eslint/tests/lib/rules/prefer-destructuring.js

   1 /**
   2  * @fileoverview Prefer destructuring from arrays and objects
   3  * @author Alex LaFroscia
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Requirements
   9 //------------------------------------------------------------------------------
  10
  11 const rule = require("../../../lib/rules/prefer-destructuring"),
  12     { RuleTester } = require("../../../lib/rule-tester");
  13
  14
  15 //------------------------------------------------------------------------------
  16 // Tests
  17 //------------------------------------------------------------------------------
  18
  19 const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 2020 } });
  20
  21 ruleTester.run("prefer-destructuring", rule, {
  22     valid: [
  23         "var [foo] = array;",
  24         "var { foo } = object;",
  25         "var foo;",
  26         {
  27
  28             // Ensure that the default behavior does not require destructuring when renaming
  29             code: "var foo = object.bar;",
  30             options: [{ VariableDeclarator: { object: true } }]
  31         },
  32         {
  33
  34             // Ensure that the default behavior does not require destructuring when renaming
  35             code: "var foo = object.bar;",
  36             options: [{ object: true }]
  37         },
  38         {
  39             code: "var foo = object.bar;",
  40             options: [{ VariableDeclarator: { object: true } }, { enforceForRenamedProperties: false }]
  41         },
  42         {
  43             code: "var foo = object.bar;",
  44             options: [{ object: true }, { enforceForRenamedProperties: false }]
  45         },
  46         {
  47             code: "var foo = object['bar'];",
  48             options: [{ VariableDeclarator: { object: true } }, { enforceForRenamedProperties: false }]
  49         },
  50         {
  51             code: "var foo = object[bar];",
  52             options: [{ object: true }, { enforceForRenamedProperties: false }]
  53         },
  54         {
  55             code: "var { bar: foo } = object;",
  56             options: [{ VariableDeclarator: { object: true } }, { enforceForRenamedProperties: true }]
  57         },
  58         {
  59             code: "var { bar: foo } = object;",
  60             options: [{ object: true }, { enforceForRenamedProperties: true }]
  61         },
  62         {
  63             code: "var { [bar]: foo } = object;",
  64             options: [{ VariableDeclarator: { object: true } }, { enforceForRenamedProperties: true }]
  65         },
  66         {
  67             code: "var { [bar]: foo } = object;",
  68             options: [{ object: true }, { enforceForRenamedProperties: true }]
  69         },
  70         {
  71             code: "var foo = array[0];",
  72             options: [{ VariableDeclarator: { array: false } }]
  73         },
  74         {
  75             code: "var foo = array[0];",
  76             options: [{ array: false }]
  77         },
  78         {
  79             code: "var foo = object.foo;",
  80             options: [{ VariableDeclarator: { object: false } }]
  81         },
  82         {
  83             code: "var foo = object['foo'];",
  84             options: [{ VariableDeclarator: { object: false } }]
  85         },
  86         "({ foo } = object);",
  87         {
  88
  89             // Fix #8654
  90             code: "var foo = array[0];",
  91             options: [{ VariableDeclarator: { array: false } }, { enforceForRenamedProperties: true }]
  92         },
  93         {
  94
  95             // Fix #8654
  96             code: "var foo = array[0];",
  97             options: [{ array: false }, { enforceForRenamedProperties: true }]
  98         },
  99         "[foo] = array;",
 100         "foo += array[0]",
 101         {
 102             code: "foo &&= array[0]",
 103             parserOptions: { ecmaVersion: 2021 }
 104         },
 105         "foo += bar.foo",
 106         {
 107             code: "foo ||= bar.foo",
 108             parserOptions: { ecmaVersion: 2021 }
 109         },
 110         {
 111             code: "foo ??= bar['foo']",
 112             parserOptions: { ecmaVersion: 2021 }
 113         },
 114         {
 115             code: "foo = object.foo;",
 116             options: [{ AssignmentExpression: { object: false } }, { enforceForRenamedProperties: true }]
 117         },
 118         {
 119             code: "foo = object.foo;",
 120             options: [{ AssignmentExpression: { object: false } }, { enforceForRenamedProperties: false }]
 121         },
 122         {
 123             code: "foo = array[0];",
 124             options: [{ AssignmentExpression: { array: false } }, { enforceForRenamedProperties: true }]
 125         },
 126         {
 127             code: "foo = array[0];",
 128             options: [{ AssignmentExpression: { array: false } }, { enforceForRenamedProperties: false }]
 129         },
 130         {
 131             code: "foo = array[0];",
 132             options: [{ VariableDeclarator: { array: true }, AssignmentExpression: { array: false } }, { enforceForRenamedProperties: false }]
 133         },
 134         {
 135             code: "var foo = array[0];",
 136             options: [{ VariableDeclarator: { array: false }, AssignmentExpression: { array: true } }, { enforceForRenamedProperties: false }]
 137         },
 138         {
 139             code: "foo = object.foo;",
 140             options: [{ VariableDeclarator: { object: true }, AssignmentExpression: { object: false } }]
 141         },
 142         {
 143             code: "var foo = object.foo;",
 144             options: [{ VariableDeclarator: { object: false }, AssignmentExpression: { object: true } }]
 145         },
 146         "class Foo extends Bar { static foo() {var foo = super.foo} }",
 147         "foo = bar[foo];",
 148         "var foo = bar[foo];",
 149         {
 150             code: "var {foo: {bar}} = object;",
 151             options: [{ object: true }]
 152         },
 153         {
 154             code: "var {bar} = object.foo;",
 155             options: [{ object: true }]
 156         },
 157
 158         // Optional chaining
 159         "var foo = array?.[0];", // because the fixed code can throw TypeError.
