Remove baseTransformer

Reviewed By: jeanlauliac

Differential Revision: D4506124

fbshipit-source-id: 642f06dffe4ea710113e8e8426915bf1b40d4611

packages/metro-bundler/src/JSTransformer/worker/__tests__/worker-test.js

@@ -14,35 +14,46 @@ jest.mock('../extract-dependencies');
 jest.mock('../inline');
 jest.mock('../minify');
 
-const {any, objectContaining} = jasmine;
+const {objectContaining} = jasmine;
 
 describe('code transformation worker:', () => {
   let transformCode;
 
-  let extractDependencies, transform;
+  let extractDependencies, transformer;
   beforeEach(() => {
     jest.resetModules();
     ({transformCode} = require('..'));
     extractDependencies =
       require('../extract-dependencies').mockReturnValue({});
-    transform = jest.fn();
+    transformer = {
+      transform: jest.fn((src, filename, options) => ({
+        code: src,
+        map: {},
+      })),
+    };
   });
 
   it('calls the transform with file name, source code, and transform options', function() {
     const filename = 'arbitrary/file.js';
     const sourceCode = 'arbitrary(code)';
     const transformOptions = {arbitrary: 'options'};
-    transformCode(transform, filename, sourceCode, {transform: transformOptions});
-    expect(transform).toBeCalledWith(
-      {filename, sourceCode, options: transformOptions}, any(Function));
+    transformCode(transformer, filename, sourceCode, {transform: transformOptions}, () => {});
+    expect(transformer.transform).toBeCalledWith(
+      sourceCode,
+      filename,
+      transformOptions,
+    );
   });
 
   it('prefixes JSON files with an assignment to module.exports to make the code valid', function() {
     const filename = 'arbitrary/file.json';
     const sourceCode = '{"arbitrary":"property"}';
-    transformCode(transform, filename, sourceCode, {});
-    expect(transform).toBeCalledWith(
-      {filename, sourceCode: `module.exports=${sourceCode}`}, any(Function));
+    transformCode(transformer, filename, sourceCode, {}, () => {});
+    expect(transformer.transform).toBeCalledWith(
+      `module.exports=${sourceCode}`,
+      filename,
+      undefined,
+    );
   });
 
   it('calls back with the result of the transform in the cache', done => {
@@ -50,10 +61,8 @@ describe('code transformation worker:', () => {
       code: 'some.other(code)',
       map: {}
     };
-    transform.mockImplementation((_, callback) =>
-      callback(null, result));
 
-    transformCode(transform, 'filename', 'code', {}, (error, data) => {
+    transformCode(transformer, 'filename', result.code, {}, (error, data) => {
       expect(error).toBeNull();
       expect(data.result).toEqual(objectContaining(result));
       done();
@@ -64,14 +73,11 @@ describe('code transformation worker:', () => {
     'removes the leading assignment to `module.exports` before passing ' +
     'on the result if the file is a JSON file, even if minified',
     done => {
-      const result = {
-        code: 'p.exports={a:1,b:2}',
-      };
-      transform.mockImplementation((_, callback) => callback(null, result));
+      const code = '{a:1,b:2}';
       const filePath = 'arbitrary/file.json';
-      transformCode(transform, filePath, 'b', {}, (error, data) => {
+      transformCode(transformer, filePath, code, {}, (error, data) => {
           expect(error).toBeNull();
-          expect(data.result.code).toEqual('{a:1,b:2}');
+          expect(data.result.code).toEqual(code);
           done();
         },
       );
@@ -83,9 +89,8 @@ describe('code transformation worker:', () => {
     const result = {
       code: `${shebang} \n arbitrary(code)`,
     };
-    transform.mockImplementation((_, callback) => callback(null, result));
     const filePath = 'arbitrary/file.js';
-    transformCode(transform, filePath, 'b', {}, (error, data) => {
+    transformCode(transformer, filePath, result.code, {}, (error, data) => {
       expect(error).toBeNull();
       const {code} = data.result;
       expect(code).not.toContain(shebang);
@@ -95,26 +100,22 @@ describe('code transformation worker:', () => {
   });
 
   it('calls back with any error yielded by the transform', done => {
-    const error = Error('arbitrary error');
-    transform.mockImplementation((_, callback) => callback(error));
-    transformCode(transform, 'filename', 'code', {}, e => {
-      expect(e).toBe(error);
+    const message = 'SyntaxError: this code is broken.';
+    transformer.transform.mockImplementation(() => {
+      throw new Error(message);
+    });
+
+    transformCode(transformer, 'filename', 'code', {}, error => {
+      expect(error.message).toBe(message);
       done();
     });
   });
 
