eslint/tests/lib/rules/no-shadow.js

   1 /**
   2  * @fileoverview Tests for no-shadow rule.
   3  * @author Ilya Volodin
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Requirements
  10 //------------------------------------------------------------------------------
  11
  12 const rule = require("../../../lib/rules/no-shadow"),
  13     { RuleTester } = require("../../../lib/rule-tester");
  14
  15 //------------------------------------------------------------------------------
  16 // Tests
  17 //------------------------------------------------------------------------------
  18
  19 const ruleTester = new RuleTester();
  20
  21 ruleTester.run("no-shadow", rule, {
  22     valid: [
  23         "var a=3; function b(x) { a++; return x + a; }; setTimeout(function() { b(a); }, 0);",
  24         "(function() { var doSomething = function doSomething() {}; doSomething() }())",
  25         "var arguments;\nfunction bar() { }",
  26         { code: "var a=3; var b = (x) => { a++; return x + a; }; setTimeout(() => { b(a); }, 0);", parserOptions: { ecmaVersion: 6 } },
  27         { code: "class A {}", parserOptions: { ecmaVersion: 6 } },
  28         { code: "class A { constructor() { var a; } }", parserOptions: { ecmaVersion: 6 } },
  29         { code: "(function() { var A = class A {}; })()", parserOptions: { ecmaVersion: 6 } },
  30         { code: "{ var a; } var a;", parserOptions: { ecmaVersion: 6 } }, // this case reports `no-redeclare`, not shadowing.
  31         { code: "{ let a; } let a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  32         { code: "{ let a; } var a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  33         { code: "{ let a; } function a() {}", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  34         { code: "{ const a = 0; } const a = 1;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  35         { code: "{ const a = 0; } var a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  36         { code: "{ const a = 0; } function a() {}", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  37         { code: "function foo() { let a; } let a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  38         { code: "function foo() { let a; } var a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  39         { code: "function foo() { let a; } function a() {}", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  40         { code: "function foo() { var a; } let a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  41         { code: "function foo() { var a; } var a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  42         { code: "function foo() { var a; } function a() {}", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  43         { code: "function foo(a) { } let a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  44         { code: "function foo(a) { } var a;", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  45         { code: "function foo(a) { } function a() {}", options: [{ hoist: "never" }], parserOptions: { ecmaVersion: 6 } },
  46         { code: "{ let a; } let a;", parserOptions: { ecmaVersion: 6 } },
  47         { code: "{ let a; } var a;", parserOptions: { ecmaVersion: 6 } },
  48         { code: "{ const a = 0; } const a = 1;", parserOptions: { ecmaVersion: 6 } },
  49         { code: "{ const a = 0; } var a;", parserOptions: { ecmaVersion: 6 } },
  50         { code: "function foo() { let a; } let a;", parserOptions: { ecmaVersion: 6 } },
  51         { code: "function foo() { let a; } var a;", parserOptions: { ecmaVersion: 6 } },
  52         { code: "function foo() { var a; } let a;", parserOptions: { ecmaVersion: 6 } },
  53         { code: "function foo() { var a; } var a;", parserOptions: { ecmaVersion: 6 } },
  54         { code: "function foo(a) { } let a;", parserOptions: { ecmaVersion: 6 } },
  55         { code: "function foo(a) { } var a;", parserOptions: { ecmaVersion: 6 } },
  56         "function foo() { var Object = 0; }",
  57         { code: "function foo() { var top = 0; }", env: { browser: true } },
  58         { code: "var Object = 0;", options: [{ builtinGlobals: true }] },
  59         { code: "var top = 0;", options: [{ builtinGlobals: true }], env: { browser: true } },
  60         { code: "function foo(cb) { (function (cb) { cb(42); })(cb); }", options: [{ allow: ["cb"] }] }
  61     ],
  62     invalid: [
  63         {
  64             code: "function a(x) { var b = function c() { var x = 'foo'; }; }",
  65             errors: [{
  66                 messageId: "noShadow",
  67                 data: {
  68                     name: "x",
  69                     shadowedLine: 1,
  70                     shadowedColumn: 12
  71                 },
  72                 type: "Identifier",
  73                 line: 1,
  74                 column: 44
  75             }]
  76         },
  77         {
  78             code: "var a = (x) => { var b = () => { var x = 'foo'; }; }",
  79             parserOptions: { ecmaVersion: 6 },
  80             errors: [{
  81                 messageId: "noShadow",
  82                 data: {
  83                     name: "x",
  84                     shadowedLine: 1,
  85                     shadowedColumn: 10
  86                 },
  87                 type: "Identifier",
  88                 line: 1,
  89                 column: 38
  90             }]
  91         },
  92         {
  93             code: "function a(x) { var b = function () { var x = 'foo'; }; }",
