Improve constant inlining, add `process.platform`

Reviewed By: bestander

Differential Revision: D3235716

fb-gh-sync-id: f9019ec0042827e409fa84ba74f4c426ccad1519
fbshipit-source-id: f9019ec0042827e409fa84ba74f4c426ccad1519

Libraries/JavaScriptAppEngine/Initialization/InitializeJavaScriptAppEngine.js

@@ -81,7 +81,7 @@ function polyfillLazyGlobal(name, valueFn, scope = GLOBAL) {
     configurable: true,
     enumerable: true,
     get() {
-      return this[name] = valueFn();
+      return (this[name] = valueFn());
     },
     set(value) {
       Object.defineProperty(this, name, {
@@ -199,12 +199,14 @@ function setUpProfile() {
   }
 }
 
-function setUpProcessEnv() {
+function setUpProcess() {
   GLOBAL.process = GLOBAL.process || {};
   GLOBAL.process.env = GLOBAL.process.env || {};
   if (!GLOBAL.process.env.NODE_ENV) {
     GLOBAL.process.env.NODE_ENV = __DEV__ ? 'development' : 'production';
   }
+
+  polyfillLazyGlobal('platform', () => require('Platform').OS, GLOBAL.process);
 }
 
 function setUpDevTools() {
@@ -217,7 +219,7 @@ function setUpDevTools() {
   }
 }
 
-setUpProcessEnv();
+setUpProcess();
 setUpConsole();
 setUpTimers();
 setUpAlert();

packager/react-packager/src/JSTransformer/worker/__tests__/inline-test.js

@@ -35,7 +35,7 @@ describe('inline constants', () => {
       var a = __DEV__ ? 1 : 2;
       var b = a.__DEV__;
       var c = function __DEV__(__DEV__) {};
-    }`
+    }`;
     const {ast} = inline('arbitrary.js', {code}, {dev: true});
     expect(toString(ast)).toEqual(normalize(code.replace(/__DEV__/, 'true')));
   });
@@ -44,7 +44,7 @@ describe('inline constants', () => {
     const code = `function a() {
       var a = Platform.OS;
       var b = a.Platform.OS;
-    }`
+    }`;
     const {ast} = inline('arbitrary.js', {code}, {platform: 'ios'});
     expect(toString(ast)).toEqual(normalize(code.replace(/Platform\.OS/, '"ios"')));
   });
@@ -55,7 +55,18 @@ describe('inline constants', () => {
       function a() {
         if (Platform.OS === 'android') a = function() {};
         var b = a.Platform.OS;
-      }`
+      }`;
+    const {ast} = inline('arbitrary.js', {code}, {platform: 'ios'});
+    expect(toString(ast)).toEqual(normalize(code.replace(/Platform\.OS/, '"ios"')));
+  });
+
+  it('replaces Platform.OS in the code if Platform is a top level import from react-native', () => {
+    const code = `
+      var Platform = require('react-native').Platform;
+      function a() {
+        if (Platform.OS === 'android') a = function() {};
+        var b = a.Platform.OS;
+      }`;
     const {ast} = inline('arbitrary.js', {code}, {platform: 'ios'});
     expect(toString(ast)).toEqual(normalize(code.replace(/Platform\.OS/, '"ios"')));
   });
@@ -64,7 +75,7 @@ describe('inline constants', () => {
     const code = `function a() {
       var a = require('Platform').OS;
       var b = a.require('Platform').OS;
-    }`
+    }`;
     const {ast} = inline('arbitrary.js', {code}, {platform: 'android'});
     expect(toString(ast)).toEqual(
       normalize(code.replace(/require\('Platform'\)\.OS/, '"android"')));
@@ -74,18 +85,27 @@ describe('inline constants', () => {
     const code = `function a() {
       var a = React.Platform.OS;
       var b = a.React.Platform.OS;
-    }`
+    }`;
     const {ast} = inline('arbitrary.js', {code}, {platform: 'ios'});
     expect(toString(ast)).toEqual(normalize(code.replace(/React\.Platform\.OS/, '"ios"')));
   });
 
