.eslintrc

{
  "extends": [
    "standard",
    "standard-jsx",
    "standard-react",
    "prettier",
    "prettier/react",
    "prettier/standard",
    "plugin:jsx-a11y/recommended"
  ],
  "plugins": [
    "jsx-a11y",
    "mocha",
    "chai-expect",
    "chai-friendly"
  ],
  "parser": "babel-eslint",
  "env": {
    "browser": true,
    "mocha": true
  },
  "settings": {
    // Tell eslint-plugin-react to detect which version of React we are using
    "react": {
      "version": "detect"
    }
  },
  "rules": {
    // Fix conflict between prettier & standard by overriding to prefer
    // double quotes
    "jsx-quotes": ["error", "prefer-double"],

    // Override weird behaviour of jsx-a11y label-has-for (says labels must be
    // nested *and* have for/id attributes)
    "jsx-a11y/label-has-for": [
      "error",
      {
        "required": {
          "some": [
            "nesting",
            "id"
          ]
        }
      }
    ],

    // Swap the no-unused-expressions rule with a more chai-friendly one
    "no-unused-expressions": 0,
    "chai-friendly/no-unused-expressions": "error"
  },
  "overrides": [
    {
      // Test specific rules
      "files": ["**/test/*/src/**/*.js"],
      "globals": {
        "expect": true
      },
      "rules": {
        // mocha-specific rules
        "mocha/handle-done-callback": "error",
        "mocha/no-exclusive-tests": "error",
        "mocha/no-global-tests": "error",
        "mocha/no-identical-title": "error",
        "mocha/no-nested-tests": "error",
        "mocha/no-pending-tests": "error",
        "mocha/no-skipped-tests": "error",
        "mocha/no-mocha-arrows": "error",

        // chai-specific rules
        "chai-expect/missing-assertion": "error",
        "chai-expect/terminating-properties": "error",

        // prefer-arrow-callback applies to all callbacks, not just ones in mocha tests.
        // we don't enforce this at the top-level - just in tests to manage `this` scope
        // based on mocha's context mechanism
        "mocha/prefer-arrow-callback": "error"
      }
    },
    {
      // Frontend test specific rules
      "files": ["**/test/frontend/**/*.js"],
      "globals": {
        "expect": true,
        "define": true,
        "$": true
      }
    },
    {
      // Backend specific rules
      "files": ["**/app/src/**/*.js"],
      "rules": {
        // don't allow console.log in backend code
        "no-console": "error"
      }
    },
    {
      // Frontend specific rules
      "files": ["**/frontend/js/**/*.js"],
      "globals": {
        "define": true,
        "$": true,
        "angular": true,
        "_": true,
        "ace": true,
        "ga": true,
        "Raven": true, // Backwards compat for Sentry reporting
        "sl_console": true,
        "sl_debugging": true,
        // Injected in layout.pug
        "user_id": true,
        "ExposedSettings": true
      }
    }
  ]
}