  94             errors: [{
  95                 messageId: "noShadow",
  96                 data: {
  97                     name: "x",
  98                     shadowedLine: 1,
  99                     shadowedColumn: 12
 100                 },
 101                 type: "Identifier",
 102                 line: 1,
 103                 column: 43
 104             }]
 105         },
 106         {
 107             code: "var x = 1; function a(x) { return ++x; }",
 108             errors: [{
 109                 messageId: "noShadow",
 110                 data: {
 111                     name: "x",
 112                     shadowedLine: 1,
 113                     shadowedColumn: 5
 114                 },
 115                 type: "Identifier",
 116                 line: 1,
 117                 column: 23
 118             }]
 119         },
 120         {
 121             code: "var a=3; function b() { var a=10; }",
 122             errors: [{
 123                 messageId: "noShadow",
 124                 data: {
 125                     name: "a",
 126                     shadowedLine: 1,
 127                     shadowedColumn: 5
 128                 },
 129                 type: "Identifier"
 130             }]
 131         },
 132         {
 133             code: "var a=3; function b() { var a=10; }; setTimeout(function() { b(); }, 0);",
 134             errors: [{
 135                 messageId: "noShadow",
 136                 data: {
 137                     name: "a",
 138                     shadowedLine: 1,
 139                     shadowedColumn: 5
 140                 },
 141                 type: "Identifier"
 142             }]
 143         },
 144         {
 145             code: "var a=3; function b() { var a=10; var b=0; }; setTimeout(function() { b(); }, 0);",
 146             errors: [
 147                 {
 148                     messageId: "noShadow",
 149                     data: {
 150                         name: "a",
 151                         shadowedLine: 1,
 152                         shadowedColumn: 5
 153                     },
 154                     type: "Identifier"
 155                 }, {
 156                     messageId: "noShadow",
 157                     data: {
 158                         name: "b",
 159                         shadowedLine: 1,
 160                         shadowedColumn: 19
 161                     },
 162                     type: "Identifier"
 163                 }
 164             ]
 165         },
 166         {
 167             code: "var x = 1; { let x = 2; }",
 168             parserOptions: { ecmaVersion: 6 },
 169             errors: [{
 170                 messageId: "noShadow",
 171                 data: {
 172                     name: "x",
 173                     shadowedLine: 1,
 174                     shadowedColumn: 5
 175                 },
 176                 type: "Identifier"
 177             }]
 178         },
 179         {
 180             code: "let x = 1; { const x = 2; }",
 181             parserOptions: { ecmaVersion: 6 },
 182             errors: [{
 183                 messageId: "noShadow",
 184                 data: {
 185                     name: "x",
 186                     shadowedLine: 1,
 187                     shadowedColumn: 5
 188                 },
 189                 type: "Identifier"
 190             }]
 191         },
 192         {
 193             code: "{ let a; } function a() {}",
 194             parserOptions: { ecmaVersion: 6 },
 195             errors: [{
 196                 messageId: "noShadow",
 197                 data: {
 198                     name: "a",
 199                     shadowedLine: 1,
 200                     shadowedColumn: 21
 201                 },
 202                 type: "Identifier"
 203             }]
 204         },
 205         {
 206             code: "{ const a = 0; } function a() {}",
 207             parserOptions: { ecmaVersion: 6 },
 208             errors: [{
 209                 messageId: "noShadow",
 210                 data: {
 211                     name: "a",
 212                     shadowedLine: 1,
 213                     shadowedColumn: 27
 214                 },
 215                 type: "Identifier"
 216             }]
 217         },
 218         {
 219             code: "function foo() { let a; } function a() {}",
 220             parserOptions: { ecmaVersion: 6 },
 221             errors: [{
 222                 messageId: "noShadow",
 223                 data: {
 224                     name: "a",
 225                     shadowedLine: 1,
 226                     shadowedColumn: 36
 227                 },
 228                 type: "Identifier"
 229             }]
 230         },
 231         {
 232             code: "function foo() { var a; } function a() {}",
 233             parserOptions: { ecmaVersion: 6 },
 234             errors: [{
 235                 messageId: "noShadow",
 236                 data: {
 237                     name: "a",
 238                     shadowedLine: 1,
 239                     shadowedColumn: 36
 240                 },
 241                 type: "Identifier"
 242             }]
 243         },
 244         {
 245             code: "function foo(a) { } function a() {}",
 246             parserOptions: { ecmaVersion: 6 },
 247             errors: [{
 248                 messageId: "noShadow",
 249                 data: {