 160         "var foo = object?.foo;"
 161     ],
 162
 163     invalid: [
 164         {
 165             code: "var foo = array[0];",
 166             output: null,
 167             errors: [{
 168                 messageId: "preferDestructuring",
 169                 data: { type: "array" },
 170                 type: "VariableDeclarator"
 171             }]
 172         },
 173         {
 174             code: "foo = array[0];",
 175             output: null,
 176             errors: [{
 177                 messageId: "preferDestructuring",
 178                 data: { type: "array" },
 179                 type: "AssignmentExpression"
 180             }]
 181         },
 182         {
 183             code: "var foo = object.foo;",
 184             output: "var {foo} = object;",
 185             errors: [{
 186                 messageId: "preferDestructuring",
 187                 data: { type: "object" },
 188                 type: "VariableDeclarator"
 189             }]
 190         },
 191         {
 192             code: "var foo = (a, b).foo;",
 193             output: "var {foo} = (a, b);",
 194             errors: [{
 195                 messageId: "preferDestructuring",
 196                 data: { type: "object" },
 197                 type: "VariableDeclarator"
 198             }]
 199         },
 200         {
 201             code: "var length = (() => {}).length;",
 202             output: "var {length} = () => {};",
 203             errors: [{
 204                 messageId: "preferDestructuring",
 205                 data: { type: "object" },
 206                 type: "VariableDeclarator"
 207             }]
 208         },
 209         {
 210             code: "var foo = (a = b).foo;",
 211             output: "var {foo} = a = b;",
 212             errors: [{
 213                 messageId: "preferDestructuring",
 214                 data: { type: "object" },
 215                 type: "VariableDeclarator"
 216             }]
 217         },
 218         {
 219             code: "var foo = (a || b).foo;",
 220             output: "var {foo} = a || b;",
 221             errors: [{
 222                 messageId: "preferDestructuring",
 223                 data: { type: "object" },
 224                 type: "VariableDeclarator"
 225             }]
 226         },
 227         {
 228             code: "var foo = (f()).foo;",
 229             output: "var {foo} = f();",
 230             errors: [{
 231                 messageId: "preferDestructuring",
 232                 data: { type: "object" },
 233                 type: "VariableDeclarator"
 234             }]
 235         },
 236         {
 237             code: "var foo = object.bar.foo;",
 238             output: "var {foo} = object.bar;",
 239             errors: [{
 240                 messageId: "preferDestructuring",
 241                 data: { type: "object" },
 242                 type: "VariableDeclarator"
 243             }]
 244         },
 245         {
 246             code: "var foobar = object.bar;",
 247             output: null,
 248             options: [{ VariableDeclarator: { object: true } }, { enforceForRenamedProperties: true }],
 249             errors: [{
 250                 messageId: "preferDestructuring",
 251                 data: { type: "object" },
 252                 type: "VariableDeclarator"
 253             }]
 254         },
 255         {
 256             code: "var foobar = object.bar;",
 257             output: null,
 258             options: [{ object: true }, { enforceForRenamedProperties: true }],
 259             errors: [{
 260                 messageId: "preferDestructuring",
 261                 data: { type: "object" },
 262                 type: "VariableDeclarator"
 263             }]
 264         },
 265         {
 266             code: "var foo = object[bar];",
 267             output: null,
 268             options: [{ VariableDeclarator: { object: true } }, { enforceForRenamedProperties: true }],
 269             errors: [{
 270                 messageId: "preferDestructuring",
 271                 data: { type: "object" },
 272                 type: "VariableDeclarator"
 273             }]
 274         },
 275         {
 276             code: "var foo = object[bar];",
 277             output: null,
 278             options: [{ object: true }, { enforceForRenamedProperties: true }],
 279             errors: [{
 280                 messageId: "preferDestructuring",
 281                 data: { type: "object" },
 282                 type: "VariableDeclarator"
 283             }]
 284         },
 285         {
