Add new worker for code transform, optimization, and dependency extra…

…ction

Summary:This adds a new worker implementation that

- uses the existing transforms to transform code
- optionally inline `__DEV__`, `process.env.NODE_ENV`, and `Platform.OS`
- optionally eliminate branches of conditionals with constant conditions
- extracts dependencies
- optionally minifies

This will land as part of a multi-commit stack, not in isolation

Reviewed By: martinbigio

Differential Revision: D2976677

fb-gh-sync-id: 38e317f90b6948b28ef2e3fe8b66fc0b9c75aa38
shipit-source-id: 38e317f90b6948b28ef2e3fe8b66fc0b9c75aa38

react-packager/src/JSTransformer/worker/__tests__/constant-folding-test.js

@@ -0,0 +1,112 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * 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.
+ */
+'use strict';
+
+jest.autoMockOff();
+const babel = require('babel-core');
+const constantFolding = require('../constant-folding');
+
+function parse(code) {
+  return babel.transform(code, {code: false, babelrc: false, compact: true});
+}
+
+describe('constant expressions', () => {
+  it('can optimize conditional expressions with constant conditions', () => {
+    const code = `
+      a(
+        'production'=="production",
+        'production'!=='development',
+        false && 1 || 0 || 2,
+        true || 3,
+        'android'==='ios' ? null : {},
+        'android'==='android' ? {a:1} : {a:0},
+        'foo'==='bar' ? b : c,
+        f() ? g() : h()
+      );`;
+    expect(constantFolding('arbitrary.js', parse(code)).code)
+      .toEqual(`a(true,true,2,true,{},{a:1},c,f()?g():h());`);
+  });
+
+  it('can optimize ternary expressions with constant conditions', () => {
+    const code =
+      `var a = true ? 1 : 2;
+       var b = 'android' == 'android'
+         ? ('production' != 'production' ? 'a' : 'A')
+         : 'i';`;
+    expect(constantFolding('arbitrary.js', parse(code)).code)
+      .toEqual(`var a=1;var b='A';`);
+  });
+
+  it('can optimize logical operator expressions with constant conditions', () => {
+    const code = `
+      var a = true || 1;
+      var b = 'android' == 'android' &&
+        'production' != 'production' || null || "A";`;
+    expect(constantFolding('arbitrary.js', parse(code)).code)
+      .toEqual(`var a=true;var b="A";`);
+  });
+
+  it('can optimize logical operators with partly constant operands', () => {
+    const code = `
+      var a = "truthy" || z();
+      var b = "truthy" && z();
+      var c = null && z();
+      var d = null || z();
+      var e = !1 && z();
+    `;
+    expect(constantFolding('arbitrary.js', parse(code)).code)
+      .toEqual(`var a="truthy";var b=z();var c=null;var d=z();var e=false;`);
+  });
+
+  it('can remode an if statement with a falsy constant test', () => {
+    const code = `
+      if ('production' === 'development' || false) {
+        var a = 1;
+      }
+    `;
+    expect(constantFolding('arbitrary.js', parse(code)).code)
+      .toEqual(``);
+  });
+
+  it('can optimize if-else-branches with constant conditions', () => {
+    const code = `
+      if ('production' == 'development') {
+        var a = 1;
+        var b = a + 2;
+      } else if ('development' == 'development') {
+        var a = 3;
+        var b = a + 4;
+      } else {
+        var a = 'b';
+      }
+    `;
+    expect(constantFolding('arbitrary.js', parse(code)).code)
+      .toEqual(`{var a=3;var b=a+4;}`);
+  });
+
+  it('can optimize nested if-else constructs', () => {
+    const code = `
+      if ('ios' === "android") {
+        if (true) {
+          require('a');
+        } else {
+          require('b');
+        }
+      } else if ('android' === 'android') {
+        if (true) {
+          require('c');
+        } else {
+          require('d');
+        }
+      }
+    `;
+    expect(constantFolding('arbitrary.js', parse(code)).code)
+      .toEqual(`{{require('c');}}`);
+  });
+});