-  describe('dependency extraction:', () => {
-    let code;
-
-    beforeEach(() => {
-      transform.mockImplementation(
-        (_, callback) => callback(null, {code}));
-    });
-
+  describe('dependency extraction', () => {
     it('passes the transformed code the `extractDependencies`', done => {
-      code = 'arbitrary(code)';
+      const code = 'arbitrary(code)';
 
-      transformCode(transform, 'filename', 'code', {}, (error) => {
+      transformCode(transformer, 'filename', code, {}, (error) => {
         expect(error).toBeNull();
         expect(extractDependencies).toBeCalledWith(code);
         done();
@@ -131,7 +132,7 @@ describe('code transformation worker:', () => {
         };
         extractDependencies.mockReturnValue(dependencyData);
 
-        transformCode(transform, 'filename', 'code', {}, (error, data) => {
+        transformCode(transformer, 'filename', 'code', {}, (error, data) => {
           expect(error).toBeNull();
           expect(data.result).toEqual(objectContaining(dependencyData));
           done();
@@ -141,7 +142,7 @@ describe('code transformation worker:', () => {
 
     it('does not extract requires if files are marked as "extern"', done => {
       const opts = {extern: true};
-      transformCode(transform, 'filename', 'code', opts, (error, data) => {
+      transformCode(transformer, 'filename', 'code', opts, (error, data) => {
           expect(error).toBeNull();
           const {dependencies, dependencyOffsets} = data.result;
           expect(extractDependencies).not.toBeCalled();
@@ -153,7 +154,7 @@ describe('code transformation worker:', () => {
 
     it('does not extract requires of JSON files', done => {
       const jsonStr = '{"arbitrary":"json"}';
-      transformCode(transform, 'arbitrary.json', jsonStr, {}, (error, data) => {
+      transformCode(transformer, 'arbitrary.json', jsonStr, {}, (error, data) => {
           expect(error).toBeNull();
           const {dependencies, dependencyOffsets} = data.result;
           expect(extractDependencies).not.toBeCalled();
@@ -187,13 +188,12 @@ describe('code transformation worker:', () => {
       extractDependencies.mockImplementation(
         code => code === foldedCode ? dependencyData : {});
 
-      transform.mockImplementation(
-        (_, callback) => callback(null, transformResult));
+      transformer.transform.mockImplementation((src, fileName, _) => transformResult);
     });
 
     it('passes the transform result to `inline` for constant inlining', done => {
       transformResult = {map: {version: 3}, code: 'arbitrary(code)'};
-      transformCode(transform, filename, 'code', options, () => {
+      transformCode(transformer, filename, 'code', options, () => {
         expect(inline).toBeCalledWith(filename, transformResult, options);
         done();
       });
@@ -202,21 +202,21 @@ describe('code transformation worker:', () => {
     it('passes the result obtained from `inline` on to `constant-folding`', done => {
       const inlineResult = {map: {version: 3, sources: []}, ast: {}};
       inline.mockReturnValue(inlineResult);
-      transformCode(transform, filename, 'code', options, () => {
+      transformCode(transformer, filename, 'code', options, () => {
         expect(constantFolding).toBeCalledWith(filename, inlineResult);
         done();
       });
     });
 
     it('Uses the code obtained from `constant-folding` to extract dependencies', done => {
-      transformCode(transform, filename, 'code', options, () => {
+      transformCode(transformer, filename, 'code', options, () => {
         expect(extractDependencies).toBeCalledWith(foldedCode);
         done();
       });
     });
 
     it('uses the dependencies obtained from the optimized result', done => {
-      transformCode(transform, filename, 'code', options, (_, data) => {
+      transformCode(transformer, filename, 'code', options, (_, data) => {
         const result = data.result;
         expect(result.dependencies).toEqual(dependencyData.dependencies);
         done();
@@ -224,7 +224,7 @@ describe('code transformation worker:', () => {
     });
 
     it('uses data produced by `constant-folding` for the result', done => {
-      transformCode(transform, 'filename', 'code', options, (_, data) => {
+      transformCode(transformer, 'filename', 'code', options, (_, data) => {
         expect(data.result)
           .toEqual(objectContaining({code: foldedCode, map: foldedMap}));
         done();

packages/metro-bundler/src/JSTransformer/worker/worker.js

@@ -20,20 +20,6 @@ const minify = require('./minify');
 import type {LogEntry} from '../../Logger/Types';
 import type {Ast, SourceMap, TransformOptions as BabelTransformOptions} from 'babel-core';
 
