From bf0806b8032e4d181874de695ea5807369cd7cfe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mart=C3=ADn=20Bigio?= <martinb@fb.com>
Date: Fri, 26 Feb 2016 15:14:47 -0800
Subject: [PATCH] Allow parents to accept children modules

Summary:In order to be able to Hot Load Redux stores and modules that export functions, we need to build infrastructure to bubble up the HMR updates similar to how webpack does: https://webpack.github.io/docs/hot-module-replacement-with-webpack.html.

In here we introduce the minimum of this infrastructure we need to make this work. The Packager server needs to send the inverse dependencies to the HMR runtime that runs on the client so that it can bubble up the patches if they cannot be self accepted by the module that was changed.

This diff relies on https://github.com/facebook/node-haste/pull/40/files which adds support for getting the inverse dependencies.

Reviewed By: davidaurelio

Differential Revision: D2950662

fb-gh-sync-id: 26dcd4aa15da76a727026a9d7ee06e7ae4d22eaa
shipit-source-id: 26dcd4aa15da76a727026a9d7ee06e7ae4d22eaa
---
 react-packager/src/Bundler/HMRBundle.js       | 12 +++--
 .../src/Resolver/polyfills/require.js         | 51 +++++++++++++++----
 2 files changed, 47 insertions(+), 16 deletions(-)

diff --git a/react-packager/src/Bundler/HMRBundle.js b/react-packager/src/Bundler/HMRBundle.js
index 49a21dfd..72850778 100644
--- a/react-packager/src/Bundler/HMRBundle.js
+++ b/react-packager/src/Bundler/HMRBundle.js
@@ -26,9 +26,6 @@ class HMRBundle extends BundleBase {
       module,
       transformed.code,
     ).then(({name, code}) => {
-      // need to be in single line so that lines match on sourcemaps
-      code = `__accept(${JSON.stringify(name)}, function(global, require, module, exports) { ${code} });`;
-
       const moduleTransport = new ModuleTransport({
         code,
         name,
@@ -44,8 +41,13 @@ class HMRBundle extends BundleBase {
     });
   }
 
-  getModulesCode() {
-    return this._modules.map(module => module.code);
+  getModulesNamesAndCode() {
+    return this._modules.map(module => {
+      return {
+        name: JSON.stringify(module.name),
+        code: module.code,
+      };
+    });
   }
 
   getSourceURLs() {
diff --git a/react-packager/src/Resolver/polyfills/require.js b/react-packager/src/Resolver/polyfills/require.js
index 764e4dd1..d5b0cd81 100644
--- a/react-packager/src/Resolver/polyfills/require.js
+++ b/react-packager/src/Resolver/polyfills/require.js
@@ -94,12 +94,12 @@ global.__d = define;
 global.require = require;
 
 if (__DEV__) { // HMR
-  function accept(id, factory) {
+  function accept(id, factory, inverseDependencies) {
     var mod = modules[id];
 
     if (!mod) {
       define(id, factory);
-      return; // new modules don't need to be accepted
+      return true; // new modules don't need to be accepted
     }
 
     if (!mod.module.hot) {
@@ -107,22 +107,51 @@ if (__DEV__) { // HMR
         'Cannot accept module because Hot Module Replacement ' +
         'API was not installed.'
       );
-      return;
+      return false;
     }
 
+    // replace and initialize factory
+    if (factory) {
+      mod.factory = factory;
+    }
+    mod.isInitialized = false;
+    require(id);
+
     if (mod.module.hot.acceptCallback) {
-      mod.factory = factory;
-      mod.isInitialized = false;
-      require(id);
-
       mod.module.hot.acceptCallback();
+      return true;
     } else {
-      console.warn(
-        '[HMR] Module `' + id + '` can\'t be hot reloaded because it\'s not a ' +
-        'React component. To get the changes reload the JS bundle.'
-      );
+      // need to have inverseDependencies to bubble up accept
+      if (!inverseDependencies) {
+        throw new Error('Undefined `inverseDependencies`');
+      }
+
+      // accept parent modules recursively up until all siblings are accepted
+      return acceptAll(inverseDependencies[id], inverseDependencies);
     }
   }
 
+  function acceptAll(modules, inverseDependencies) {
+    if (modules.length === 0) {
+      return true;
+    }
+
+    var notAccepted = modules.filter(function(module) {
+      return !accept(module, /*factory*/ undefined, inverseDependencies);
+    });
+
+    var parents = [];
+    for (var i = 0; i < notAccepted.length; i++) {
+      // if this the module has no parents then the change cannot be hot loaded
+      if (inverseDependencies[notAccepted[i]].length === 0) {
+        return false;
+      }
+
+      parents.pushAll(inverseDependencies[notAccepted[i]]);
+    }
+
+    return acceptAll(parents, inverseDependencies);
+  }
+
   global.__accept = accept;
 }