react-packager/src/JSTransformer/worker/__tests__/extract-dependencies-test.js

@@ -0,0 +1,96 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * 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.
+ */
+'use strict';
+
+jest.autoMockOff();
+
+const extractDependencies = require('../extract-dependencies');
+
+describe('Dependency extraction:', () => {
+  it('can extract calls to require', () => {
+    const code = `require('foo/bar');
+      var React = require("React");
+      var A = React.createClass({
+        render: function() {
+          return require (  "Component" );
+        }
+      });
+      require
+      ('more');`
+    const {dependencies, dependencyOffsets} = extractDependencies(code);
+    expect(dependencies)
+      .toEqual(['foo/bar', 'React', 'Component', 'more']);
+    expect(dependencyOffsets).toEqual([8, 46, 147, 203]);
+  });
+
+  it('does not extract require method calls', () => {
+    const code = `
+      require('a');
+      foo.require('b');
+      bar.
+      require ( 'c').require('d')require('e')`;
+
+    const {dependencies, dependencyOffsets} = extractDependencies(code);
+    expect(dependencies).toEqual(['a', 'e']);
+    expect(dependencyOffsets).toEqual([15, 97]);
+  });
+
+  it('does not extract require calls from strings', () => {
+    const code = `require('foo');
+      var React = '\\'require("React")';
+      var a = ' // require("yadda")';
+      var a = ' /* require("yadda") */';
+      var A = React.createClass({
+        render: function() {
+          return require (  "Component" );
+        }
+      });
+      " \\" require('more')";`
+
+    const {dependencies, dependencyOffsets} = extractDependencies(code);
+    expect(dependencies).toEqual(['foo', 'Component']);
+    expect(dependencyOffsets).toEqual([8, 226]);
+  });
+
+  it('does not extract require calls in comments', () => {
+    const code = `require('foo')//require("not/this")
+      /* A comment here with a require('call') that should not be extracted */require('bar')
+    // ending comment without newline require("baz")`;
+
+    const {dependencies, dependencyOffsets} = extractDependencies(code);
+    expect(dependencies).toEqual(['foo', 'bar']);
+    expect(dependencyOffsets).toEqual([8, 122]);
+  });
+
+  it('deduplicates dependencies', () => {
+    const code = `require('foo');require( "foo" );
+      require("foo");`;
+
+    const {dependencies, dependencyOffsets} = extractDependencies(code);
+    expect(dependencies).toEqual(['foo']);
+    expect(dependencyOffsets).toEqual([8, 24, 47]);
+  });
+
+  it('does not extract calls to function with names that start with "require"', () => {
+    const code = `arbitraryrequire('foo');`;
+
+    const {dependencies, dependencyOffsets} = extractDependencies(code);
+    expect(dependencies).toEqual([]);
+    expect(dependencyOffsets).toEqual([]);
+  });
+
+  it('does not get confused by previous states', () => {
+    // yes, this was a bug
+    const code = `require("a");/* a comment */ var a = /[a]/.test('a');`
+
+    const {dependencies, dependencyOffsets} = extractDependencies(code);
+    expect(dependencies).toEqual(['a']);
+    expect(dependencyOffsets).toEqual([8]);
+  });
+});

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

@@ -0,0 +1,133 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * 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.
+ */
+'use strict';
+
+jest.autoMockOff();
+const inline = require('../inline');
+const {transform, transformFromAst} = require('babel-core');
+
+const babelOptions = {
+  babelrc: false,
+  compact: true,
+};
+
+function toString(ast) {
+  return normalize(transformFromAst(ast, babelOptions).code);
+}
+
+function normalize(code) {
+  return transform(code, babelOptions).code;
+}
+
+function toAst(code) {
+  return transform(code, {...babelOptions, code: false}).ast;
+}
+
+describe('inline constants', () => {
+  it('replaces __DEV__ in the code', () => {
+    const code = `function a() {
+      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')));
+  });
+
+  it('replaces Platform.OS in the code if Platform is a global', () => {
+    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"')));
+  });
+
+  it('replaces Platform.OS in the code if Platform is a top level import', () => {
+    const code = `
+      var Platform = require('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"')));
+  });
+
+  it('replaces require("Platform").OS in the code', () => {
+    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"')));
+  });
+
+  it('replaces React.Platform.OS in the code if React is a global', () => {
+    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 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"')));
+  });
+
+  it('replaces require("React").Platform.OS in the code', () => {
+    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 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"')));
+  });
+
+  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: true});
+    expect(toString(ast)).toEqual(
+      normalize(code.replace(/process\.env\.NODE_ENV/, '"development"')));
+  });
+
+  it('accepts an AST as input', function() {
+    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'))
+  });
+});
+