+  it('replaces ReactNative.Platform.OS in the code if ReactNative is a global', () => {
+    const code = `function a() {
+      var a = ReactNative.Platform.OS;
+      var b = a.ReactNative.Platform.OS;
+    }`;
+    const {ast} = inline('arbitrary.js', {code}, {platform: 'ios'});
+    expect(toString(ast)).toEqual(normalize(code.replace(/ReactNative\.Platform\.OS/, '"ios"')));
+  });
+
   it('replaces React.Platform.OS in the code if React is a top level import', () => {
     const code = `
       var React = require('React');
       function a() {
         if (React.Platform.OS === 'android') a = function() {};
         var b = a.React.Platform.OS;
-      }`
+      }`;
     const {ast} = inline('arbitrary.js', {code}, {platform: 'ios'});
     expect(toString(ast)).toEqual(normalize(code.replace(/React.Platform\.OS/, '"ios"')));
   });
@@ -94,19 +114,40 @@ describe('inline constants', () => {
     const code = `function a() {
       var a = require('React').Platform.OS;
       var b = a.require('React').Platform.OS;
-    }`
+    }`;
     const {ast} = inline('arbitrary.js', {code}, {platform: 'android'});
     expect(toString(ast)).toEqual(
       normalize(code.replace(/require\('React'\)\.Platform\.OS/, '"android"')));
   });
 
+  it('replaces ReactNative.Platform.OS in the code if ReactNative is a top level import', () => {
+    const code = `
+      var ReactNative = require('react-native');
+      function a() {
+        if (ReactNative.Platform.OS === 'android') a = function() {};
+        var b = a.ReactNative.Platform.OS;
+      }`;
+    const {ast} = inline('arbitrary.js', {code}, {platform: 'android'});
+    expect(toString(ast)).toEqual(normalize(code.replace(/ReactNative.Platform\.OS/, '"android"')));
+  });
+
+  it('replaces require("react-native").Platform.OS in the code', () => {
+    const code = `function a() {
+      var a = require('react-native').Platform.OS;
+      var b = a.require('react-native').Platform.OS;
+    }`;
+    const {ast} = inline('arbitrary.js', {code}, {platform: 'android'});
+    expect(toString(ast)).toEqual(
+      normalize(code.replace(/require\('react-native'\)\.Platform\.OS/, '"android"')));
+  });
+
   it('replaces process.env.NODE_ENV in the code', () => {
     const code = `function a() {
       if (process.env.NODE_ENV === 'production') {
         return require('Prod');
       }
       return require('Dev');
-    }`
+    }`;
     const {ast} = inline('arbitrary.js', {code}, {dev: false});
     expect(toString(ast)).toEqual(
       normalize(code.replace(/process\.env\.NODE_ENV/, '"production"')));
@@ -118,16 +159,28 @@ describe('inline constants', () => {
         return require('Prod');
       }
       return require('Dev');
-    }`
+    }`;
     const {ast} = inline('arbitrary.js', {code}, {dev: true});
     expect(toString(ast)).toEqual(
       normalize(code.replace(/process\.env\.NODE_ENV/, '"development"')));
   });
 
+  it('replaces process.platform in the code', () => {
+    const code = `function a() {
+      if (process.platform === 'android') {
+        return require('./android');
+      }
+      return require('./ios');
+    }`;
+    const {ast} = inline('arbitrary.js', {code}, {platform: 'ios'});
+    expect(toString(ast)).toEqual(
+      normalize(code.replace(/process\.platform\b/, '"ios"')));
+  });
+
   it('accepts an AST as input', function() {
-    const code = `function ifDev(a,b){return __DEV__?a:b;}`;
+    const code = 'function ifDev(a,b){return __DEV__?a:b;}';
     const {ast} = inline('arbitrary.hs', {ast: toAst(code)}, {dev: false});
-    expect(toString(ast)).toEqual(code.replace(/__DEV__/, 'false'))
+    expect(toString(ast)).toEqual(code.replace(/__DEV__/, 'false'));
   });
 });
 

packager/react-packager/src/JSTransformer/worker/inline.js

@@ -11,7 +11,8 @@
 const babel = require('babel-core');
 const t = babel.types;
 
