.eslintrc.json

{
    "env": {
        "browser": true,
        // "commonjs": true,
        // "es6": true,
        "es2020": true,
        "jest": true,
        "node": true, // For jest, config files, etc...
        "amd": true,
        "mocha": true
    },

    "parser": "@typescript-eslint/parser",

    "parserOptions": {
        // Configure the parser with the tsconfig file in the root project
        // (or rather an extended version that add peripheral files such as rollup.config.js
        // so that eslint doesn't complain that they are not in the project)
        "project": "./tsconfig.eslint.json",

        // "ecmaFeatures": { "jsx": false }, // default
        "ecmaVersion": 2020,
        // "sourceType": "module" // Allow the use of import
        "extraFileExtensions": [".less"]
    },

    "extends": [
        // Uses the recommended rules for Typescript
        "plugin:@typescript-eslint/recommended",
        "prettier/@typescript-eslint", // Uses eslint-config-prettier to disable ESLint rules from @typescript-eslint/eslint-plugin that would conflict with prettier
        // Disable rules that conflict with prettier
        // See https://prettier.io/docs/en/integrating-with-linters.html
        "plugin:prettier/recommended"

        // "plugin:no-unsanitized/DOM"
    ],

    // Note:
    // "off" or 0 - turn the rule off
    // "warn" or 1 - turn the rule on as a warning (doesn’t affect exit code)
    // "error" or 2 - turn the rule on as an error (exit code is 1 when triggered)
    // See http://eslint.org/docs/rules/
    "rules": {
        // "no-unsanitized/method": [
        //     "warn",
        //     {
        //         // "disableDefault": true,
        //         "escape": {
        //             "methods": [
        //                 "createHTML",
        //                 "mathfield.config.createHTML",
        //                 "MathfieldPrivate.config.createHTML"
        //             ]
        //         }
        //     }
        // ],
        "no-restricted-globals": [
            "error",
            "postMessage",
            "blur",
            "focus",
            "close",
            "frames",
            "self",
            "parent",
            "opener",
            "top",
            "length",
            "closed",
            "location",
            "origin",
            "name",
            "locationbar",
            "menubar",
            "personalbar",
            "scrollbars",
            "statusbar",
            "toolbar",
            "status",
            "frameElement",
            // "navigator",
            "customElements",
            "external",
            "screen",
            "innerWidth",
            "innerHeight",
            "scrollX",
            "pageXOffset",
            "scrollY",
            "pageYOffset",
            "screenX",
            "screenY",
            "outerWidth",
            "outerHeight",
            "devicePixelRatio",
            "clientInformation",
            "screenLeft",
            "screenTop",
            "defaultStatus",
            "defaultstatus",
            "styleMedia",
            "onanimationend",
            "onanimationiteration",
            "onanimationstart",
            "onsearch",
            "ontransitionend",
            "onwebkitanimationend",
            "onwebkitanimationiteration",
            "onwebkitanimationstart",
            "onwebkittransitionend",
            "isSecureContext",
            "onabort",
            "onblur",
            "oncancel",
            "oncanplay",
            "oncanplaythrough",
            "onchange",
            "onclick",
            "onclose",
            "oncontextmenu",
            "oncuechange",
            "ondblclick",
            "ondrag",
            "ondragend",
            "ondragenter",
            "ondragleave",
            "ondragover",
            "ondragstart",
            "ondrop",
            "ondurationchange",
            "onemptied",
            "onended",
            "onerror",
            "onfocus",
            "oninput",
            "oninvalid",
            "onkeydown",
            "onkeypress",
            "onkeyup",
            "onload",
            "onloadeddata",
            "onloadedmetadata",
            "onloadstart",
            "onmousedown",
            "onmouseenter",
            "onmouseleave",
            "onmousemove",
            "onmouseout",
            "onmouseover",
            "onmouseup",
            "onmousewheel",
            "onpause",
            "onplay",
            "onplaying",
            "onprogress",
            "onratechange",
            "onreset",
            "onresize",
            "onscroll",
            "onseeked",
            "onseeking",
            "onselect",
            "onstalled",
            "onsubmit",
            "onsuspend",
            "ontimeupdate",
            "ontoggle",
            "onvolumechange",
            "onwaiting",
            "onwheel",
            "onauxclick",
            "ongotpointercapture",
            "onlostpointercapture",
            "onpointerdown",
            "onpointermove",
            "onpointerup",
            "onpointercancel",
            "onpointerover",
            "onpointerout",
            "onpointerenter",
            "onpointerleave",
            "onafterprint",
            "onbeforeprint",
            "onbeforeunload",
            "onhashchange",
            "onlanguagechange",
            "onmessage",
            "onmessageerror",
            "onoffline",
            "ononline",
            "onpagehide",
            "onpageshow",
            "onpopstate",
            "onrejectionhandled",
            "onstorage",
            "onunhandledrejection",
            "onunload",
            "performance",
            "stop",
            "open",
            "print",
            "captureEvents",
            "releaseEvents",
            "getComputedStyle",
            "matchMedia",
            "moveTo",
            "moveBy",
            "resizeTo",
            "resizeBy",
            "getSelection",
            "find",
            "createImageBitmap",
            "scroll",
            "scrollTo",
            "scrollBy",
            "onappinstalled",
            "onbeforeinstallprompt",
            "crypto",
            "ondevicemotion",
            "ondeviceorientation",
            "ondeviceorientationabsolute",
            "indexedDB",
            "webkitStorageInfo",
            "chrome",
            "visualViewport",
            "speechSynthesis",
            "webkitRequestFileSystem",
            "webkitResolveLocalFileSystemURL",
            "openDatabase"
        ],

