eslint/tests/lib/rules/init-declarations.js

   1 /**
   2  * @fileoverview A rule to control the style of variable initializations.
   3  * @author Colin Ihrig
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Requirements
  10 //------------------------------------------------------------------------------
  11
  12 const rule = require("../../../lib/rules/init-declarations"),
  13     { RuleTester } = require("../../../lib/rule-tester");
  14
  15 //------------------------------------------------------------------------------
  16 // Tests
  17 //------------------------------------------------------------------------------
  18
  19 const ruleTester = new RuleTester();
  20
  21 ruleTester.run("init-declarations", rule, {
  22     valid: [
  23         "var foo = null;",
  24         "foo = true;",
  25         "var foo = 1, bar = false, baz = {};",
  26         "function foo() { var foo = 0; var bar = []; }",
  27         "var fn = function() {};",
  28         "var foo = bar = 2;",
  29         "for (var i = 0; i < 1; i++) {}",
  30         "for (var foo in []) {}",
  31         { code: "for (var foo of []) {}", parserOptions: { ecmaVersion: 6 } },
  32         {
  33             code: "let a = true;",
  34             options: ["always"],
  35             parserOptions: { ecmaVersion: 6 }
  36         },
  37         {
  38             code: "const a = {};",
  39             options: ["always"],
  40             parserOptions: { ecmaVersion: 6 }
  41         },
  42         {
  43             code: "function foo() { let a = 1, b = false; if (a) { let c = 3, d = null; } }",
  44             options: ["always"],
  45             parserOptions: { ecmaVersion: 6 }
  46         },
  47         {
  48             code: "function foo() { const a = 1, b = true; if (a) { const c = 3, d = null; } }",
  49             options: ["always"],
  50             parserOptions: { ecmaVersion: 6 }
  51         },
  52         {
  53             code: "function foo() { let a = 1; const b = false; var c = true; }",
  54             options: ["always"],
  55             parserOptions: { ecmaVersion: 6 }
  56         },
  57         {
  58             code: "var foo;",
  59             options: ["never"],
  60             parserOptions: { ecmaVersion: 6 }
  61         },
  62         {
  63             code: "var foo, bar, baz;",
  64             options: ["never"],
  65             parserOptions: { ecmaVersion: 6 }
  66         },
  67         {
  68             code: "function foo() { var foo; var bar; }",
  69             options: ["never"],
  70             parserOptions: { ecmaVersion: 6 }
  71         },
  72         {
  73             code: "let a;",
  74             options: ["never"],
  75             parserOptions: { ecmaVersion: 6 }
  76         },
  77         {
  78             code: "const a = 1;",
  79             options: ["never"],
  80             parserOptions: { ecmaVersion: 6 }
  81         },
  82         {
  83             code: "function foo() { let a, b; if (a) { let c, d; } }",
  84             options: ["never"],
  85             parserOptions: { ecmaVersion: 6 }
  86         },
  87         {
  88             code: "function foo() { const a = 1, b = true; if (a) { const c = 3, d = null; } }",
  89             options: ["never"],
  90             parserOptions: { ecmaVersion: 6 }
  91         },
  92         {
  93             code: "function foo() { let a; const b = false; var c; }",
  94             options: ["never"],
  95             parserOptions: { ecmaVersion: 6 }
  96         },
  97         {
  98             code: "for(var i = 0; i < 1; i++){}",
  99             options: ["never", { ignoreForLoopInit: true }]
 100         },
 101         {
 102             code: "for (var foo in []) {}",
 103             options: ["never", { ignoreForLoopInit: true }]
 104         },
 105         {
 106             code: "for (var foo of []) {}",
 107             options: ["never", { ignoreForLoopInit: true }],
 108             parserOptions: { ecmaVersion: 6 }
 109         }
 110     ],
 111     invalid: [
 112         {
 113             code: "var foo;",
 114             options: ["always"],
 115             errors: [
 116                 {
 117                     messageId: "initialized",
 118                     data: { idName: "foo" },
 119                     type: "VariableDeclarator"
 120                 }
 121             ]
 122         },
 123         {
 124             code: "for (var a in []) var foo;",
 125             options: ["always"],
 126             errors: [
 127                 {
 128                     messageId: "initialized",
 129                     data: { idName: "foo" },
 130                     type: "VariableDeclarator"
 131                 }
 132             ]
 133         },
 134         {
 135             code: "var foo, bar = false, baz;",
 136             options: ["always"],
 137             parserOptions: { ecmaVersion: 6 },
 138             errors: [
 139                 {
 140                     messageId: "initialized",
 141                     data: { idName: "foo" },
 142                     type: "VariableDeclarator"
 143                 },
 144                 {
 145                     messageId: "initialized",
 146                     data: { idName: "baz" },
 147                     type: "VariableDeclarator"
 148                 }
 149             ]
 150         },
 151         {
 152             code: "function foo() { var foo = 0; var bar; }",
 153             options: ["always"],
 154             parserOptions: { ecmaVersion: 6 },
 155             errors: [
 156                 {
 157                     messageId: "initialized",
 158                     data: { idName: "bar" },
 159                     type: "VariableDeclarator"
 160                 }
 161             ]
 162         },
 163         {
 164             code: "function foo() { var foo; var bar = foo; }",
 165             options: ["always"],
 166             parserOptions: { ecmaVersion: 6 },
 167             errors: [
