
+++ b/src/isomorphic/devtools/ReactComponentTreeDevtool.js
@@ -13,11 +13,15 @@
 
 var invariant = require('invariant');
 
+var isTopLevelWrapperByID = {};
 var unmountedContainerIDs = [];
 var allChildIDsByContainerID = {};
 var tree = {};
 
 function updateTree(id, update) {
+  if (isTopLevelWrapperByID[id]) {
+    return;
+  }
   if (!tree[id]) {
     tree[id] = {};
   }
@@ -44,6 +48,13 @@ function purgeTree(id) {
 }
 
 var ReactComponentTreeDevtool = {
+  onSetIsTopLevelWrapper(id, isTopLevelWrapper) {
+    if (isTopLevelWrapper) {
+      delete tree[id];
+      isTopLevelWrapperByID[id] = true;
+    }
+  },
+
   onSetIsComposite(id, isComposite) {
     updateTree(id, item => item.isComposite = isComposite);
   },
@@ -53,45 +64,44 @@ var ReactComponentTreeDevtool = {
   },
 
   onSetChildren(id, nextChildIDs) {
-    var prevChildIDs;
     updateTree(id, item => {
-      prevChildIDs = item.childIDs || [];
+      var prevChildIDs = item.childIDs || [];
       item.childIDs = nextChildIDs;
-    });
 
-    prevChildIDs.forEach(prevChildID => {
-      if (tree[prevChildID] && nextChildIDs.indexOf(prevChildID) === -1) {
-        tree[prevChildID].parentID = null;
-      }
-    });
+      prevChildIDs.forEach(prevChildID => {
+        var prevChild = tree[prevChildID];
+        if (prevChild && nextChildIDs.indexOf(prevChildID) === -1) {
+          prevChild.parentID = null;
+        }
+      });
 
-    nextChildIDs.forEach(nextChildID => {
-      var item = tree[nextChildID];
+      nextChildIDs.forEach(nextChildID => {
+        var nextChild = tree[nextChildID];
+        invariant(
+          nextChild,
+          'Expected devtool events to fire for the child ' +
+          'before its parent includes it in onSetChildren().'
+        );
+        invariant(
+          nextChild.isComposite != null,
+          'Expected onSetIsComposite() to fire for the child ' +
+          'before its parent includes it in onSetChildren().'
+        );
+        invariant(
+          nextChild.displayName != null,
+          'Expected onSetDisplayName() to fire for the child ' +
+          'before its parent includes it in onSetChildren().'
+        );
+        invariant(
+          nextChild.childIDs != null || nextChild.text != null,
+          'Expected either onSetChildren() or onSetText() to fire for the child ' +
+          'before its parent includes it in onSetChildren().'
+        );
 
-      invariant(
-        item,
-        'Expected devtool events to fire for the child ' +
-        'before its parent includes it in onSetChildren().'
-      );
-      invariant(
-        item.isComposite != null,
-        'Expected onSetIsComposite() to fire for the child ' +
-        'before its parent includes it in onSetChildren().'
-      );
-      invariant(
-        item.displayName != null,
-        'Expected onSetDisplayName() to fire for the child ' +
-        'before its parent includes it in onSetChildren().'
-      );
-      invariant(
-        item.childIDs != null || item.text != null,
-        'Expected either onSetChildren() or onSetText() to fire for the child ' +
-        'before its parent includes it in onSetChildren().'
-      );
-
-      if (tree[nextChildID] && prevChildIDs.indexOf(nextChildID) === -1) {
-        tree[nextChildID].parentID = id;
-      }
+        if (prevChildIDs.indexOf(nextChildID) === -1) {
+          nextChild.parentID = id;
+        }
+      });
     });
   },
 
diff --git a/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.js b/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.js
index ced1b0f411..f8f8a8c4da 100644
--- a/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.js
+++ b/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.js
@@ -36,7 +36,7 @@ describe('ReactComponentTreeDevtool', () => {
     ReactDebugTool.removeDevtool(ReactComponentTreeDevtool);
   });
 
-  function denormalizeTree(
+  function explodeTree(
     tree,
     rootID,
     includeOwner = false,
@@ -54,7 +54,7 @@ describe('ReactComponentTreeDevtool', () => {
 
     if (item.childIDs) {
       result.children = item.childIDs.map(childID =>
-        denormalizeTree(tree, childID, includeOwner, rootID)
+        explodeTree(tree, childID, includeOwner, rootID)
       );
     }
     if (item.text != null) {
@@ -89,7 +89,7 @@ describe('ReactComponentTreeDevtool', () => {
     pairs.forEach(([element, expectedTree]) => {
       currentElement = element;
       ReactDOM.render(<Wrapper />, node);
-      expect(denormalizeTree(
+      expect(explodeTree(
         ReactComponentTreeDevtool.getTree(),
         rootInstance._renderedComponent._debugID,
         includeOwner
@@ -103,7 +103,7 @@ describe('ReactComponentTreeDevtool', () => {
     pairs.forEach(([element, expectedTree]) => {
       currentElement = element;
       ReactDOMServer.renderToString(<Wrapper />);
-      expect(denormalizeTree(
+      expect(explodeTree(
         ReactComponentTreeDevtool.getTree(),
         rootInstance._renderedComponent._debugID,
         includeOwner
@@ -1831,4 +1831,20 @@ describe('ReactComponentTreeDevtool', () => {
     };
     assertTreeMatches([element, tree], true);
   });
+
+  it('ignores top-level wrapper', () => {
+    var node = document.createElement('div');
+    ReactDOM.render(<div className="a" />, node);
+    expect(
+      getRegisteredDisplayNames(ReactComponentTreeDevtool.getTree())
+    ).toEqual(['div']);
+    ReactDOM.render(<div className="b" />, node);
+    expect(
+      getRegisteredDisplayNames(ReactComponentTreeDevtool.getTree())
+    ).toEqual(['div']);
+    ReactDOM.unmountComponentAtNode(node);
+    expect(
+      getRegisteredDisplayNames(ReactComponentTreeDevtool.getTree())
+    ).toEqual([]);
+  });
 });
diff --git a/src/renderers/dom/client/ReactMount.js b/src/renderers/dom/client/ReactMount.js
index bb6705ba15..87c9e1489a 100644
--- a/src/renderers/dom/client/ReactMount.js
+++ b/src/renderers/dom/client/ReactMount.js
@@ -332,6 +332,12 @@ var ReactMount = {
 
     ReactBrowserEventEmitter.ensureScrollValueMonitoring();
     var componentInstance = instantiateReactComponent(nextElement);
+    if (__DEV__) {
+      ReactInstrumentation.debugTool.onSetIsTopLevelWrapper(
+        componentInstance._debugID,
+        true
+      );
+    }
 
     // The initial render is synchronous but any updates that happen during
     // rendering, in componentWillMount or componentDidMount, will be batched