adds modifyBabelConfig

config/__tests__/babel.test.js

@@ -8,16 +8,36 @@ const stubBabelrc = {
     },
   },
 };
+jest.mock('../../cli/logger');
 jest.setMock('fs', {
   readFileSync: () => JSON.stringify(stubBabelrc),
 });
 jest.setMock('path', {
   resolve: a => a,
 });
 
+const modifyBabelConfig = jest.fn(c => c);
+const mockKytConfig = jest.fn(() => ({ modifyBabelConfig }));
+jest.setMock('../../utils/kytConfig', mockKytConfig);
+
+const logger = require('../../cli/logger');
+
 const babel = require('../babel');
 
 describe('babel', () => {
+  beforeEach(() => {
+    modifyBabelConfig.mockClear();
+    mockKytConfig.mockClear();
+    global.process.exit = jest.fn();
+    Object.keys(logger).forEach(k => logger[k].mockClear());
+  });
+
+  it('does not call process.exit or logger.error on a successful run', () => {
+    babel();
+    expect(logger.error).not.toBeCalled();
+    expect(global.process.exit).not.toBeCalled();
+  });
+
   it('sets flags', () => {
     const babelrc = babel();
     expect(babelrc.babelrc).toBe(false);
@@ -35,4 +55,40 @@ describe('babel', () => {
     expect(babelrc.env.development.plugins).toEqual([thisResolved]);
     expect(babelrc.env.development.presets).toEqual([[thisResolved]]);
   });
+
+  it('calls kytConfig\'s modifyBabelConfig', () => {
+    const opts = {};
+    babel(opts);
+    const kytConfig = require('../../utils/kytConfig');
+    const config = kytConfig();
+    expect(config.modifyBabelConfig).toBeCalled();
+    expect(config.modifyBabelConfig.mock.calls[0][0]).toEqual(Object.assign({}, stubBabelrc, {
+      babelrc: false,
+      cacheDirectory: false,
+      plugins: [],
+      presets: [],
+    }));
+    expect(config.modifyBabelConfig.mock.calls[0][1]).toBe(opts);
+  });
+
+  it('logs an error and exits the process if modifyBabelConfig throws', () => {
+    const err = new Error('oh no');
+    modifyBabelConfig.mockImplementationOnce(() => { throw err; });
+    babel();
+    expect(logger.error).toBeCalledWith('Error in your kyt.config.js modifyBabelConfig():', err);
+    expect(global.process.exit).toBeCalledWith(1);
+  });
+
+  it('does not log out merged config if config.debug is falsy', () => {
+    babel();
+    expect(logger.debug).not.toBeCalled();
+  });
+
+  it('logs out the merged config if config.debug is truthy', () => {
+    mockKytConfig.mockImplementationOnce(() => ({ debug: true, modifyBabelConfig }));
+    babel();
+    expect(logger.debug).toBeCalled();
+    expect(typeof logger.debug.mock.calls[0][0]).toBe('string');
+    expect(typeof logger.debug.mock.calls[0][1]).toBe('object');
+  });
 });

config/babel.js

@@ -1,5 +1,7 @@
 const path = require('path');
 const fs = require('fs');
+const getKytConfig = require('../utils/kytConfig');
+const logger = require('../cli/logger');
 
 // Uses require.resolve to add the full paths to all of the plugins
 // and presets, making sure that we handle the new array syntax.
@@ -16,6 +18,8 @@ const resolvePluginsPresets = (babelGroup) => {
 };
 
 module.exports = (options) => {
+  const config = getKytConfig();
+
   // Create the babelrc query for the babel loader.
   const babelrc = JSON.parse(fs.readFileSync(path.resolve(__dirname, '../.babelrc'), 'utf8'));
   babelrc.babelrc = false;
@@ -26,5 +30,16 @@ module.exports = (options) => {
   }
   Object.keys(babelrc.env || {}).forEach(env => resolvePluginsPresets(babelrc.env[env]));
 
-  return babelrc;
+  // modify via userland kytConfig's `modifyBabelConfig`
+  try {
+    const mergedBabelrc = config.modifyBabelConfig(babelrc, options);
+    if (config.debug) {
+      logger.debug('Merged babel configuration:', mergedBabelrc);
+    }
+    return mergedBabelrc;
+  } catch (error) {
+    logger.error('Error in your kyt.config.js modifyBabelConfig():', error);
+    // return to satisfy eslint `consistent-return` rule
+    return process.exit(1);
+  }
 };

utils/__tests__/kytConfig.test.js

@@ -30,6 +30,7 @@ describe('kytConfig', () => {
     expect(logger.info).toBeCalled();
     expect(typeof config.modifyWebpackConfig).toBe('function');
     expect(typeof config.modifyJestConfig).toBe('function');
+    expect(typeof config.modifyBabelConfig).toBe('function');
     expect(() => {
       config.productionPublicPath = 'frozen!';
     }).toThrow();

utils/jest/__tests__/preprocessor.test.js

@@ -0,0 +1,23 @@
+const fakeTransformer = {};
+
+jest.setMock('babel-jest', {
+  createTransformer: jest.fn(() => fakeTransformer),
+});
+const babelJest = require('babel-jest');
+
+const fakeBabelResult = {};
+
+jest.setMock('../../../config/babel', jest.fn(() => fakeBabelResult));
+const babel = require('../../../config/babel');
+
+describe('preprocessor', () => {
+  it('calls the babel utility and babel-jest\'s createTransformer', () => {
+    const preprocessor = require('../preprocessor'); // eslint-disable-line global-require
+    expect(preprocessor).toBe(fakeTransformer);
+    expect(babel.mock.calls[0][0]).toEqual({
+      type: 'test',
+      environment: 'test',
+    });
+    expect(babelJest.createTransformer).toBeCalledWith(fakeBabelResult);
+  });
+});

utils/jest/preprocessor.js

@@ -1,17 +1,10 @@
-const mergeAll = require('ramda').mergeAll;
-const babel = require('../../config/babel')();
 const babelJest = require('babel-jest');
-const buildConfigs = require('../buildConfigs');
-const config = require('../kytConfig')();
 
-const { clientConfig } = buildConfigs(config);
+const options = {
+  type: 'test',
+  environment: 'test',
+};
 
-// Merge userland babel config with our babel config
-// This should go away after https://github.com/NYTimes/kyt/issues/134
-const clientBabelConfig = clientConfig.module.loaders
-  .find(loader => loader.loader === 'babel-loader')
-  .query;
-
-const babelConfigForJest = mergeAll([{}, babel, clientBabelConfig]);
+const babelConfigForJest = require('../../config/babel')(options);
 
 module.exports = babelJest.createTransformer(babelConfigForJest);

utils/kytConfig.js

@@ -40,7 +40,7 @@ module.exports = (optionalConfig) => {
   config = mergeAll([{}, baseConfig, config]);
 
   // Create default identity functions for modify functions
-  ['modifyWebpackConfig', 'modifyJestConfig'].forEach((m) => {
+  ['modifyWebpackConfig', 'modifyJestConfig', 'modifyBabelConfig'].forEach((m) => {
     if (typeof config[m] !== 'function') {
       config[m] = c => c;
     }