eslint/tests/lib/rules/no-underscore-dangle.js

   1 /**
   2  * @fileoverview Test for no-underscore-dangle rule
   3  * @author Matt DuVall <http://www.mattduvall.com>
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Requirements
  10 //------------------------------------------------------------------------------
  11
  12 const rule = require("../../../lib/rules/no-underscore-dangle"),
  13     { RuleTester } = require("../../../lib/rule-tester");
  14
  15 //------------------------------------------------------------------------------
  16 // Tests
  17 //------------------------------------------------------------------------------
  18
  19 const ruleTester = new RuleTester();
  20
  21 ruleTester.run("no-underscore-dangle", rule, {
  22     valid: [
  23         "var foo_bar = 1;",
  24         "function foo_bar() {}",
  25         "foo.bar.__proto__;",
  26         "console.log(__filename); console.log(__dirname);",
  27         "var _ = require('underscore');",
  28         "var a = b._;",
  29         "function foo(_bar) {}",
  30         "function foo(bar_) {}",
  31         "(function _foo() {})",
  32         { code: "function foo(_bar) {}", options: [{}] },
  33         { code: "function foo( _bar = 0) {}", parserOptions: { ecmaVersion: 6 } },
  34         { code: "const foo = { onClick(_bar) { } }", parserOptions: { ecmaVersion: 6 } },
  35         { code: "const foo = { onClick(_bar = 0) { } }", parserOptions: { ecmaVersion: 6 } },
  36         { code: "const foo = (_bar) => {}", parserOptions: { ecmaVersion: 6 } },
  37         { code: "const foo = (_bar = 0) => {}", parserOptions: { ecmaVersion: 6 } },
  38         { code: "function foo( ..._bar) {}", parserOptions: { ecmaVersion: 6 } },
  39         { code: "const foo = (..._bar) => {}", parserOptions: { ecmaVersion: 6 } },
  40         { code: "const foo = { onClick(..._bar) { } }", parserOptions: { ecmaVersion: 6 } },
  41         { code: "export default function() {}", parserOptions: { ecmaVersion: 6, sourceType: "module" } },
  42         { code: "var _foo = 1", options: [{ allow: ["_foo"] }] },
  43         { code: "var __proto__ = 1;", options: [{ allow: ["__proto__"] }] },
  44         { code: "foo._bar;", options: [{ allow: ["_bar"] }] },
  45         { code: "function _foo() {}", options: [{ allow: ["_foo"] }] },
  46         { code: "this._bar;", options: [{ allowAfterThis: true }] },
  47         { code: "class foo { constructor() { super._bar; } }", options: [{ allowAfterSuper: true }], parserOptions: { ecmaVersion: 6 } },
  48         { code: "class foo { _onClick() { } }", parserOptions: { ecmaVersion: 6 } },
  49         { code: "class foo { onClick_() { } }", parserOptions: { ecmaVersion: 6 } },
  50         { code: "const o = { _onClick() { } }", parserOptions: { ecmaVersion: 6 } },
  51         { code: "const o = { onClick_() { } }", parserOptions: { ecmaVersion: 6 } },
  52         { code: "const o = { _onClick() { } }", options: [{ allow: ["_onClick"], enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 } },
  53         { code: "const o = { _foo: 'bar' }", parserOptions: { ecmaVersion: 6 } },
  54         { code: "const o = { foo_: 'bar' }", parserOptions: { ecmaVersion: 6 } },
  55         { code: "this.constructor._bar", options: [{ allowAfterThisConstructor: true }] },
  56         { code: "const foo = { onClick(bar) { } }", parserOptions: { ecmaVersion: 6 } },
  57         { code: "const foo = (bar) => {}", parserOptions: { ecmaVersion: 6 } },
  58         { code: "function foo(_bar) {}", options: [{ allowFunctionParams: true }] },
  59         { code: "function foo( _bar = 0) {}", options: [{ allowFunctionParams: true }], parserOptions: { ecmaVersion: 6 } },
  60         { code: "const foo = { onClick(_bar) { } }", options: [{ allowFunctionParams: true }], parserOptions: { ecmaVersion: 6 } },
  61         { code: "const foo = (_bar) => {}", options: [{ allowFunctionParams: true }], parserOptions: { ecmaVersion: 6 } },
  62         { code: "function foo(bar) {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 } },
  63         { code: "const foo = { onClick(bar) { } }", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 } },
