@tangany/eslint-config/rules/best-practices.js

Tangany's ESLint config

import TSESLint from "typescript-eslint";

export default TSESLint.config(
  {
    rules: {
      // enforces getter/setter pairs in objects
      // https://eslint.org/docs/rules/accessor-pairs
      "accessor-pairs": "off",

      // enforces return statements in callbacks of array's methods
      // https://eslint.org/docs/rules/array-callback-return
      "array-callback-return": ["error", { allowImplicit: true }],

      // treat var statements as if they were block scoped
      // https://eslint.org/docs/rules/block-scoped-var
      "block-scoped-var": "error",

      // https://eslint.org/docs/latest/rules/camelcase
      camelcase: ["off", { properties: "never" }],

      // specify the maximum cyclomatic complexity allowed in a program
      // https://eslint.org/docs/rules/complexity
      complexity: ["off", 20],

      // enforce that class methods use "this"
      // https://eslint.org/docs/rules/class-methods-use-this
      "class-methods-use-this": [
        "off",
        {
          exceptMethods: [],
        },
      ],

      // require return statements to either always or never specify values
      // https://eslint.org/docs/rules/consistent-return
      "consistent-return": "error",

      // specify curly brace conventions for all control statements
      // https://eslint.org/docs/rules/curly
      curly: ["error", "multi-line"],

      // require default case in switch statements
      // https://eslint.org/docs/rules/default-case
      "default-case": ["error", { commentPattern: "^no default$" }],

      // Enforce default clauses in switch statements to be last
      // https://eslint.org/docs/rules/default-case-last
      "default-case-last": "error",

      // enforces consistent newlines before or after dots
      // https://eslint.org/docs/rules/dot-location
      "dot-location": ["error", "property"],

      // require the use of === and !==
      // https://eslint.org/docs/rules/eqeqeq
      eqeqeq: ["error", "always", { null: "ignore" }],

      // Require grouped accessor pairs in object literals and classes
      // https://eslint.org/docs/rules/grouped-accessor-pairs
      "grouped-accessor-pairs": "error",

      // make sure for-in loops have an if statement
      // https://eslint.org/docs/rules/guard-for-in
      "guard-for-in": "error",

      // https://eslint.org/docs/latest/rules/logical-assignment-operators
      "logical-assignment-operators": [
        "error",
        "always",
        { enforceForIfStatements: true },
      ],

      // enforce a maximum number of classes per file
      // https://eslint.org/docs/rules/max-classes-per-file
      "max-classes-per-file": "off",

      // disallow the use of alert, confirm, and prompt
      // https://eslint.org/docs/rules/no-alert
      "no-alert": "warn",

      // disallow use of arguments.caller or arguments.callee
      // https://eslint.org/docs/rules/no-caller
      "no-caller": "error",

      // Disallow returning value in constructor
      // https://eslint.org/docs/rules/no-constructor-return
      "no-constructor-return": "error",

      // disallow division operators explicitly at beginning of regular expression
      // https://eslint.org/docs/rules/no-div-regex
      "no-div-regex": "off",

      // disallow else after a return in an if
      // https://eslint.org/docs/rules/no-else-return
      "no-else-return": ["error", { allowElseIf: false }],

      // disallow comparisons to null without a type-checking operator
      // https://eslint.org/docs/rules/no-eq-null
      "no-eq-null": "off",

      // disallow use of eval()
      // https://eslint.org/docs/rules/no-eval
      "no-eval": "error",

      // disallow adding to native types
      // https://eslint.org/docs/rules/no-extend-native
      "no-extend-native": "error",

      // disallow unnecessary function binding
      // https://eslint.org/docs/rules/no-extra-bind
      "no-extra-bind": "error",

      // disallow Unnecessary Labels
      // https://eslint.org/docs/rules/no-extra-label
      "no-extra-label": "error",

      // disallow the use of leading or trailing decimal points in numeric literals
      // https://eslint.org/docs/rules/no-floating-decimal
      "no-floating-decimal": "error",

      // disallow implicit type conversions
      // https://eslint.org/docs/rules/no-implicit-coercion
      "no-implicit-coercion": [
        "off",
        {
          boolean: false,
          number: true,
          string: true,
          allow: [],
        },
      ],

      // disallow var and named functions in global scope
      // https://eslint.org/docs/rules/no-implicit-globals
      "no-implicit-globals": "off",

      // disallow usage of __iterator__ property
      // https://eslint.org/docs/rules/no-iterator
      "no-iterator": "error",

      // disallow use of labels for anything other than loops and switches
      // https://eslint.org/docs/rules/no-labels
      "no-labels": ["error", { allowLoop: false, allowSwitch: false }],

      // disallow unnecessary nested blocks
      // https://eslint.org/docs/rules/no-lone-blocks
      "no-lone-blocks": "error",

      // disallow use of multiple spaces
      // https://eslint.org/docs/rules/no-multi-spaces
      "no-multi-spaces": [
        "error",
        {
          ignoreEOLComments: false,
        },
      ],

      // disallow use of multiline strings
      // https://eslint.org/docs/rules/no-multi-str
      "no-multi-str": "error",

      // disallow use of new operator when not part of the assignment or comparison
      // https://eslint.org/docs/rules/no-new
      "no-new": "error",

      // https://eslint.org/docs/latest/rules/no-new-func
      "no-new-func": "error",