        // Turn off rules that are Typescript specific
        // (they are turned on later in the "overrides" section)
        "@typescript-eslint/explicit-module-boundary-types": "off",

        "prettier/prettier": [
            "error",
            {
                "endOfLine": "auto"
            }
        ],

        // note you must disable the base rule as it can report incorrect errors
        "indent": "off",

        "no-const-assign": "warn",
        "no-this-before-super": "warn",
        // "no-undef": "warn",
        "no-unreachable": "warn",
        "no-unused-vars": ["warn", { "argsIgnorePattern": "^_" }],
        "@typescript-eslint/no-unused-vars": [
            "error",
            {
                "argsIgnorePattern": "^_"
                // "varsIgnorePattern": "^_",
                // "vars": "all",
                // "args": "after-used",
                // "ignoreRestSiblings": false
            }
        ],

        "constructor-super": "warn",

        "block-scoped-var": "error",

        "array-bracket-spacing": ["error", "never"],
        "block-spacing": ["error", "always"],
        "brace-style": ["warn", "1tbs", { "allowSingleLine": true }],
        "prefer-const": "warn",

        "valid-typeof": "error",
        "consistent-return": "error",
        "curly": ["warn", "multi-line"],
        "eqeqeq": ["error", "smart"],
        "guard-for-in": "warn",
        // "max-len": "warn",
        "new-cap": "warn",
        "no-bitwise": "off",
        "no-console": "off",
        "no-dupe-class-members": "off", // Support TypeScritp polymorphism
        "no-else-return": "warn",
        "no-eval": "error",
        "no-fallthrough": "error",
        "no-invalid-this": "warn",
        "no-lone-blocks": "warn",
        "no-return-assign": ["warn", "always"],
        "no-redeclare": "off",
        "no-self-compare": "error",
        "no-sequences": "warn",
        "no-unneeded-ternary": "warn",
        "no-unused-expressions": "warn",
        "no-useless-call": "warn",
        "no-var": "error",
        "no-with": "error",
        // "vars-on-top": "warn",
        "no-delete-var": "warn",
        "no-mixed-spaces-and-tabs": ["warn", "smart-tabs"],
        "require-jsdoc": "off",
        "space-infix-ops": ["error", { "int32Hint": false }],

        "no-trailing-spaces": [1, { "skipBlankLines": true }]
    },
    "overrides": [
        {
            // Typescript-specific rules
            "files": ["*.ts"],
            "rules": {
                // "@typescript-eslint/prefer-optional-chain": "warn",
                "@typescript-eslint/prefer-nullish-coalescing": "warn",

                "@typescript-eslint/naming-convention": [
                    "warn",
                    {
                        "selector": "typeParameter",
                        "format": ["PascalCase"]
                    }
                ],
                "@typescript-eslint/no-non-null-assertion": "off",
                "@typescript-eslint/no-use-before-define": [
                    "error",
                    {
                        "functions": false,
                        "classes": false,
                        "variables": false,
                        "typedefs": false
                    }
                ],
                "@typescript-eslint/no-this-alias": [
                    "error",
                    {
                        "allowedNames": ["self", "that"] // Allow `const self = this`; `[]` by default
                    }
                ],
                "@typescript-eslint/no-for-in-array": "error",

                "@typescript-eslint/explicit-function-return-type": "off",
                "@typescript-eslint/explicit-module-boundary-types": "warn",
                "@typescript-eslint/no-unnecessary-type-arguments": "warn",
                // "@typescript-eslint/typedef": [
                //     "warn",
                //     {
                //         "parameter": true,
                //         "arrowParameter": false,
                //         "variableDeclaration": false
                //     }
                // ],

                "@typescript-eslint/array-type": [
                    "warn",
                    { "default": "array" }
                ],

                "@typescript-eslint/no-explicit-any": "off"
            }
        }
    ]
}