Make order of bundle transports deterministic

Summary:After starting to minify off the main process, the order of module transport objects in `Bundle` instances became less deterministic.
These changes guarantee that module transports appear in addition order, not in order of minification completion.

Reviewed By: bestander

Differential Revision: D3029588

fb-gh-sync-id: 80e83c05d7f78ed7e69583d7e3aa2831bd5ae4d0
shipit-source-id: 80e83c05d7f78ed7e69583d7e3aa2831bd5ae4d0

packager/react-packager/src/Bundler/Bundle.js

@@ -31,6 +31,7 @@ class Bundle extends BundleBase {
   }
 
   addModule(resolver, resolutionResponse, module, moduleTransport) {
+    const index = super.addModule(moduleTransport);
     return resolver.wrapModule({
       resolutionResponse,
       module,
@@ -46,7 +47,8 @@ class Bundle extends BundleBase {
         this._shouldCombineSourceMaps = true;
       }
 
-      super.addModule(new ModuleTransport({...moduleTransport, code, map}));
+      this.replaceModuleAt(
+        index, new ModuleTransport({...moduleTransport, code, map}));
     });
   }
 

packager/react-packager/src/Bundler/BundleBase.js

@@ -31,11 +31,19 @@ class BundleBase {
   }
 
   addModule(module) {
-    if (!module instanceof ModuleTransport) {
+    if (!(module instanceof ModuleTransport)) {
       throw new Error('Expeceted a ModuleTransport object');
     }
 
-    this._modules.push(module);
+    return this._modules.push(module) - 1;
+  }
+
+  replaceModuleAt(index, module) {
+    if (!(module instanceof ModuleTransport)) {
+      throw new Error('Expeceted a ModuleTransport object');
+    }
+
+    this._modules[index] = module;
   }
 
   getModules() {

packager/react-packager/src/Bundler/__tests__/Bundle-test.js

@@ -11,6 +11,7 @@
 jest.autoMockOff();
 
 const Bundle = require('../Bundle');
+const ModuleTransport = require('../../lib/ModuleTransport');
 const Promise = require('Promise');
 const SourceMapGenerator = require('source-map').SourceMapGenerator;
 const crypto = require('crypto');
@@ -106,6 +107,35 @@ describe('Bundle', () => {
         ].join('\n'));
       });
     });
+
+    fpit('should insert modules in a deterministic order, independent from timing of the wrapping process', () => {
+      const moduleTransports = [
+        createModuleTransport({name: 'module1'}),
+        createModuleTransport({name: 'module2'}),
+        createModuleTransport({name: 'module3'}),
+      ];
+
+      const resolves = {};
+      const resolver = {
+        wrapModule({name}) {
+          return new Promise(resolve => resolves[name] = resolve);
+        }
+      };
+
+      console.log(bundle.addModule+'')
+      const promise = Promise.all(
+        moduleTransports.map(m => bundle.addModule(resolver, null, null, m)))
+      .then(() => {
+        expect(bundle.getModules())
+          .toEqual(moduleTransports);
+      });
+
+      resolves.module2({code: ''});
+      resolves.module3({code: ''});
+      resolves.module1({code: ''});
+
+      return promise;
+    });
   });
 
   describe('sourcemap bundle', () => {
@@ -351,6 +381,15 @@ function addModule({bundle, code, sourceCode, sourcePath, map, virtual}) {
     resolverFor(code, map),
     null,
     null,
-    {code, sourceCode, sourcePath, map, virtual}
+    createModuleTransport({code, sourceCode, sourcePath, map, virtual})
   );
 }
+
+function createModuleTransport(data) {
+  return new ModuleTransport({
+    code: '',
+    sourceCode: '',
+    sourcePath: '',
+    ...data,
+  });
+}