Add ESLint (#52)

* Fix skipped test for add file to project

* Add ESLint config and fix all the errors

* Use proper lint command

* Function is required here

* This file is unused

* Remove extraneous files and move utils to correct folders

* Add strict mode to global-cli again and use preset for other places

* Revert changes to debugger-ui for browser compatibility

* Revert changes in global-cli, package should run on older Node too

.circleci/config.yml

@@ -31,7 +31,7 @@ jobs:
       - attach_workspace:
           at: ~/react-native-cli
       - run: |
-          # yarn lint – disable temporarily until ESLint is added to the project
+          yarn lint
           yarn flow-check
   tests:
     <<: *defaults

.eslintignore

@@ -0,0 +1,4 @@
+**/node_modules/**
+**/debugger-ui/**
+**/templates/**
+**/global-cli/**

package.json

@@ -5,6 +5,18 @@
   ],
   "scripts": {
     "test": "cd packages/local-cli && yarn jest; cd -",
+    "lint": "eslint packages",
     "flow-check": "cd packages/local-cli && yarn flow check; cd -"
+  },
+  "devDependencies": {
+    "@callstack/eslint-config": "^3.0.2",
+    "eslint": "^5.10.0"
+  },
+  "eslintConfig": {
+    "extends": "@callstack",
+    "rules": {
+      "global-require": 0,
+      "no-console": 0
+    }
   }
 }

packages/local-cli/__mocks__/beeper.js

@@ -7,9 +7,7 @@
  * @format
  */
 
-'use strict';
-
 // beeper@1.1.0 has a return statement outside of a function
 // and therefore doesn't parse. Let's mock it so that we can
 // run the tests.
-module.exports = function() {};
+module.exports = function beeper() {};

packages/local-cli/__mocks__/fs.js

@@ -3,37 +3,34 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @format
  */
 
-'use strict';
-
 const path = require('path');
 const MemoryFS = require('metro-memory-fs');
+
 let fs;
 
 function setMockFilesystem(object, platform) {
   reset(platform);
   const root = platform === 'win32' ? 'c:\\' : '/';
-  mockDir(root, {...object});
+  mockDir(root, { ...object });
   return root;
 }
 
 function mockDir(dirPath, desc) {
-  for (const entName in desc) {
+  for (const entName of Object.keys(desc)) {
     const ent = desc[entName];
     const entPath = path.join(dirPath, entName);
     if (typeof ent === 'string' || ent instanceof Buffer) {
       fs.writeFileSync(entPath, ent);
-      continue;
+      continue; // eslint-disable-line no-continue
     }
     if (typeof ent !== 'object') {
       throw new Error(require('util').format('invalid entity:', ent));
     }
     if (ent.SYMLINK != null) {
       fs.symlinkSync(ent.SYMLINK, entPath);
-      continue;
+      continue; // eslint-disable-line no-continue
     }
     fs.mkdirSync(entPath);
     mockDir(entPath, ent);
@@ -43,18 +40,18 @@ function mockDir(dirPath, desc) {
 function reset(platform) {
   if (path.mock == null) {
     throw new Error(
-      'to use this "fs" module mock, you must also mock the "path" module',
+      'to use this "fs" module mock, you must also mock the "path" module'
     );
   }
   path.mock.reset(platform);
   const cwd = () => (platform === 'win32' ? 'c:\\' : '/');
-  fs = new MemoryFS({platform, cwd});
+  fs = new MemoryFS({ platform, cwd });
   Object.assign(mockFs, fs);
 }
 
 const mockFs = {};
 mockFs.__setMockFilesystem = setMockFilesystem;
-mockFs.mock = {clear: reset};
+mockFs.mock = { clear: reset };
 
 reset('posix');
 

packages/local-cli/__mocks__/path.js

@@ -7,15 +7,13 @@
  * @format
  */
 
-'use strict';
-
 const mockPath = {};
 
 function reset(platform) {
   Object.assign(mockPath, jest.requireActual('path')[platform]);
 }
 