-const react = {name: 'React'};
+const React = {name: 'React'};
+const ReactNative = {name: 'ReactNative'};
 const platform = {name: 'Platform'};
 const os = {name: 'OS'};
 const requirePattern = {name: 'require'};
@@ -19,9 +20,12 @@ const requirePattern = {name: 'require'};
 const env = {name: 'env'};
 const nodeEnv = {name: 'NODE_ENV'};
 const processId = {name: 'process'};
+const platformId = {name: 'platform'};
 
 const dev = {name: '__DEV__'};
 
+const importMap = new Map([['ReactNative', 'react-native']]);
+
 const isGlobal = (binding) => !binding;
 
 const isToplevelBinding = (binding) => isGlobal(binding) || !binding.scope.parent;
@@ -31,20 +35,27 @@ const isRequireCall = (node, dependencyId, scope) =>
   t.isIdentifier(node.callee, requirePattern) &&
   t.isStringLiteral(node.arguments[0], t.stringLiteral(dependencyId));
 
-const isImport = (node, scope, pattern) =>
-  t.isIdentifier(node, pattern) &&
-  isToplevelBinding(scope.getBinding(pattern.name)) ||
-  isRequireCall(node, pattern.name, scope);
+const isImport = (node, scope, patterns) =>
+  patterns.some(pattern => {
+    const importName = importMap.get(pattern.name) || pattern.name;
+    return isRequireCall(node, importName, scope);
+  });
+
+function isImportOrGlobal(node, scope, patterns) {
+  const identifier = patterns.find(pattern => t.isIdentifier(node, pattern));
+  return identifier && isToplevelBinding(scope.getBinding(identifier.name)) ||
+         isImport(node, scope, patterns);
+}
 
 const isPlatformOS = (node, scope) =>
   t.isIdentifier(node.property, os) &&
-  isImport(node.object, scope, platform);
+  isImportOrGlobal(node.object, scope, [platform]);
 
 const isReactPlatformOS = (node, scope) =>
   t.isIdentifier(node.property, os) &&
   t.isMemberExpression(node.object) &&
   t.isIdentifier(node.object.property, platform) &&
-  isImport(node.object.object, scope, react);
+  isImportOrGlobal(node.object.object, scope, [React, ReactNative]);
 
 const isProcessEnvNodeEnv = (node, scope) =>
   t.isIdentifier(node.property, nodeEnv) &&
@@ -53,6 +64,11 @@ const isProcessEnvNodeEnv = (node, scope) =>
   t.isIdentifier(node.object.object, processId) &&
   isGlobal(scope.getBinding(processId.name));
 
+const isProcessPlatform = (node, scope) =>
+  t.isIdentifier(node.property, platformId) &&
+  t.isIdentifier(node.object, processId) &&
+  isGlobal(scope.getBinding(processId.name));
+
 const isDev = (node, parent, scope) =>
   t.isIdentifier(node, dev) &&
   isGlobal(scope.getBinding(dev.name)) &&
@@ -71,11 +87,12 @@ const inlinePlugin = {
 
       if (isPlatformOS(node, scope) || isReactPlatformOS(node, scope)) {
         path.replaceWith(t.stringLiteral(state.opts.platform));
-      }
-
-      if(isProcessEnvNodeEnv(node, scope)) {
+      } else if (isProcessEnvNodeEnv(node, scope)) {
         path.replaceWith(
           t.stringLiteral(state.opts.dev ? 'development' : 'production'));
+      } else if (isProcessPlatform(node, scope)) {
+        path.replaceWith(
+          t.stringLiteral(state.opts.platform));
       }
     },
   },