  64         { code: "const foo = (bar) => {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 } },
  65         { code: "function foo(_bar) {}", options: [{ allowFunctionParams: false, allow: ["_bar"] }] },
  66         { code: "const foo = { onClick(_bar) { } }", options: [{ allowFunctionParams: false, allow: ["_bar"] }], parserOptions: { ecmaVersion: 6 } },
  67         { code: "const foo = (_bar) => {}", options: [{ allowFunctionParams: false, allow: ["_bar"] }], parserOptions: { ecmaVersion: 6 } },
  68         { code: "function foo([_bar]) {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 } },
  69         { code: "function foo([_bar] = []) {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 } },
  70         { code: "function foo( { _bar }) {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 } },
  71         { code: "function foo( { _bar = 0 } = {}) {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 } },
  72         { code: "function foo(...[_bar]) {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 2016 } },
  73         { code: "const [_foo] = arr", parserOptions: { ecmaVersion: 6 } },
  74         { code: "const [_foo] = arr", options: [{}], parserOptions: { ecmaVersion: 6 } },
  75         { code: "const [_foo] = arr", options: [{ allowInArrayDestructuring: true }], parserOptions: { ecmaVersion: 6 } },
  76         { code: "const [foo, ...rest] = [1, 2, 3]", options: [{ allowInArrayDestructuring: false }], parserOptions: { ecmaVersion: 2022 } },
  77         { code: "const [foo, _bar] = [1, 2, 3]", options: [{ allowInArrayDestructuring: false, allow: ["_bar"] }], parserOptions: { ecmaVersion: 2022 } },
  78         { code: "const { _foo } = obj", parserOptions: { ecmaVersion: 6 } },
  79         { code: "const { _foo } = obj", options: [{}], parserOptions: { ecmaVersion: 6 } },
  80         { code: "const { _foo } = obj", options: [{ allowInObjectDestructuring: true }], parserOptions: { ecmaVersion: 6 } },
  81         { code: "const { foo, bar: _bar } = { foo: 1, bar: 2 }", options: [{ allowInObjectDestructuring: false, allow: ["_bar"] }], parserOptions: { ecmaVersion: 2022 } },
  82         { code: "const { foo, _bar } = { foo: 1, _bar: 2 }", options: [{ allowInObjectDestructuring: false, allow: ["_bar"] }], parserOptions: { ecmaVersion: 2022 } },
  83         { code: "const { foo, _bar: bar } = { foo: 1, _bar: 2 }", options: [{ allowInObjectDestructuring: false }], parserOptions: { ecmaVersion: 2022 } },
  84         { code: "class foo { _field; }", parserOptions: { ecmaVersion: 2022 } },
  85         { code: "class foo { _field; }", options: [{ enforceInClassFields: false }], parserOptions: { ecmaVersion: 2022 } },
  86         { code: "class foo { #_field; }", parserOptions: { ecmaVersion: 2022 } },
  87         { code: "class foo { #_field; }", options: [{ enforceInClassFields: false }], parserOptions: { ecmaVersion: 2022 } },
  88         { code: "class foo { _field; }", options: [{}], parserOptions: { ecmaVersion: 2022 } }
  89     ],
  90     invalid: [
  91         { code: "var _foo = 1", errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_foo" }, type: "VariableDeclarator" }] },
  92         { code: "var foo_ = 1", errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "foo_" }, type: "VariableDeclarator" }] },
  93         { code: "function _foo() {}", errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_foo" }, type: "FunctionDeclaration" }] },
  94         { code: "function foo_() {}", errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "foo_" }, type: "FunctionDeclaration" }] },
  95         { code: "var __proto__ = 1;", errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "__proto__" }, type: "VariableDeclarator" }] },
  96         { code: "foo._bar;", errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "MemberExpression" }] },
  97         { code: "this._prop;", errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_prop" }, type: "MemberExpression" }] },
  98         { code: "class foo { constructor() { super._prop; } }", parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_prop" }, type: "MemberExpression" }] },
