{
  "root": true,
  "extends": [
    "eslint:recommended",
    "plugin:react/recommended",
    "plugin:react-hooks/recommended",
    "plugin:jsx-a11y/recommended",
    "standard",
    "standard-jsx",
    "standard-react",
    "prettier",
    "prettier/react",
    "prettier/standard"
  ],
  "plugins": [
    "jsx-a11y",
    "mocha",
    "chai-expect",
    "chai-friendly"
  ],
  "env": {
    "browser": true,
    "mocha": true,
    "node": true,
    "es2020": true
  },
  "parserOptions": {
    "sourceType": "module",
    "ecmaFeatures": {
      "jsx": true
    }
  },
  "settings": {
    // Tell eslint-plugin-react to detect which version of React we are using
    "react": {
      "version": "detect"
    }
  },
  "rules": {
    // Swap the no-unused-expressions rule with a more chai-friendly one
    "no-unused-expressions": "off",
    "chai-friendly/no-unused-expressions": "error",

    // Disable some rules after upgrading ESLint
    // TODO: re-enable and fix
    "no-prototype-builtins": "off",
    "no-var": "off",
    "prefer-const": "off",
    "prefer-regex-literals": "off",
    "array-callback-return": "off",
    "no-unreachable-loop": "off",
    "no-loss-of-precision": "off",

    "node/no-callback-literal": "off",
    "node/no-deprecated-api": "off",
    "node/handle-callback-err": "off",
    "node/no-path-concat": "off",

    "react/display-name": "off",
    "react/no-unescaped-entities": "off",
    "react/no-unused-prop-types": "off",
    "react/jsx-no-target-blank": "off",
    "react/jsx-handler-names": "off"
  },
  "overrides": [
    // NOTE: changing paths may require updating them in the Makefile too.
    {
      // Test specific rules
      "files": ["**/test/*/src/**/*.js", "**/test/**/*.test.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/karma/**/*.js"],
      "globals": {
        "expect": true,
        "$": true
      }
    },
    {
      // Backend specific rules
      "files": ["**/app/src/**/*.js"],
      "rules": {
        // don't allow console.log in backend code
        "no-console": "error"
      }
    },
    {
      // Frontend specific rules
      "files": ["**/frontend/js/**/*.js"],
      "globals": {
        "$": true,
        "angular": true,
        "ace": true,
        "ga": true,
        "sl_console": true,
        "sl_debugging": true,
        // Injected in layout.pug
        "user_id": true,
        "ExposedSettings": true
      },
      "rules": {
        // Prevent usage of legacy string refs
        "react/no-string-refs": "error",

        // Prevent curly braces around strings (as they're unnecessary)
        "react/jsx-curly-brace-presence": ["error", {
          "props": "never",
          "children": "never"
        }],

        // 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"
              ]
            }
          }
        ]
      }
    }
  ]
}