Issue 3692 - Add base ESLint configuration

eslint-config-eyeo/index.js

Index: eslint-config-eyeo/index.js
diff --git a/eslint-config-eyeo/index.js b/eslint-config-eyeo/index.js
new file mode 100644
index 0000000000000000000000000000000000000000..e7dff51d64a2a0c20a49b75bb5972fd787198428
--- /dev/null
+++ b/eslint-config-eyeo/index.js
@@ -0,0 +1,114 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2017 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* eslint-env commonjs */
+
+"use strict";
+
+module.exports = {
+  extends: "eslint:recommended",
+  env: {
+    es6: true
+  },
+  rules: {
+    "array-bracket-spacing": "error",
+    "arrow-spacing": "error",
+    "block-scoped-var": "error",
+    "block-spacing": "error",
+    "brace-style": ["error", "allman", {allowSingleLine: true}],
+    "camelcase": ["error", {properties: "never"}],
+    "comma-dangle": "error",
+    "comma-spacing": "error",
+    "comma-style": "error",
+    "computed-property-spacing": "error",
+    "curly": ["error", "multi-or-nest", "consistent"],

[Wladimir Palant, 2017/02/14 12:43:20]

As Felix mentioned already, I do not really consider "consistent" necessary
here, nor does it match our current programming style. Since nobody seems to
feel strongly about this, I suggest we remove it.

[kzar, 2017/02/15 05:24:22]

Done.

+    "eol-last": "error",
+    "func-call-spacing": "error",
+    "indent": ["error", 2, {SwitchCase: 1, ArrayExpression: "first"}],
+    "key-spacing": "error",
+    "keyword-spacing": "error",
+    "linebreak-style": "error",
+    "lines-around-directive": "error",
+    "max-len": ["error", 80, {ignoreUrls: true}],
+    "new-parens": "error",
+    "no-array-constructor": "error",
+    "no-caller": "error",
+    "no-case-declarations": "off",
+    "no-catch-shadow": "error",
+    "no-cond-assign": "off",
+    "no-console": ["error", {allow: ["warn", "error", "trace"]}],
+    "no-control-regex": "off",
+    "no-else-return": "error",
+    "no-empty": ["error", {allowEmptyCatch: true}],

[Wladimir Palant, 2017/02/14 12:43:20]

For reference: the idea is that empty catch blocks have at least a comment
explaining what kind of errors is expected there and why we aren't handling
them. So IMHO the goal should be to remove allowEmptyCatch here again - but we
will need to remove this pattern from the existing codebase first.

[kzar, 2017/02/15 05:24:22]

Fair enough, I don't mind if empty catch blocks are allowed when they're
commented. Done.

[Sebastian Noack, 2017/02/15 10:35:24]

I also prefer to keep the allowEmptyCatch option (for now). FWIW, I'm not even
convinced that every empty catch block should have a comment. Sometimes it seems
quite obvious what error is expected and why it is ignored. And I'm generally
opposed to add redundant comments that doesn't add any information that aren't
already clear from the source code.

[kzar, 2017/02/15 11:45:19]

OK, since Wladimir didn't mind either way and you prefer this I've added it back
again.

+    "no-eval": "error",
+    "no-extra-bind": "error",
+    "no-extra-label": "error",
+    "no-implied-eval": "error",
+    "no-labels": ["error", {allowLoop: true}],
+    "no-lone-blocks": "error",
+    "no-lonely-if": "error",
+    "no-multi-spaces": "error",
+    "no-new-func": "error",
+    "no-new-object": "error",
+    "no-proto": "error",
+    "no-self-compare": "error",
+    "no-shadow": "error",
+    "no-trailing-spaces": "error",
+    "no-unneeded-ternary": "error",
+    "no-unused-vars": "off",
+    "no-useless-computed-key": "error",
+    "no-useless-concat": "error",
+    "no-useless-escape": "error",
+    "no-useless-return": "error",
+    "no-var": "error",
+    "no-warning-comments": "error",
+    "no-whitespace-before-property": "error",
+    "no-with": "error",
+    "object-curly-spacing": "error",
+    "object-shorthand": ["error", "always", {
+      avoidExplicitReturnArrows: true
+    }],
+    "one-var": ["error", "never"],
+    "operator-assignment": "error",
+    "operator-linebreak": "error",
+    "padded-blocks": ["error", "never"],
+    "prefer-arrow-callback": "error",
+    "prefer-destructuring": ["error", {array: false}],
+    "prefer-numeric-literals": "error",
+    "prefer-rest-params": "error",
+    "prefer-spread": "error",
+    "quote-props": ["error", "consistent-as-needed"],
+    "quotes": ["error", "double", {avoidEscape: true}],
+    "radix": "error",
+    "rest-spread-spacing": "error",
+    "semi": "error",
+    "semi-spacing": "error",
+    "space-before-function-paren": ["error", "never"],
+    "space-in-parens": "error",
+    "space-infix-ops": "error",
+    "space-unary-ops": "error",
+    "spaced-comment": "error",
+    "strict": ["error", "global"],
+    "valid-jsdoc": ["error", {
+      requireParamDescription: false,
+      requireReturn: false,
+      requireReturnDescription: false
+    }],
+    "yield-star-spacing": "error",
+    "yoda": "error"
+  }
+};