 250                     name: "a",
 251                     shadowedLine: 1,
 252                     shadowedColumn: 30
 253                 },
 254                 type: "Identifier"
 255             }]
 256         },
 257         {
 258             code: "{ let a; } let a;",
 259             options: [{ hoist: "all" }],
 260             parserOptions: { ecmaVersion: 6 },
 261             errors: [{
 262                 messageId: "noShadow",
 263                 data: {
 264                     name: "a",
 265                     shadowedLine: 1,
 266                     shadowedColumn: 16
 267                 },
 268                 type: "Identifier"
 269             }]
 270         },
 271         {
 272             code: "{ let a; } var a;",
 273             options: [{ hoist: "all" }],
 274             parserOptions: { ecmaVersion: 6 },
 275             errors: [{
 276                 messageId: "noShadow",
 277                 data: {
 278                     name: "a",
 279                     shadowedLine: 1,
 280                     shadowedColumn: 16
 281                 },
 282                 type: "Identifier"
 283             }]
 284         },
 285         {
 286             code: "{ let a; } function a() {}",
 287             options: [{ hoist: "all" }],
 288             parserOptions: { ecmaVersion: 6 },
 289             errors: [{
 290                 messageId: "noShadow",
 291                 data: {
 292                     name: "a",
 293                     shadowedLine: 1,
 294                     shadowedColumn: 21
 295                 },
 296                 type: "Identifier"
 297             }]
 298         },
 299         {
 300             code: "{ const a = 0; } const a = 1;",
 301             options: [{ hoist: "all" }],
 302             parserOptions: { ecmaVersion: 6 },
 303             errors: [{
 304                 messageId: "noShadow",
 305                 data: {
 306                     name: "a",
 307                     shadowedLine: 1,
 308                     shadowedColumn: 24
 309                 },
 310                 type: "Identifier"
 311             }]
 312         },
 313         {
 314             code: "{ const a = 0; } var a;",
 315             options: [{ hoist: "all" }],
 316             parserOptions: { ecmaVersion: 6 },
 317             errors: [{
 318                 messageId: "noShadow",
 319                 data: {
 320                     name: "a",
 321                     shadowedLine: 1,
 322                     shadowedColumn: 22
 323                 },
 324                 type: "Identifier"
 325             }]
 326         },
 327         {
 328             code: "{ const a = 0; } function a() {}",
 329             options: [{ hoist: "all" }],
 330             parserOptions: { ecmaVersion: 6 },
 331             errors: [{
 332                 messageId: "noShadow",
 333                 data: {
 334                     name: "a",
 335                     shadowedLine: 1,
 336                     shadowedColumn: 27
 337                 },
 338                 type: "Identifier"
 339             }]
 340         },
 341         {
 342             code: "function foo() { let a; } let a;",
 343             options: [{ hoist: "all" }],
 344             parserOptions: { ecmaVersion: 6 },
 345             errors: [{
 346                 messageId: "noShadow",
 347                 data: {
 348                     name: "a",
 349                     shadowedLine: 1,
 350                     shadowedColumn: 31
 351                 },
 352                 type: "Identifier"
 353             }]
 354         },
 355         {
 356             code: "function foo() { let a; } var a;",
 357             options: [{ hoist: "all" }],
 358             parserOptions: { ecmaVersion: 6 },
 359             errors: [{
 360                 messageId: "noShadow",
 361                 data: {
 362                     name: "a",
 363                     shadowedLine: 1,
 364                     shadowedColumn: 31
 365                 },
 366                 type: "Identifier"
 367             }]
 368         },
 369         {
 370             code: "function foo() { let a; } function a() {}",
 371             options: [{ hoist: "all" }],
 372             parserOptions: { ecmaVersion: 6 },
 373             errors: [{
 374                 messageId: "noShadow",
 375                 data: {
 376                     name: "a",
 377                     shadowedLine: 1,
 378                     shadowedColumn: 36
 379                 },
 380                 type: "Identifier"
 381             }]
 382         },
 383         {
 384             code: "function foo() { var a; } let a;",
 385             options: [{ hoist: "all" }],
 386             parserOptions: { ecmaVersion: 6 },
 387             errors: [{
 388                 messageId: "noShadow",
 389                 data: {
 390                     name: "a",
 391                     shadowedLine: 1,
 392                     shadowedColumn: 31
 393                 },
 394                 type: "Identifier"
 395             }]
 396         },
 397         {
 398             code: "function foo() { var a; } var a;",
 399             options: [{ hoist: "all" }],
 400             parserOptions: { ecmaVersion: 6 },
 401             errors: [{
 402                 messageId: "noShadow",
 403                 data: {
 404                     name: "a",
 405                     shadowedLine: 1,