 168                 {
 169                     messageId: "initialized",
 170                     data: { idName: "foo" },
 171                     type: "VariableDeclarator"
 172                 }
 173             ]
 174         },
 175         {
 176             code: "let a;",
 177             options: ["always"],
 178             parserOptions: { ecmaVersion: 6 },
 179             errors: [
 180                 {
 181                     messageId: "initialized",
 182                     data: { idName: "a" },
 183                     type: "VariableDeclarator"
 184                 }
 185             ]
 186         },
 187         {
 188             code: "function foo() { let a = 1, b; if (a) { let c = 3, d = null; } }",
 189             options: ["always"],
 190             parserOptions: { ecmaVersion: 6 },
 191             errors: [
 192                 {
 193                     messageId: "initialized",
 194                     data: { idName: "b" },
 195                     type: "VariableDeclarator"
 196                 }
 197             ]
 198         },
 199         {
 200             code: "function foo() { let a; const b = false; var c; }",
 201             options: ["always"],
 202             parserOptions: { ecmaVersion: 6 },
 203             errors: [
 204                 {
 205                     messageId: "initialized",
 206                     data: { idName: "a" },
 207                     type: "VariableDeclarator"
 208                 },
 209                 {
 210                     messageId: "initialized",
 211                     data: { idName: "c" },
 212                     type: "VariableDeclarator"
 213                 }
 214             ]
 215         },
 216         {
 217             code: "var foo = bar = 2;",
 218             options: ["never"],
 219             parserOptions: { ecmaVersion: 6 },
 220             errors: [
 221                 {
 222                     messageId: "notInitialized",
 223                     data: { idName: "foo" },
 224                     type: "VariableDeclarator"
 225                 }
 226             ]
 227         },
 228         {
 229             code: "var foo = true;",
 230             options: ["never"],
 231             parserOptions: { ecmaVersion: 6 },
 232             errors: [
 233                 {
 234                     messageId: "notInitialized",
 235                     data: { idName: "foo" },
 236                     type: "VariableDeclarator"
 237                 }
 238             ]
 239         },
 240         {
 241             code: "var foo, bar = 5, baz = 3;",
 242             options: ["never"],
 243             parserOptions: { ecmaVersion: 6 },
 244             errors: [
 245                 {
 246                     messageId: "notInitialized",
 247                     data: { idName: "bar" },
 248                     type: "VariableDeclarator"
 249                 },
 250                 {
 251                     messageId: "notInitialized",
 252                     data: { idName: "baz" },
 253                     type: "VariableDeclarator"
 254                 }
 255             ]
 256         },
 257         {
 258             code: "function foo() { var foo; var bar = foo; }",
 259             options: ["never"],
 260             parserOptions: { ecmaVersion: 6 },
 261             errors: [
 262                 {
 263                     messageId: "notInitialized",
 264                     data: { idName: "bar" },
 265
 266                     type: "VariableDeclarator"
 267                 }
 268             ]
 269         },
 270         {
 271             code: "let a = 1;",
 272             options: ["never"],
 273             parserOptions: { ecmaVersion: 6 },
 274             errors: [
 275                 {
 276                     messageId: "notInitialized",
 277                     data: { idName: "a" },
 278                     type: "VariableDeclarator"
 279                 }
 280             ]
 281         },
 282         {
 283             code: "function foo() { let a = 'foo', b; if (a) { let c, d; } }",
 284             options: ["never"],
 285             parserOptions: { ecmaVersion: 6 },
 286             errors: [
 287                 {
 288                     messageId: "notInitialized",
 289                     data: { idName: "a" },
 290                     type: "VariableDeclarator"
 291                 }
 292             ]
 293         },
 294         {
 295             code: "function foo() { let a; const b = false; var c = 1; }",
 296             options: ["never"],
 297             parserOptions: { ecmaVersion: 6 },
 298             errors: [
 299                 {
 300                     messageId: "notInitialized",
 301                     data: { idName: "c" },
 302                     type: "VariableDeclarator"
 303                 }
 304             ]
 305         },
 306         {
 307             code: "for(var i = 0; i < 1; i++){}",
 308             options: ["never"],
 309             errors: [
 310                 {
 311                     messageId: "notInitialized",
 312                     data: { idName: "i" },
 313                     type: "VariableDeclarator"
 314                 }
 315             ]
 316         },
 317         {
 318             code: "for (var foo in []) {}",
 319             options: ["never"],
 320             errors: [
 321                 {
 322                     messageId: "notInitialized",
 323                     data: { idName: "foo" },
 324                     type: "VariableDeclarator"
 325                 }
 326             ]
 327         },
 328         {
 329             code: "for (var foo of []) {}",
 330             options: ["never"],
 331             parserOptions: { ecmaVersion: 6 },
 332             errors: [
 333                 {
 334                     messageId: "notInitialized",
 335                     data: { idName: "foo" },
 336                     type: "VariableDeclarator"
 337                 }
 338             ]
 339         }
 340     ]
 341 });