-mockPath.mock = {reset};
+mockPath.mock = { reset };
 
 reset('posix');
 

packages/local-cli/babel.config.js

@@ -1,4 +1,3 @@
-const path = require('path');
 const escapeRegExp = require('escape-string-regexp');
 
 module.exports = {
@@ -12,7 +11,6 @@ module.exports = {
     ],
     require.resolve('@babel/preset-flow'),
   ],
-  only: [
-    new RegExp('^' + escapeRegExp(__dirname))
-  ]
+  plugins: [require.resolve('@babel/plugin-transform-strict-mode')],
+  only: [new RegExp(`^${escapeRegExp(__dirname)}`)],
 };

packages/local-cli/bin.js

@@ -17,12 +17,12 @@ if (isInstalledGlobally()) {
   console.error(
     [
       chalk.red(
-        'Looks like you installed react-native globally, maybe you meant react-native-cli?',
+        'Looks like you installed react-native globally, maybe you meant react-native-cli?'
       ),
       chalk.red('To fix the issue, run:'),
       'npm uninstall -g react-native',
       'npm install -g react-native-cli',
-    ].join('\n'),
+    ].join('\n')
   );
   process.exit(1);
 } else {

packages/local-cli/bundle/__mocks__/sign.js

@@ -7,8 +7,6 @@
  * @format
  */
 
-'use strict';
-
 function sign(source) {
   return source;
 }

packages/local-cli/bundle/__tests__/filterPlatformAssetScales-test.js

@@ -8,8 +8,6 @@
  * @emails oncall+javascript_foundation
  */
 
-'use strict';
-
 jest.dontMock('../filterPlatformAssetScales').dontMock('../assetPathUtils');
 
 const filterPlatformAssetScales = require('../filterPlatformAssetScales');

packages/local-cli/bundle/__tests__/getAssetDestPathAndroid-test.js

@@ -8,13 +8,10 @@
  * @emails oncall+javascript_foundation
  */
 
-'use strict';
-
 jest.dontMock('../getAssetDestPathAndroid').dontMock('../assetPathUtils');
 
-const getAssetDestPathAndroid = require('../getAssetDestPathAndroid');
-
 const path = require('path');
+const getAssetDestPathAndroid = require('../getAssetDestPathAndroid');
 
 describe('getAssetDestPathAndroid', () => {
   it('should use the right destination folder', () => {
@@ -24,10 +21,10 @@ describe('getAssetDestPathAndroid', () => {
       httpServerLocation: '/assets/test',
     };
 
-    const expectDestPathForScaleToStartWith = (scale, path) => {
-      if (!getAssetDestPathAndroid(asset, scale).startsWith(path)) {
+    const expectDestPathForScaleToStartWith = (scale, location) => {
+      if (!getAssetDestPathAndroid(asset, scale).startsWith(location)) {
         throw new Error(
-          `asset for scale ${scale} should start with path '${path}'`,
+          `asset for scale ${scale} should start with path '${location}'`
         );
       }
     };
@@ -47,7 +44,7 @@ describe('getAssetDestPathAndroid', () => {
     };
 
     expect(getAssetDestPathAndroid(asset, 1)).toBe(
-      path.normalize('drawable-mdpi/app_test_icon.png'),
+      path.normalize('drawable-mdpi/app_test_icon.png')
     );
   });
 
@@ -69,7 +66,7 @@ describe('getAssetDestPathAndroid', () => {
     };
 
     expect(getAssetDestPathAndroid(asset, 1)).toBe(
-      path.normalize('raw/app_test_video.mp4'),
+      path.normalize('raw/app_test_video.mp4')
     );
   });
 });

packages/local-cli/bundle/__tests__/getAssetDestPathIOS-test.js

@@ -8,12 +8,10 @@
  * @emails oncall+javascript_foundation
  */
 
-'use strict';
-
 jest.dontMock('../getAssetDestPathIOS');
 
-const getAssetDestPathIOS = require('../getAssetDestPathIOS');
 const path = require('path');
+const getAssetDestPathIOS = require('../getAssetDestPathIOS');
 
 describe('getAssetDestPathIOS', () => {
   it('should build correct path', () => {
@@ -24,7 +22,7 @@ describe('getAssetDestPathIOS', () => {
     };
 
     expect(getAssetDestPathIOS(asset, 1)).toBe(
-      path.normalize('assets/test/icon.png'),
+      path.normalize('assets/test/icon.png')
     );
   });
 