  99         { code: "class foo { constructor() { this._prop; } }", options: [{ allowAfterSuper: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_prop" }, type: "MemberExpression" }] },
 100         { code: "class foo { _onClick() { } }", options: [{ enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_onClick" }, type: "MethodDefinition" }] },
 101         { code: "class foo { onClick_() { } }", options: [{ enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "onClick_" }, type: "MethodDefinition" }] },
 102         { code: "const o = { _onClick() { } }", options: [{ enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_onClick" }, type: "Property" }] },
 103         { code: "const o = { onClick_() { } }", options: [{ enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "onClick_" }, type: "Property" }] },
 104         { code: "this.constructor._bar", errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "MemberExpression" }] },
 105         { code: "function foo(_bar) {}", options: [{ allowFunctionParams: false }], errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "Identifier" }] },
 106         { code: "(function foo(_bar) {})", options: [{ allowFunctionParams: false }], errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "Identifier" }] },
 107         { code: "function foo(bar, _foo) {}", options: [{ allowFunctionParams: false }], errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_foo" }, type: "Identifier" }] },
 108         { code: "const foo = { onClick(_bar) { } }", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "Identifier" }] },
 109         { code: "const foo = (_bar) => {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "Identifier" }] },
 110         { code: "function foo(_bar = 0) {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "AssignmentPattern" }] },
 111         { code: "const foo = { onClick(_bar = 0) { } }", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "AssignmentPattern" }] },
 112         { code: "const foo = (_bar = 0) => {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "AssignmentPattern" }] },
 113         { code: "function foo(..._bar) {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "RestElement" }] },
 114         { code: "const foo = { onClick(..._bar) { } }", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "RestElement" }] },
 115         { code: "const foo = (..._bar) => {}", options: [{ allowFunctionParams: false }], parserOptions: { ecmaVersion: 6 }, errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" }, type: "RestElement" }] },
 116         {
 117             code: "const [foo, _bar] = [1, 2]",
 118             options: [{ allowInArrayDestructuring: false }],
 119             parserOptions: { ecmaVersion: 2022 },
 120             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_bar" } }]
 121         }, {
 122             code: "const [_foo = 1] = arr",
 123             options: [{ allowInArrayDestructuring: false }],
 124             parserOptions: { ecmaVersion: 2022 },
 125             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_foo" } }]
 126         }, {
 127             code: "const [foo, ..._rest] = [1, 2, 3]",
 128             options: [{ allowInArrayDestructuring: false }],
 129             parserOptions: { ecmaVersion: 2022 },
 130             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_rest" } }]
 131         }, {
 132             code: "const [foo, [bar_, baz]] = [1, [2, 3]]",
 133             options: [{ allowInArrayDestructuring: false }],
 134             parserOptions: { ecmaVersion: 2022 },
 135             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "bar_" } }]
 136         }, {
 137             code: "const { _foo, bar } = { _foo: 1, bar: 2 }",
 138             options: [{ allowInObjectDestructuring: false }],
 139             parserOptions: { ecmaVersion: 2022 },
 140             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_foo" } }]
 141         }, {
 142             code: "const { _foo = 1 } = obj",
 143             options: [{ allowInObjectDestructuring: false }],
 144             parserOptions: { ecmaVersion: 2022 },
 145             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_foo" } }]
 146         }, {
