Merge pull request expo#503 from connectdotz/yarn-lookup-fix

fixed using wrong package manager in yarn workspace projects

Author: fson

package.json

@@ -1,9 +1,17 @@
 {
   "private": true,
   "scripts": {
-    "format": "prettier --single-quote --trailing-comma=es5 --print-width=100 --write '{create-react-native-app,react-native-scripts}/{src,template}/**/*.js'"
+    "format": "prettier --single-quote --trailing-comma=es5 --print-width=100 --write '{create-react-native-app,react-native-scripts}/{src,template}/**/*.js'",
+    "test": "jest"
   },
   "devDependencies": {
+    "jest": "^21.2.1",
     "prettier": "^0.21.0"
+  },
+  "jest": {
+    "testPathIgnorePatterns": [
+      "node_modules",
+      "template"
+    ]
   }
 }

react-native-scripts/__mocks__/fs.js

@@ -0,0 +1,43 @@
+// based on jest official doc: https://facebook.github.io/jest/docs/en/manual-mocks.html
+// __mocks__/fs.js
+'use strict';
+
+const path = require('path');
+
+const fs = jest.genMockFromModule('fs');
+
+// This is a custom function that our tests can use during setup to specify
+// what the files on the "mock" filesystem should look like when any of the
+// `fs` APIs are used.
+let mockFiles = Object.create(null);
+function __setMockFiles(newMockFiles) {
+  mockFiles = Object.create(null);
+  for (const file in newMockFiles) {
+    const dir = path.dirname(file);
+    if (!mockFiles[dir]) {
+      mockFiles[dir] = [];
+    }
+    mockFiles[dir].push(path.basename(file));
+  }
+}
+
+// A custom version of `readdirSync` that reads from the special mocked out
+// file list set via __setMockFiles
+function readdirSync(directoryPath) {
+  return mockFiles[directoryPath] || [];
+}
+
+function accessSync(directoryPath) {
+  const dir = path.dirname(directoryPath);
+  const children = mockFiles[dir];
+
+  if (!children || children.indexOf(path.basename(directoryPath)) < 0) {
+    throw new TypeError(`no such file/dir: ${directoryPath}`);
+  }
+}
+
+fs.__setMockFiles = __setMockFiles;
+fs.readdirSync = readdirSync;
+fs.accessSync = accessSync;
+
+module.exports = fs;

react-native-scripts/src/scripts/eject.js

@@ -8,6 +8,7 @@ import path from 'path';
 import rimraf from 'rimraf';
 import spawn from 'cross-spawn';
 import log from '../util/log';
+import { hasYarn } from '../util/pm';
 
 import { detach } from '../util/expo';
 
@@ -78,7 +79,7 @@ Ejecting is permanent! Please be careful with your selection.
     const { ejectMethod } = await inquirer.prompt(questions);
 
     if (ejectMethod === 'raw') {
-      const useYarn = await fse.exists(path.resolve('yarn.lock'));
+      const useYarn = hasYarn(process.cwd());
       const npmOrYarn = useYarn ? 'yarn' : 'npm';
       const appJson = JSON.parse(await fse.readFile(path.resolve('app.json')));
       const pkgJson = JSON.parse(await fse.readFile(path.resolve('package.json')));

react-native-scripts/src/scripts/init.js

@@ -7,6 +7,7 @@ import pathExists from 'path-exists';
 import spawn from 'cross-spawn';
 import log from '../util/log';
 import install from '../util/install';
+import { hasYarn } from '../util/pm';
 
 // UPDATE DEPENDENCY VERSIONS HERE
 const DEFAULT_DEPENDENCIES = {
@@ -24,7 +25,7 @@ const DEFAULT_DEV_DEPENDENCIES = {
 module.exports = async (appPath: string, appName: string, verbose: boolean, cwd: string = '') => {
   const ownPackageName: string = require('../../package.json').name;
   const ownPath: string = path.join(appPath, 'node_modules', ownPackageName);
-  const useYarn: boolean = await pathExists(path.join(appPath, 'yarn.lock'));
+  const useYarn: boolean = hasYarn(appPath);
   const npmOrYarn = useYarn ? 'yarn' : 'npm';
 
