From 37ff892e24864b4fe026130b6254c490cdaceecb Mon Sep 17 00:00:00 2001
From: Emily Janzer <janzer@fb.com>
Date: Tue, 17 Dec 2019 18:28:16 -0800
Subject: [PATCH] Backwards-compatible implementation for
 registerCallableModule

Summary:
We currently use `BatchedBridge.registerCallableModule` to call JS from platform code in a bunch of places (e.g. `RCTDeviceEventEmitter.emit()`), including some pretty essential ones - for example, Networking relies on `RCTDeviceEventEmitter` to emit events to JS for network requests and errors. In order to make the migration to bridgeless mode as easy as possible, it'd be best if we didn't have to update all the callsites in JS and platform code, at least for core JS modules like `RCTDeviceEventEmitter`. So we'd like to implement this callable module pattern for bridgeless mode as well.

In this diff, I'm installing a global variable, `RN$registerCallableModule`, which will store the JS module name and factory function in C++. This can then be called from platform code (Java/Obj-C) to invoke a JS function on a module using the existing APIs (`context.getJSModule()` on Android, `enqueueJSCall()` or similar on iOS).

Changelog: [Internal]

Reviewed By: PeteTheHeat

Differential Revision: D18798852

fbshipit-source-id: fbe9eaecaf6f5cab5173beec999d3a933b13375d
---
 Libraries/Core/setUpBatchedBridge.js | 77 +++++++++++-----------------
 1 file changed, 31 insertions(+), 46 deletions(-)

diff --git a/Libraries/Core/setUpBatchedBridge.js b/Libraries/Core/setUpBatchedBridge.js
index 8f6db0ec2f1..d718f3c8355 100644
--- a/Libraries/Core/setUpBatchedBridge.js
+++ b/Libraries/Core/setUpBatchedBridge.js
@@ -10,52 +10,37 @@
 
 'use strict';
 
-/**
- * We don't set up the batched bridge in bridgeless mode. Once we've migrated
- * everything over to bridgeless we can just delete this file.
- */
-if (!global.RN$Bridgeless) {
-  /**
-   * Set up the BatchedBridge. This must be done after the other steps in
-   * InitializeCore to ensure that the JS environment has been initialized.
-   * You can use this module directly, or just require InitializeCore.
-   */
+let registerModule;
+if (global.RN$Bridgeless && global.RN$registerCallableModule) {
+  registerModule = global.RN$registerCallableModule;
+} else {
   const BatchedBridge = require('../BatchedBridge/BatchedBridge');
-  BatchedBridge.registerLazyCallableModule('Systrace', () =>
-    require('../Performance/Systrace'),
-  );
-  BatchedBridge.registerLazyCallableModule('JSTimers', () =>
-    require('./Timers/JSTimers'),
-  );
-  BatchedBridge.registerLazyCallableModule('HeapCapture', () =>
-    require('../HeapCapture/HeapCapture'),
-  );
-  BatchedBridge.registerLazyCallableModule('SamplingProfiler', () =>
-    require('../Performance/SamplingProfiler'),
-  );
-  BatchedBridge.registerLazyCallableModule('RCTLog', () =>
-    require('../Utilities/RCTLog'),
-  );
-  BatchedBridge.registerLazyCallableModule('RCTDeviceEventEmitter', () =>
-    require('../EventEmitter/RCTDeviceEventEmitter'),
-  );
-  BatchedBridge.registerLazyCallableModule('RCTNativeAppEventEmitter', () =>
-    require('../EventEmitter/RCTNativeAppEventEmitter'),
-  );
-  BatchedBridge.registerLazyCallableModule('GlobalPerformanceLogger', () =>
-    require('../Utilities/GlobalPerformanceLogger'),
-  );
-  BatchedBridge.registerLazyCallableModule('JSDevSupportModule', () =>
-    require('../Utilities/JSDevSupportModule'),
-  );
+  registerModule = (moduleName, factory) =>
+    BatchedBridge.registerLazyCallableModule(moduleName, factory);
+}
 
-  if (__DEV__ && !global.__RCTProfileIsProfiling) {
-    BatchedBridge.registerLazyCallableModule('HMRClient', () =>
-      require('../Utilities/HMRClient'),
-    );
-  } else {
-    BatchedBridge.registerLazyCallableModule('HMRClient', () =>
-      require('../Utilities/HMRClientProdShim'),
-    );
-  }
+registerModule('Systrace', () => require('../Performance/Systrace'));
+registerModule('JSTimers', () => require('./Timers/JSTimers'));
+registerModule('HeapCapture', () => require('../HeapCapture/HeapCapture'));
+registerModule('SamplingProfiler', () =>
+  require('../Performance/SamplingProfiler'),
+);
+registerModule('RCTLog', () => require('../Utilities/RCTLog'));
+registerModule('RCTDeviceEventEmitter', () =>
+  require('../EventEmitter/RCTDeviceEventEmitter'),
+);
+registerModule('RCTNativeAppEventEmitter', () =>
+  require('../EventEmitter/RCTNativeAppEventEmitter'),
+);
+registerModule('GlobalPerformanceLogger', () =>
+  require('../Utilities/GlobalPerformanceLogger'),
+);
+registerModule('JSDevSupportModule', () =>
+  require('../Utilities/JSDevSupportModule'),
+);
+
+if (__DEV__ && !global.__RCTProfileIsProfiling) {
+  registerModule('HMRClient', () => require('../Utilities/HMRClient'));
+} else {
+  registerModule('HMRClient', () => require('../Utilities/HMRClientProdShim'));
 }