packager: HMRBundle: @flow

Summary: Better to have *some* Flow coverage (I'd like 100% of packager covered from when we split it apart) than none.

Reviewed By: davidaurelio

Differential Revision: D5077757

fbshipit-source-id: b23169b3edf2bd3eb0e8a399d099151aa705b198

packages/metro-bundler/src/Bundler/BundleBase.js

@@ -28,18 +28,18 @@ class BundleBase {
   _assets: Array<mixed>;
   _finalized: boolean;
   _mainModuleId: number | void;
-  _modules: Array<ModuleTransport>;
   _source: ?string;
+  __modules: Array<ModuleTransport>;
 
   constructor() {
     this._finalized = false;
-    this._modules = [];
+    this.__modules = [];
     this._assets = [];
     this._mainModuleId = undefined;
   }
 
   isEmpty() {
-    return this._modules.length === 0 && this._assets.length === 0;
+    return this.__modules.length === 0 && this._assets.length === 0;
   }
 
   getMainModuleId() {
@@ -55,7 +55,7 @@ class BundleBase {
       throw new Error('Expected a ModuleTransport object');
     }
 
-    return this._modules.push(module) - 1;
+    return this.__modules.push(module) - 1;
   }
 
   replaceModuleAt(index: number, module: ModuleTransport) {
@@ -63,11 +63,11 @@ class BundleBase {
       throw new Error('Expeceted a ModuleTransport object');
     }
 
-    this._modules[index] = module;
+    this.__modules[index] = module;
   }
 
   getModules() {
-    return this._modules;
+    return this.__modules;
   }
 
   getAssets() {
@@ -80,7 +80,7 @@ class BundleBase {
 
   finalize(options: FinalizeOptions) {
     if (!options.allowUpdates) {
-      Object.freeze(this._modules);
+      Object.freeze(this.__modules);
       Object.freeze(this._assets);
     }
 
@@ -94,7 +94,7 @@ class BundleBase {
       return this._source;
     }
 
-    this._source = this._modules.map(module => module.code).join('\n');
+    this._source = this.__modules.map(module => module.code).join('\n');
     return this._source;
   }
 

packages/metro-bundler/src/Bundler/HMRBundle.js

@@ -5,14 +5,34 @@
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @flow
+ * @format
  */
+
 'use strict';
 
 const BundleBase = require('./BundleBase');
 const ModuleTransport = require('../lib/ModuleTransport');
 
+import type Resolver from '../Resolver';
+import type ResolutionResponse
+  from '../node-haste/DependencyGraph/ResolutionResponse';
+import type Module from '../node-haste/Module';
+
 class HMRBundle extends BundleBase {
-  constructor({sourceURLFn, sourceMappingURLFn}) {
+  _sourceMappingURLFn: (hmrpath: string) => mixed;
+  _sourceMappingURLs: Array<mixed>;
+  _sourceURLFn: (hmrpath: string) => mixed;
+  _sourceURLs: Array<mixed>;
+
+  constructor({
+    sourceURLFn,
+    sourceMappingURLFn,
+  }: {
+    sourceURLFn: (hmrpath: string) => mixed,
+    sourceMappingURLFn: (hmrpath: string) => mixed,
+  }) {
     super();
     this._sourceURLFn = sourceURLFn;
     this._sourceMappingURLFn = sourceMappingURLFn;
@@ -20,22 +40,35 @@ class HMRBundle extends BundleBase {
     this._sourceMappingURLs = [];
   }
 
-  addModule(resolver, response, module, moduleTransport) {
+  addModule(
+    /* $FlowFixMe: broken OOP design: function signature should be the same */
+    resolver: Resolver,
+    /* $FlowFixMe: broken OOP design: function signature should be the same */
+    response: ResolutionResponse<Module, {}>,
+    /* $FlowFixMe: broken OOP design: function signature should be the same */
+    module: Module,
+    /* $FlowFixMe: broken OOP design: function signature should be the same */
+    moduleTransport: ModuleTransport,
+  ) {
     const code = resolver.resolveRequires(
       response,
       module,
       moduleTransport.code,
+      /* $FlowFixMe: may not exist */
       moduleTransport.meta.dependencyOffsets,
     );
 
     super.addModule(new ModuleTransport({...moduleTransport, code}));
-    this._sourceMappingURLs.push(this._sourceMappingURLFn(moduleTransport.sourcePath));
+    this._sourceMappingURLs.push(
+      this._sourceMappingURLFn(moduleTransport.sourcePath),
+    );
     this._sourceURLs.push(this._sourceURLFn(moduleTransport.sourcePath));
-    return Promise.resolve();
+    // inconsistent with parent class return type
+    return (Promise.resolve(): any);
   }
 
   getModulesIdsAndCode() {
-    return this._modules.map(module => {
+    return this.__modules.map(module => {
       return {
         id: JSON.stringify(module.id),
         code: module.code,

packages/metro-bundler/src/Bundler/index.js

@@ -338,7 +338,7 @@ class Bundler {
     unbundle,
   }: {
     assetPlugins?: Array<string>,
-    bundle: Bundle,
+    bundle: Bundle | HMRBundle,
     dev: boolean,
     entryFile?: string,
     entryModuleOnly?: boolean,