-function makeTransformParams(filename, sourceCode, options, willMinify) {
-  invariant(
-    !willMinify || options.generateSourceMaps,
-    'Minifying source code requires the `generateSourceMaps` option to be `true`',
-  );
-
-
-  if (filename.endsWith('.json')) {
-    sourceCode = 'module.exports=' + sourceCode;
-  }
-
-  return {filename, sourceCode, options};
-}
-
 export type TransformedCode = {
   code: string,
   dependencies: Array<string>,
@@ -41,17 +27,13 @@ export type TransformedCode = {
   map?: ?SourceMap,
 };
 
-type Transform = (
-  params: {
+type Transformer = {
+  transform: (
     filename: string,
     sourceCode: string,
     options: ?{},
-  },
-  callback: (
-    error?: Error,
-    tranformed?: {ast: ?Ast, code: string, map: ?SourceMap},
-  ) => mixed,
-) => void;
+  ) => {ast: ?Ast, code: string, map: ?SourceMap}
+};
 
 export type TransformOptions = {
   generateSourceMaps: boolean,
@@ -80,19 +62,21 @@ type Callback = (
 ) => mixed;
 
 function transformCode(
-  transform: Transform,
+  transformer: Transformer,
   filename: string,
   sourceCode: string,
   options: Options,
   callback: Callback,
 ) {
-  const params = makeTransformParams(
-    filename,
-    sourceCode,
-    options.transform,
-    options.minify,
+  invariant(
+    !options.minify || options.transform.generateSourceMaps,
+    'Minifying source code requires the `generateSourceMaps` option to be `true`',
   );
+
   const isJson = filename.endsWith('.json');
+  if (isJson) {
+    sourceCode = 'module.exports=' + sourceCode;
+  }
 
   const transformFileStartLogEntry = {
     action_name: 'Transforming file',
@@ -102,8 +86,10 @@ function transformCode(
     start_timestamp: process.hrtime(),
   };
 
-  transform(params, (error, transformed) => {
-    if (error) {
+  let transformed;
+  try {
+    transformed = transformer.transform(sourceCode, filename, options.transform);
+  } catch (error) {
     callback(error);
     return;
   }
@@ -143,12 +129,11 @@ function transformCode(
     log_entry_label: 'Transforming file',
   };
 
-    return callback(null, {
+  callback(null, {
     result: {...depsResult, code, map},
     transformFileStartLogEntry,
     transformFileEndLogEntry,
   });
-  });
 }
 
 exports.transformAndExtractDependencies = (

packages/metro-bundler/src/ModuleGraph/types.flow.js

@@ -11,6 +11,7 @@
 'use strict';
 
 import type {SourceMap} from './output/source-map';
+import type {Ast} from 'babel-core';
 import type {Console} from 'console';
 
 export type Callback<A = void, B = void>
@@ -99,18 +100,19 @@ type ResolveOptions = {
   log?: Console,
 };
 
-export type TransformFn = (
-  data: {|
-    filename: string,
-    options?: Object,
-    plugins?: Array<string | Object | [string | Object, any]>,
-    sourceCode: string,
-  |},
-  callback: Callback<TransformFnResult>
-) => void;
+export type TransformerResult = {
+  ast: ?Ast,
+  code: string,
+  map: ?SourceMap,
+};
 
-export type TransformFnResult = {
-  ast: Object,
+export type Transformer = {
+  transform: (
+    sourceCode: string,
+    filename: string,
+    options: ?{},
+    plugins?: Array<string | Object | [string | Object, any]>,
+  ) => {ast: ?Ast, code: string, map: ?SourceMap}
 };
 
 export type TransformResult = {|

packages/metro-bundler/src/ModuleGraph/worker/__tests__/optimize-module-test.js

@@ -12,7 +12,7 @@ jest.disableAutomock();
 
 const optimizeModule = require('../optimize-module');
 const transformModule = require('../transform-module');
-const transform = require('../../../../transformer.js');
+const transformer = require('../../../../transformer.js');
 const {SourceMapConsumer} = require('source-map');
 
 const {objectContaining} = jasmine;
@@ -32,7 +32,7 @@ describe('optimizing JS modules', () => {
 
   let transformResult;
   beforeAll(done => {
-    transformModule(originalCode, {filename, transform}, (error, result) => {
+    transformModule(originalCode, {filename, transformer}, (error, result) => {
       if (error) {
         throw error;
       }

packages/metro-bundler/src/ModuleGraph/worker/__tests__/transform-module-test.js

@@ -24,18 +24,20 @@ const {any, objectContaining} = jasmine;
 describe('transforming JS modules:', () => {
   const filename = 'arbitrary';
 