 406                     shadowedColumn: 31
 407                 },
 408                 type: "Identifier"
 409             }]
 410         },
 411         {
 412             code: "function foo() { var a; } function a() {}",
 413             options: [{ hoist: "all" }],
 414             parserOptions: { ecmaVersion: 6 },
 415             errors: [{
 416                 messageId: "noShadow",
 417                 data: {
 418                     name: "a",
 419                     shadowedLine: 1,
 420                     shadowedColumn: 36
 421                 },
 422                 type: "Identifier"
 423             }]
 424         },
 425         {
 426             code: "function foo(a) { } let a;",
 427             options: [{ hoist: "all" }],
 428             parserOptions: { ecmaVersion: 6 },
 429             errors: [{
 430                 messageId: "noShadow",
 431                 data: {
 432                     name: "a",
 433                     shadowedLine: 1,
 434                     shadowedColumn: 25
 435                 },
 436                 type: "Identifier"
 437             }]
 438         },
 439         {
 440             code: "function foo(a) { } var a;",
 441             options: [{ hoist: "all" }],
 442             parserOptions: { ecmaVersion: 6 },
 443             errors: [{
 444                 messageId: "noShadow",
 445                 data: {
 446                     name: "a",
 447                     shadowedLine: 1,
 448                     shadowedColumn: 25
 449                 },
 450                 type: "Identifier"
 451             }]
 452         },
 453         {
 454             code: "function foo(a) { } function a() {}",
 455             options: [{ hoist: "all" }],
 456             parserOptions: { ecmaVersion: 6 },
 457             errors: [{
 458                 messageId: "noShadow",
 459                 data: {
 460                     name: "a",
 461                     shadowedLine: 1,
 462                     shadowedColumn: 30
 463                 },
 464                 type: "Identifier"
 465             }]
 466         },
 467         {
 468             code: "(function a() { function a(){} })()",
 469             errors: [{
 470                 messageId: "noShadow",
 471                 data: {
 472                     name: "a",
 473                     shadowedLine: 1,
 474                     shadowedColumn: 11
 475                 },
 476                 type: "Identifier"
 477             }]
 478         },
 479         {
 480             code: "(function a() { class a{} })()",
 481             parserOptions: { ecmaVersion: 6 },
 482             errors: [{
 483                 messageId: "noShadow",
 484                 data: {
 485                     name: "a",
 486                     shadowedLine: 1,
 487                     shadowedColumn: 11
 488                 },
 489                 type: "Identifier"
 490             }]
 491         },
 492         {
 493             code: "(function a() { (function a(){}); })()",
 494             errors: [{
 495                 messageId: "noShadow",
 496                 data: {
 497                     name: "a",
 498                     shadowedLine: 1,
 499                     shadowedColumn: 11
 500                 },
 501                 type: "Identifier"
 502             }]
 503         },
 504         {
 505             code: "(function a() { (class a{}); })()",
 506             parserOptions: { ecmaVersion: 6 },
 507             errors: [{
 508                 messageId: "noShadow",
 509                 data: {
 510                     name: "a",
 511                     shadowedLine: 1,
 512                     shadowedColumn: 11
 513                 },
 514                 type: "Identifier"
 515             }]
 516         },
 517         {
 518             code: "(function() { var a = function(a) {}; })()",
 519             errors: [{
 520                 messageId: "noShadow",
 521                 data: {
 522                     name: "a",
 523                     shadowedLine: 1,
 524                     shadowedColumn: 19
 525                 },
 526                 type: "Identifier"
 527             }]
 528         },
 529         {
 530             code: "(function() { var a = function() { function a() {} }; })()",
 531             errors: [{
 532                 messageId: "noShadow",
 533                 data: {
 534                     name: "a",
 535                     shadowedLine: 1,
 536                     shadowedColumn: 19
 537                 },
 538                 type: "Identifier"
 539             }]
 540         },
 541         {
 542             code: "(function() { var a = function() { class a{} }; })()",
 543             parserOptions: { ecmaVersion: 6 },
 544             errors: [{
 545                 messageId: "noShadow",
 546                 data: {
 547                     name: "a",
 548                     shadowedLine: 1,
 549                     shadowedColumn: 19
 550                 },
 551                 type: "Identifier"
 552             }]
 553         },
 554         {
 555             code: "(function() { var a = function() { (function a() {}); }; })()",
 556             errors: [{
 557                 messageId: "noShadow",
 558                 data: {
 559                     name: "a",
 560                     shadowedLine: 1,
 561                     shadowedColumn: 19
 562                 },
 563                 type: "Identifier"