   // FIXME(perry) remove when npm 5 is supported

react-native-scripts/src/scripts/ios.js

@@ -8,14 +8,15 @@ import path from 'path';
 import pathExists from 'path-exists';
 import qr from 'qrcode-terminal';
 import log from '../util/log';
+import { hasYarn } from '../util/pm';
 
 import packager from '../util/packager';
 
 Config.validation.reactNativeVersionWarnings = false;
 Config.developerTool = 'crna';
 Config.offline = true;
 
-const command: string = pathExists.sync(path.join(process.cwd(), 'yarn.lock')) ? 'yarnpkg' : 'npm';
+const command: string = hasYarn(process.cwd()) ? 'yarnpkg' : 'npm';
 
 if (!Simulator.isPlatformSupported()) {
   log(

react-native-scripts/src/util/__tests__/pm.test.js

@@ -0,0 +1,35 @@
+'use strict';
+
+jest.mock('fs');
+
+import { hasYarn } from '../pm';
+
+describe('hasYarn', () => {
+  const MOCK_FILE_INFO = {
+    '/a/b/yarn.lock': 'fake yarn.lock',
+  };
+
+  beforeEach(() => {
+    // Set up some mocked out file info before each test
+    require('fs').__setMockFiles(MOCK_FILE_INFO);
+  });
+  test('undefined path will throw exception', () => {
+    expect(() => hasYarn(undefined, false)).toThrow();
+  });
+  test('empty path is ok', () => {
+    expect(hasYarn('', false)).toEqual(false);
+  });
+  test('can find yarn in the given path', () => {
+    expect(hasYarn('/a/b', false)).toEqual(true);
+  });
+  test('can find yarn in the parent path', () => {
+    expect(hasYarn('/a/b/c/d/e', false)).toEqual(true);
+  });
+  test('can NOT find yarn in the children path', () => {
+    expect(hasYarn('/a', false)).toEqual(false);
+  });
+  test('can use cached value 2nd time around', () => {
+    expect(hasYarn('/a/b/c/d/e', false)).toEqual(true);
+    expect(hasYarn(undefined, true)).toEqual(true);
+  });
+});

react-native-scripts/src/util/install.js

@@ -4,6 +4,7 @@ import spawn from 'cross-spawn';
 import pathExists from 'path-exists';
 import path from 'path';
 import log from '../util/log';
+import { hasYarn } from './pm';
 
 type InstallResult = {
   code: number,
@@ -17,7 +18,7 @@ export default (async function install(
   packageVersion?: string,
   options?: any = {}
 ): Promise<InstallResult> {
-  const useYarn: boolean = await pathExists(path.join(appPath, 'yarn.lock'));
+  const useYarn: boolean = hasYarn(appPath);
 
   let command = '';
   let args = [];

react-native-scripts/src/util/pm.js

@@ -0,0 +1,42 @@
+// @flow
+
+'use strict';
+
+import path from 'path';
+import fs from 'fs';
+
+/**
+ * check if the current path uses yarn, i.e. looking for yarn.lock in
+ * the current path and up
+ *  
+ * @param {*} startingPath a path where we will look for yarn.lock file. 
+ * Will traverse up the filesystem until we either find the file or reach the root
+ * 
+ * @param {boolean} useCached if true and we have a cached hasYarn result, it will be returned, otherwise go through the
+ * normal lookup logic described above. mainly for optimization purpose, default is true.
+ */
+let _hasYarn: ?boolean;
+export function hasYarn(startingPath: string, useCached: boolean = true): boolean {
+  if (_hasYarn != null && useCached) {
+    return _hasYarn;
+  }
+
+  _hasYarn = false;
+  let p = path.normalize(startingPath);
+  while (p.length > 0) {
+    const yarnLock = path.resolve(p, 'yarn.lock');
+    try {
+      const file = path.join(p, 'yarn.lock');
+      fs.accessSync(file);
+      _hasYarn = true;
+      break;
+    } catch (e) {
+      const parsed = path.parse(p);
+      if (parsed.root === parsed.dir) {
+        break;
+      }
+      p = parsed.dir;
+    }
+  }
+  return _hasYarn;
+}

react-native-scripts/taskfile.js

@@ -11,7 +11,7 @@ export default async function (fly) {
 }
 
 export async function babel(fly, opts) {
-  await fly.source(opts.src || paths.source).babel().target(paths.build);
+  await fly.source(opts.src || paths.source, {ignore: '**/__tests__/**'}).babel().target(paths.build);
 }
 
 export async function clean(fly) {