-  let transform;
+  let transformer;
 
   beforeEach(() => {
-    transform = fn();
-    transform.stub.yields(null, transformResult());
+    transformer = {
+      transform: fn(),
+    };
+    transformer.transform.stub.returns(transformResult());
   });
 
   const {bodyAst, sourceCode, transformedCode} = createTestData();
 
   const options = variants => ({
     filename,
-    transform,
+    transformer,
     variants,
   });
 
@@ -80,17 +82,17 @@ describe('transforming JS modules:', () => {
     const variants = {dev: {dev: true}, prod: {dev: false}};
 
     transformModule(sourceCode, options(variants), () => {
-      expect(transform)
-        .toBeCalledWith({filename, sourceCode, options: variants.dev}, any(Function));
-      expect(transform)
-        .toBeCalledWith({filename, sourceCode, options: variants.prod}, any(Function));
+      expect(transformer.transform)
+        .toBeCalledWith(sourceCode, filename, variants.dev);
+      expect(transformer.transform)
+        .toBeCalledWith(sourceCode, filename, variants.prod);
       done();
     });
   });
 
   it('calls back with any error yielded by the transform function', done => {
     const error = new Error();
-    transform.stub.yields(error);
+    transformer.transform.stub.throws(error);
 
     transformModule(sourceCode, options(), e => {
       expect(e).toBe(error);
@@ -138,7 +140,7 @@ describe('transforming JS modules:', () => {
     const dep1 = 'foo', dep2 = 'bar';
     const code = `require('${dep1}'),require('${dep2}')`;
     const {body} = parse(code).program;
-    transform.stub.yields(null, transformResult(body));
+    transformer.transform.stub.returns(transformResult(body));
 
     transformModule(code, options(), (error, result) => {
       expect(result.transformed.default)
@@ -149,11 +151,11 @@ describe('transforming JS modules:', () => {
 
   it('transforms for all variants', done => {
     const variants = {dev: {dev: true}, prod: {dev: false}};
-    transform.stub
+    transformer.transform.stub
       .withArgs(filename, sourceCode, variants.dev)
-        .yields(null, transformResult(bodyAst))
+        .returns(transformResult(bodyAst))
       .withArgs(filename, sourceCode, variants.prod)
-        .yields(null, transformResult([]));
+        .returns(transformResult([]));
 
     transformModule(sourceCode, options(variants), (error, result) => {
       const {dev, prod} = result.transformed;

packages/metro-bundler/src/ModuleGraph/worker/transform-module.js

@@ -21,8 +21,8 @@ const {basename} = require('path');
 import type {
   Callback,
   TransformedFile,
-  TransformFn,
-  TransformFnResult,
+  Transformer,
+  TransformerResult,
   TransformResult,
   TransformVariants,
 } from '../types.flow';
@@ -30,7 +30,7 @@ import type {
 export type TransformOptions = {|
   filename: string,
   polyfill?: boolean,
-  transform: TransformFn,
+  transformer: Transformer,
   variants?: TransformVariants,
 |};
 
@@ -47,17 +47,23 @@ function transformModule(
     return transformJSON(code, options, callback);
   }
 
-  const {filename, transform, variants = defaultVariants} = options;
+  const {filename, transformer, variants = defaultVariants} = options;
   const tasks = {};
   Object.keys(variants).forEach(name => {
-    tasks[name] = cb => transform({
+    tasks[name] = cb => {
+      try {
+        cb(null, transformer.transform(
+          code,
           filename,
-      sourceCode: code,
-      options: variants[name],
-    }, cb);
+          variants[name],
+        ));
+      } catch (error) {
+        cb(error, null);
+      }
+    };
   });
 
-  series(tasks, (error, results: {[key: string]: TransformFnResult}) => {
+  series(tasks, (error, results: {[key: string]: TransformerResult}) => {
     if (error) {
       callback(error);
       return;

packages/metro-bundler/transformer.js

@@ -126,17 +126,4 @@ function transform(src, filename, options) {
   }
 }
 
-module.exports = function(data, callback) {
-  let result;
-  try {
-    result = transform(data.sourceCode, data.filename, data.options);
-  } catch (e) {
-    callback(e);
-    return;
-  }
-
-  callback(null, result);
-};
-
-// export for use in jest
 module.exports.transform = transform;