Merge pull request #13 from share/linter

👷 Add linting

Author: alecgibson

.eslintrc.js

@@ -0,0 +1,50 @@
+// The ESLint ecmaVersion argument is inconsistently used. Some rules will ignore it entirely, so if the rule has
+// been set, it will still error even if it's not applicable to that version number. Since Google sets these
+// rules, we have to turn them off ourselves.
+var DISABLED_ES6_OPTIONS = {
+  'no-var': 'off',
+  'prefer-rest-params': 'off'
+};
+
+var SHAREDB_RULES = {
+  // Comma dangle is not supported in ES3
+  'comma-dangle': ['error', 'never'],
+  // We control our own objects and prototypes, so no need for this check
+  'guard-for-in': 'off',
+  // Google prescribes different indents for different cases. Let's just use 2 spaces everywhere. Note that we have
+  // to override ESLint's default of 0 indents for this.
+  indent: ['error', 2, {
+    SwitchCase: 1
+  }],
+  // Less aggressive line length than Google, which is especially useful when we have a lot of callbacks in our code
+  'max-len': ['error',
+    {
+      code: 120,
+      tabWidth: 2,
+      ignoreUrls: true
+    }
+  ],
+  // Google overrides the default ESLint behaviour here, which is slightly better for catching erroneously unused
+  // variables
+  'no-unused-vars': ['error', {vars: 'all', args: 'after-used'}],
+  // It's more readable to ensure we only have one statement per line
+  'max-statements-per-line': ['error', {max: 1}],
+  // ES3 doesn't support spread
+  'prefer-spread': 'off',
+  // as-needed quote props are easier to write
+  'quote-props': ['error', 'as-needed'],
+  'require-jsdoc': 'off',
+  'valid-jsdoc': 'off'
+};
+
+module.exports = {
+  extends: 'google',
+  parserOptions: {
+    ecmaVersion: 3
+  },
+  rules: Object.assign(
+    {},
+    DISABLED_ES6_OPTIONS,
+    SHAREDB_RULES
+  )
+};

.github/workflows/test.yml

@@ -31,6 +31,8 @@ jobs:
         node-version: ${{ matrix.node }}
     - name: Install
       run: npm install
+    - name: Lint
+      run: npm run lint
     - name: Test
       run: npm run test-cover
     - name: Coveralls

package.json

@@ -11,10 +11,13 @@
   "devDependencies": {
     "chai": "^4.2.0",
     "coveralls": "^3.0.7",
+    "eslint": "^7.23.0",
+    "eslint-config-google": "^0.14.0",
     "mocha": "^6.2.2",
     "nyc": "^14.1.1"
   },
   "scripts": {
+    "lint": "./node_modules/.bin/eslint --ignore-path .gitignore '**/*.js'",
     "test": "mocha",
     "test-cover": "nyc --temp-dir=coverage -r text -r lcov npm test"
   },

test/test.js

@@ -1,5 +1,5 @@
-var RedisPubSub = require('../index');
+var redisPubSub = require('../index');
 
 require('sharedb/test/pubsub')(function(callback) {
-  callback(null, RedisPubSub());
+  callback(null, redisPubSub());
 });