 564             }]
 565         },
 566         {
 567             code: "(function() { var a = function() { (class a{}); }; })()",
 568             parserOptions: { ecmaVersion: 6 },
 569             errors: [{
 570                 messageId: "noShadow",
 571                 data: {
 572                     name: "a",
 573                     shadowedLine: 1,
 574                     shadowedColumn: 19
 575                 },
 576                 type: "Identifier"
 577             }]
 578         },
 579         {
 580             code: "(function() { var a = class { constructor() { class a {} } }; })()",
 581             parserOptions: { ecmaVersion: 6 },
 582             errors: [{
 583                 messageId: "noShadow",
 584                 data: {
 585                     name: "a",
 586                     shadowedLine: 1,
 587                     shadowedColumn: 19
 588                 },
 589                 type: "Identifier"
 590             }]
 591         },
 592         {
 593             code: "class A { constructor() { var A; } }",
 594             parserOptions: { ecmaVersion: 6 },
 595             errors: [{
 596                 messageId: "noShadow",
 597                 data: {
 598                     name: "A",
 599                     shadowedLine: 1,
 600                     shadowedColumn: 7
 601                 },
 602                 type: "Identifier"
 603             }]
 604         },
 605         {
 606             code: "(function a() { function a(){ function a(){} } })()",
 607             errors: [
 608                 {
 609                     messageId: "noShadow",
 610                     data: {
 611                         name: "a",
 612                         shadowedLine: 1,
 613                         shadowedColumn: 11
 614                     },
 615                     type: "Identifier",
 616                     line: 1,
 617                     column: 26
 618                 },
 619                 {
 620                     messageId: "noShadow",
 621                     data: {
 622                         name: "a",
 623                         shadowedLine: 1,
 624                         shadowedColumn: 26
 625                     },
 626                     type: "Identifier",
 627                     line: 1,
 628                     column: 40
 629                 }
 630             ]
 631         },
 632         {
 633             code: "function foo() { var Object = 0; }",
 634             options: [{ builtinGlobals: true }],
 635             errors: [{
 636                 messageId: "noShadowGlobal",
 637                 data: {
 638                     name: "Object"
 639                 },
 640                 type: "Identifier"
 641             }]
 642         },
 643         {
 644             code: "function foo() { var top = 0; }",
 645             options: [{ builtinGlobals: true }],
 646             env: { browser: true },
 647             errors: [{
 648                 messageId: "noShadowGlobal",
 649                 data: {
 650                     name: "top"
 651                 },
 652                 type: "Identifier"
 653             }]
 654         },
 655         {
 656             code: "var Object = 0;",
 657             options: [{ builtinGlobals: true }],
 658             parserOptions: { ecmaVersion: 6, sourceType: "module" },
 659             errors: [{
 660                 messageId: "noShadowGlobal",
 661                 data: {
 662                     name: "Object"
 663                 },
 664                 type: "Identifier"
 665             }]
 666         },
 667         {
 668             code: "var top = 0;",
 669             options: [{ builtinGlobals: true }],
 670             parserOptions: { ecmaVersion: 6, sourceType: "module" },
 671             env: { browser: true },
 672             errors: [{
 673                 messageId: "noShadowGlobal",
 674                 data: {
 675                     name: "top"
 676                 },
 677                 type: "Identifier"
 678             }]
 679         },
 680         {
 681             code: "var Object = 0;",
 682             options: [{ builtinGlobals: true }],
 683             parserOptions: { ecmaFeatures: { globalReturn: true } },
 684             errors: [{
 685                 messageId: "noShadowGlobal",
 686                 data: {
 687                     name: "Object"
 688                 },
 689                 type: "Identifier"
 690             }]
 691         },
 692         {
 693             code: "var top = 0;",
 694             options: [{ builtinGlobals: true }],
 695             parserOptions: { ecmaFeatures: { globalReturn: true } },
 696             env: { browser: true },
 697             errors: [{
 698                 messageId: "noShadowGlobal",
 699                 data: {
 700                     name: "top"
 701                 },
 702                 type: "Identifier"
 703             }]
 704         },
 705         {
 706             code: "function foo(cb) { (function (cb) { cb(42); })(cb); }",
 707             errors: [{
 708                 messageId: "noShadow",
 709                 data: {
 710                     name: "cb",
 711                     shadowedLine: 1,
 712                     shadowedColumn: 14
 713                 },
 714                 type: "Identifier",
 715                 line: 1,
 716                 column: 31
 717             }]
 718         }
 719     ]
 720 });