.eslintrc.json

// Based on https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/blob/main/lint/eslintrc-gjs.yml#L67

{
    "env": {
        "es6": true,
        "es2020": true
    },
    "extends": "eslint:recommended",
    "parserOptions": {
        "ecmaVersion": "latest"
    },
    "rules": {
        "array-bracket-newline": [
            "error",
            "consistent"
        ],
        "array-bracket-spacing": [
            "error",
            "never"
        ],
        "array-callback-return": "error",
        "arrow-parens": [
            "error",
            "as-needed"
        ],
        "arrow-spacing": "error",
        "block-scoped-var": "error",
        "block-spacing": "error",
        "comma-dangle": "error",
        "comma-spacing": [
            "error",
            {
                "before": false,
                "after": true
            }
        ],
        "comma-style": [
            "error",
            "last"
        ],
        "computed-property-spacing": "error",
        "curly": [
            "error",
            "multi-or-nest",
            "consistent"
        ],
        "dot-location": [
            "error",
            "property"
        ],
        "eol-last": "error",
        "eqeqeq": "error",
        "func-call-spacing": "error",
        "func-name-matching": "error",
        "func-style": [
            "error",
            "declaration",
            {
                "allowArrowFunctions": true
            }
        ],
        "indent": [
            "error",
            4,
            {
                "FunctionExpression": {
                    "parameters": 2
                },
                "SwitchCase": 1,
                "ignoredNodes": ["CallExpression[callee.object.name=GObject][callee.property.name=registerClass] > ClassExpression:first-child"],
                "MemberExpression": "off"

            }
        ],
        "key-spacing": [
            "error",
            {
                "beforeColon": false,
                "afterColon": true
            }
        ],
        "keyword-spacing": [
            "error",
            {
                "before": true,
                "after": true
            }
        ],
        "linebreak-style": [
            "error",
            "unix"
        ],
        "max-nested-callbacks": "error",
        "max-statements-per-line": [
            "error",
            { "max": 2 }
        ],
        "new-parens": "error",
        "no-array-constructor": "error",
        "no-await-in-loop": "error",
        "no-caller": "error",
        "no-constant-condition": [
            "error",
            { "checkLoops": false }
        ],
        "no-div-regex": "error",
        "no-empty": [
            "error",
            { "allowEmptyCatch": true }
        ],
        "no-extra-bind": "error",
        "no-extra-boolean-cast": "off",
        "no-extra-parens": [
            "error",
            "all",
            {
                "conditionalAssign": false,
                "nestedBinaryExpressions": false,
                "returnAssign": false
            }
        ],
        "no-implicit-coercion": [
            "error",
            { "allow": ["!!"] }
        ],
        "no-iterator": "error",
        "no-label-var": "error",
        "no-lonely-if": "error",
        "no-loop-func": "error",
        "no-multiple-empty-lines": "error",
        "no-multi-spaces": "error",
        "no-nested-ternary": "error",
        "no-new-object": "error",
        "no-new-wrappers": "error",
        "no-octal-escape": "error",
        "no-proto": "error",
        "no-prototype-builtins": "off",
        "no-restricted-properties": [
            "error",
            {
                "object": "imports",
                "property": "format",
                "message": "Use template strings"
            },
            {
                "object": "pkg",
                "property": "initFormat",
                "message": "Use template strings"
            },
            {
                "object": "Lang",
                "property": "copyProperties",
                "message": "Use Object.assign()"
            },
            {
                "object": "Lang",
                "property": "bind",
                "message": "Use arrow notation or Function.prototype.bind()"
            },
            {
                "object": "Lang",
                "property": "Class",
                "message": "Use ES6 classes"
            }
        ],
        "no-return-assign": "error",
        "no-return-await": "error",
        "no-self-compare": "error",
        "no-shadow": "error",
        "no-shadow-restricted-names": "error",
        "no-spaced-func": "error",
        "no-tabs": "error",
        "no-template-curly-in-string": "error",
        "no-throw-literal": "error",
        "no-trailing-spaces": "error",
        "no-undef": "error",
        "no-unneeded-ternary": "error",
        "no-unused-vars": [
            "error",
            {
                "vars": "local",
                "varsIgnorePattern": "(^unused|_$)",
                "argsIgnorePattern": "^(unused|_)"
            }
        ],
        "no-useless-call": "error",
        "no-useless-computed-key": "error",
        "no-useless-concat": "error",
        "no-useless-constructor": "error",
        "no-useless-rename": "error",
        "no-useless-return": "error",
        "no-whitespace-before-property": "error",
        "no-with": "error",
        "nonblock-statement-body-position": [
            "error",
            "below"
        ],
        "object-curly-newline": [
            "error",
            {
                "consistent": true,
                "multiline": true
            }
        ],
        "object-curly-spacing": [
            "error",
            "always"
        ],
        "object-shorthand": "error",
        "operator-assignment": "error",
        "operator-linebreak": "error",
        "padded-blocks": [
            "error",
            "never"
        ],
        "prefer-numeric-literals": "error",
        "prefer-promise-reject-errors": "error",
        "prefer-rest-params": "error",
        "prefer-spread": "error",
        "prefer-template": "error",
        "quotes": [
            "error",
            "single",
            { "avoidEscape": true }
        ],
        "require-await": "error",
        "rest-spread-spacing": "error",
        "semi": [
            "error",
            "always"
        ],
        "semi-spacing": [
            "error",
            {
                "before": false,
                "after": true
            }
        ],
        "semi-style": "error",
        "space-before-blocks": [
            "error",
            "always"
        ],
        "space-before-function-paren": [
            "error",
            {
                "named": "never",
                "anonymous": "always",
                "asyncArrow": "always"
            }
        ],
        "space-in-parens": "error",
        "space-infix-ops": [
            "error",
            { "int32Hint": false }
        ],
        "space-unary-ops": "error",
        "switch-colon-spacing": "error",
        "symbol-description": "error",
        "template-curly-spacing": "error",
        "template-tag-spacing": "error",
        "unicode-bom": "error",
        "wrap-iife": [
            "error",
            "inside"
        ],
        "yield-star-spacing": "error",
        "yoda": "error"
    },
    "globals": {
        "ARGV": "readonly",
        "Debugger": "readonly",
        "GIRepositoryGType": "readonly",
        "globalThis": "readonly",
        "global": "readonly",
        "imports": "readonly",
        "Intl": "readonly",
        "log": "readonly",
        "logError": "readonly",
        "print": "readonly",
        "printerr": "readonly",
        "window": "readonly",
        "TextEncoder": "readonly",
        "TextDecoder": "readonly"
    }
}