      // disallows creating new instances of String, Number, and Boolean
      // https://eslint.org/docs/rules/no-new-wrappers
      "no-new-wrappers": "error",

      // Disallow calls to the Object constructor without an argument
      // https://eslint.org/docs/latest/rules/no-object-constructor
      "no-object-constructor": "error",

      // disallow use of octal escape sequences in string literals, such as
      // var foo = 'Copyright \251';
      // https://eslint.org/docs/rules/no-octal-escape
      "no-octal-escape": "error",

      // disallow reassignment of function parameters
      // disallow parameter object manipulation except for specific exclusions
      // rule: https://eslint.org/docs/rules/no-param-reassign.html
      "no-param-reassign": [
        "warn",
        {
          props: true,
          ignorePropertyModificationsFor: [
            "acc", // for reduce accumulators
            "accumulator", // for reduce accumulators
            "e", // for e.returnvalue
            "ctx", // for Koa routing
            "context", // for Koa routing
            "req", // for Express requests
            "request", // for Express requests
            "res", // for Express responses
            "response", // for Express responses
            "$scope", // for Angular 1 scopes
            "staticContext", // for ReactRouter context
          ],
        },
      ],

      // disallow usage of __proto__ property
      // https://eslint.org/docs/rules/no-proto
      "no-proto": "error",

      // disallow certain object properties
      // https://eslint.org/docs/rules/no-restricted-properties
      "no-restricted-properties": [
        "error",
        {
          object: "arguments",
          property: "callee",
          message: "arguments.callee is deprecated",
        },
        {
          object: "global",
          property: "isFinite",
          message: "Please use Number.isFinite instead",
        },
        {
          object: "self",
          property: "isFinite",
          message: "Please use Number.isFinite instead",
        },
        {
          object: "window",
          property: "isFinite",
          message: "Please use Number.isFinite instead",
        },
        {
          object: "global",
          property: "isNaN",
          message: "Please use Number.isNaN instead",
        },
        {
          object: "self",
          property: "isNaN",
          message: "Please use Number.isNaN instead",
        },
        {
          object: "window",
          property: "isNaN",
          message: "Please use Number.isNaN instead",
        },
        {
          property: "__defineGetter__",
          message: "Please use Object.defineProperty instead.",
        },
        {
          property: "__defineSetter__",
          message: "Please use Object.defineProperty instead.",
        },
        {
          object: "Math",
          property: "pow",
          message: "Use the exponentiation operator (**) instead.",
        },
      ],

      // disallow use of assignment in return statement
      // https://eslint.org/docs/rules/no-return-assign
      "no-return-assign": ["error", "always"],

      // disallow use of `javascript:` urls.
      // https://eslint.org/docs/rules/no-script-url
      "no-script-url": "error",

      // disallow comparisons where both sides are exactly the same
      // https://eslint.org/docs/rules/no-self-compare
      "no-self-compare": "error",

      // disallow use of comma operator
      // https://eslint.org/docs/rules/no-sequences
      "no-sequences": "error",

      // disallow unmodified conditions of loops
      // https://eslint.org/docs/rules/no-unmodified-loop-condition
      "no-unmodified-loop-condition": "off",

      // disallow unnecessary .call() and .apply()
      // https://eslint.org/docs/rules/no-useless-call
      "no-useless-call": "off",

      // disallow useless string concatenation
      // https://eslint.org/docs/rules/no-useless-concat
      "no-useless-concat": "error",

      // disallow redundant return; keywords
      // https://eslint.org/docs/rules/no-useless-return
      "no-useless-return": "error",

      // disallow use of void operator
      // https://eslint.org/docs/rules/no-void
      "no-void": "error",

      // disallow usage of configurable warning terms in comments: e.g. todo
      // https://eslint.org/docs/rules/no-warning-comments
      "no-warning-comments": [
        "off",
        { terms: ["todo", "fixme", "xxx"], location: "start" },
      ],

      // require using Error objects as Promise rejection reasons
      // https://eslint.org/docs/rules/prefer-promise-reject-errors
      "prefer-promise-reject-errors": ["error", { allowEmptyReject: true }],

      // Suggest using named capture group in regular expression
      // https://eslint.org/docs/rules/prefer-named-capture-group
      "prefer-named-capture-group": "off",

      // https://eslint.org/docs/latest/rules/prefer-object-has-own
      "prefer-object-has-own": "error",

      // https://eslint.org/docs/rules/prefer-regex-literals
      "prefer-regex-literals": [
        "error",
        {
          disallowRedundantWrapping: true,
        },
      ],

      // require use of the second argument for parseInt()
      // https://eslint.org/docs/rules/radix
      radix: "error",

      // Enforce the use of u flag on RegExp
      // https://eslint.org/docs/rules/require-unicode-regexp
      "require-unicode-regexp": "off",

      // requires to declare all vars on top of their containing scope
      // https://eslint.org/docs/rules/vars-on-top
      "vars-on-top": "error",

      // require immediate function invocation to be wrapped in parentheses
      // https://eslint.org/docs/rules/wrap-iife.html
      "wrap-iife": ["error", "outside", { functionPrototypeMethods: false }],

      // require or disallow Yoda conditions
      // https://eslint.org/docs/rules/yoda
      yoda: "error",
    },
  },
);