@@ -36,10 +34,10 @@ describe('getAssetDestPathIOS', () => {
     };
 
     expect(getAssetDestPathIOS(asset, 2)).toBe(
-      path.normalize('assets/test/icon@2x.png'),
+      path.normalize('assets/test/icon@2x.png')
     );
     expect(getAssetDestPathIOS(asset, 3)).toBe(
-      path.normalize('assets/test/icon@3x.png'),
+      path.normalize('assets/test/icon@3x.png')
     );
   });
 });

packages/local-cli/bundle/assetPathUtils.js

@@ -8,8 +8,6 @@
  * @flow strict
  */
 
-'use strict';
-
 export type PackagerAsset = {
   +httpServerLocation: string,
   +name: string,
@@ -34,8 +32,9 @@ function getAndroidAssetSuffix(scale: number): string {
       return 'xxhdpi';
     case 4:
       return 'xxxhdpi';
+    default:
+      throw new Error('no such scale');
   }
-  throw new Error('no such scale');
 }
 
 // See https://developer.android.com/guide/topics/resources/drawable-resource.html
@@ -53,37 +52,38 @@ function getAndroidResourceFolderName(asset: PackagerAsset, scale: number) {
   if (!drawableFileTypes.has(asset.type)) {
     return 'raw';
   }
-  var suffix = getAndroidAssetSuffix(scale);
+  const suffix = getAndroidAssetSuffix(scale);
   if (!suffix) {
     throw new Error(
-      "Don't know which android drawable suffix to use for asset: " +
-        JSON.stringify(asset),
+      `Don't know which android drawable suffix to use for asset: ${JSON.stringify(
+        asset
+      )}`
     );
   }
-  const androidFolder = 'drawable-' + suffix;
+  const androidFolder = `drawable-${suffix}`;
   return androidFolder;
 }
 
 function getAndroidResourceIdentifier(asset: PackagerAsset) {
-  var folderPath = getBasePath(asset);
-  return (folderPath + '/' + asset.name)
+  const folderPath = getBasePath(asset);
+  return `${folderPath}/${asset.name}`
     .toLowerCase()
     .replace(/\//g, '_') // Encode folder structure in file name
     .replace(/([^a-z0-9_])/g, '') // Remove illegal chars
     .replace(/^assets_/, ''); // Remove "assets_" prefix
 }
 
 function getBasePath(asset: PackagerAsset) {
-  var basePath = asset.httpServerLocation;
+  let basePath = asset.httpServerLocation;
   if (basePath[0] === '/') {
     basePath = basePath.substr(1);
   }
   return basePath;
 }
 
 module.exports = {
-  getAndroidAssetSuffix: getAndroidAssetSuffix,
-  getAndroidResourceFolderName: getAndroidResourceFolderName,
-  getAndroidResourceIdentifier: getAndroidResourceIdentifier,
-  getBasePath: getBasePath,
+  getAndroidAssetSuffix,
+  getAndroidResourceFolderName,
+  getAndroidResourceIdentifier,
+  getBasePath,
 };

packages/local-cli/bundle/buildBundle.js

@@ -4,27 +4,29 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @format
+ * @flow
  */
 
-'use strict';
+import type { ContextT } from '../core/types.flow';
+import type { CommandLineArgs } from './bundleCommandLineArgs';
 
-const log = require('../util/log').out('bundle');
 const Server = require('metro/src/Server');
 
 const outputBundle = require('metro/src/shared/output/bundle');
 const path = require('path');
+const log = require('./log').out('bundle');
 const saveAssets = require('./saveAssets');
 
 const loadMetroConfig = require('../util/loadMetroConfig');
 
-import type { ContextT } from '../core/types.flow';
-import type { CommandLineArgs } from './bundleCommandLineArgs';
-
-async function buildBundle(args: CommandLineArgs, ctx: ContextT, output = outputBundle) {
+async function buildBundle(
+  args: CommandLineArgs,
+  ctx: ContextT,
+  output = outputBundle
+) {
   const config = await loadMetroConfig(ctx.root, {
     resetCache: args.resetCache,
-    config: args.config
+    config: args.config,
   });
 
   // This is used by a bazillion of npm modules we don't control so we don't

packages/local-cli/bundle/bundle.js

@@ -7,11 +7,8 @@
  * @format
  */
 
-'use strict';
-
 const buildBundle = require('./buildBundle');
 const bundleCommandLineArgs = require('./bundleCommandLineArgs');
-const outputBundle = require('metro/src/shared/output/bundle');
 
 /**
  * Builds the bundle starting to look for dependencies at the given entry path.