 147             code: "const { bar: _foo = 1 } = obj",
 148             options: [{ allowInObjectDestructuring: false }],
 149             parserOptions: { ecmaVersion: 2022 },
 150             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_foo" } }]
 151         }, {
 152             code: "const { foo: _foo, bar } = { foo: 1, bar: 2 }",
 153             options: [{ allowInObjectDestructuring: false }],
 154             parserOptions: { ecmaVersion: 2022 },
 155             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_foo" } }]
 156         }, {
 157             code: "const { foo, ..._rest} = { foo: 1, bar: 2, baz: 3 }",
 158             options: [{ allowInObjectDestructuring: false }],
 159             parserOptions: { ecmaVersion: 2022 },
 160             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_rest" } }]
 161         }, {
 162             code: "const { foo: [_bar, { a: _a, b } ] } = { foo: [1, { a: 'a', b: 'b' }] }",
 163             options: [{ allowInArrayDestructuring: false, allowInObjectDestructuring: false }],
 164             parserOptions: { ecmaVersion: 2022 },
 165             errors: [
 166                 { messageId: "unexpectedUnderscore", data: { identifier: "_bar" } },
 167                 { messageId: "unexpectedUnderscore", data: { identifier: "_a" } }
 168             ]
 169         }, {
 170             code: "const { foo: [_bar, { a: _a, b } ] } = { foo: [1, { a: 'a', b: 'b' }] }",
 171             options: [{ allowInArrayDestructuring: true, allowInObjectDestructuring: false }],
 172             parserOptions: { ecmaVersion: 2022 },
 173             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_a" } }]
 174         }, {
 175             code: "const [{ foo: [_bar, _, { bar: _baz }] }] = [{ foo: [1, 2, { bar: 'a' }] }]",
 176             options: [{ allowInArrayDestructuring: false, allowInObjectDestructuring: false }],
 177             parserOptions: { ecmaVersion: 2022 },
 178             errors: [
 179                 { messageId: "unexpectedUnderscore", data: { identifier: "_bar" } },
 180                 { messageId: "unexpectedUnderscore", data: { identifier: "_baz" } }
 181             ]
 182         }, {
 183             code: "const { foo, bar: { baz, _qux } } = { foo: 1, bar: { baz: 3, _qux: 4 } }",
 184             options: [{ allowInObjectDestructuring: false }],
 185             parserOptions: { ecmaVersion: 2022 },
 186             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_qux" } }]
 187         }, {
 188             code: "class foo { #_bar() {} }",
 189             options: [{ enforceInMethodNames: true }],
 190             parserOptions: { ecmaVersion: 2022 },
 191             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "#_bar" } }]
 192         }, {
 193             code: "class foo { #bar_() {} }",
 194             options: [{ enforceInMethodNames: true }],
 195             parserOptions: { ecmaVersion: 2022 },
 196             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "#bar_" } }]
 197         },
 198         {
 199             code: "class foo { _field; }",
 200             options: [{ enforceInClassFields: true }],
 201             parserOptions: { ecmaVersion: 2022 },
 202             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "_field" } }]
 203         },
 204         {
 205             code: "class foo { #_field; }",
 206             options: [{ enforceInClassFields: true }],
 207             parserOptions: { ecmaVersion: 2022 },
 208             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "#_field" } }]
 209         },
 210         {
 211             code: "class foo { field_; }",
 212             options: [{ enforceInClassFields: true }],
 213             parserOptions: { ecmaVersion: 2022 },
 214             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "field_" } }]
 215         },
 216         {
 217             code: "class foo { #field_; }",
 218             options: [{ enforceInClassFields: true }],
 219             parserOptions: { ecmaVersion: 2022 },
 220             errors: [{ messageId: "unexpectedUnderscore", data: { identifier: "#field_" } }]
 221         }
 222     ]
 223 });