 286             code: "var foo = object[foo];",
 287             output: null,
 288             options: [{ object: true }, { enforceForRenamedProperties: true }],
 289             errors: [{
 290                 messageId: "preferDestructuring",
 291                 data: { type: "object" },
 292                 type: "VariableDeclarator"
 293             }]
 294         },
 295         {
 296             code: "var foo = object['foo'];",
 297             output: null,
 298             errors: [{
 299                 messageId: "preferDestructuring",
 300                 data: { type: "object" },
 301                 type: "VariableDeclarator"
 302             }]
 303         },
 304         {
 305             code: "foo = object.foo;",
 306             output: null,
 307             errors: [{
 308                 messageId: "preferDestructuring",
 309                 data: { type: "object" },
 310                 type: "AssignmentExpression"
 311             }]
 312         },
 313         {
 314             code: "foo = object['foo'];",
 315             output: null,
 316             errors: [{
 317                 messageId: "preferDestructuring",
 318                 data: { type: "object" },
 319                 type: "AssignmentExpression"
 320             }]
 321         },
 322         {
 323             code: "var foo = array[0];",
 324             output: null,
 325             options: [{ VariableDeclarator: { array: true } }, { enforceForRenamedProperties: true }],
 326             errors: [{
 327                 messageId: "preferDestructuring",
 328                 data: { type: "array" },
 329                 type: "VariableDeclarator"
 330             }]
 331         },
 332         {
 333             code: "foo = array[0];",
 334             output: null,
 335             options: [{ AssignmentExpression: { array: true } }],
 336             errors: [{
 337                 messageId: "preferDestructuring",
 338                 data: { type: "array" },
 339                 type: "AssignmentExpression"
 340             }]
 341         },
 342         {
 343             code: "var foo = array[0];",
 344             output: null,
 345             options: [
 346                 {
 347                     VariableDeclarator: { array: true },
 348                     AssignmentExpression: { array: false }
 349                 },
 350                 { enforceForRenamedProperties: true }
 351             ],
 352             errors: [{
 353                 messageId: "preferDestructuring",
 354                 data: { type: "array" },
 355                 type: "VariableDeclarator"
 356             }]
 357         },
 358         {
 359             code: "var foo = array[0];",
 360             output: null,
 361             options: [
 362                 {
 363                     VariableDeclarator: { array: true },
 364                     AssignmentExpression: { array: false }
 365                 }
 366             ],
 367             errors: [{
 368                 messageId: "preferDestructuring",
 369                 data: { type: "array" },
 370                 type: "VariableDeclarator"
 371             }]
 372         },
 373         {
 374             code: "foo = array[0];",
 375             output: null,
 376             options: [
 377                 {
 378                     VariableDeclarator: { array: false },
 379                     AssignmentExpression: { array: true }
 380                 }
 381             ],
 382             errors: [{
 383                 messageId: "preferDestructuring",
 384                 data: { type: "array" },
 385                 type: "AssignmentExpression"
 386             }]
 387         },
 388         {
 389             code: "foo = object.foo;",
 390             output: null,
 391             options: [
 392                 {
 393                     VariableDeclarator: { array: true, object: false },
 394                     AssignmentExpression: { object: true }
 395                 }
 396             ],
 397             errors: [{
 398                 messageId: "preferDestructuring",
 399                 data: { type: "object" },
 400                 type: "AssignmentExpression"
 401             }]
 402         },
 403         {
 404             code: "class Foo extends Bar { static foo() {var bar = super.foo.bar} }",
 405             output: "class Foo extends Bar { static foo() {var {bar} = super.foo} }",
 406             errors: [{
 407                 messageId: "preferDestructuring",
 408                 data: { type: "object" },
 409                 type: "VariableDeclarator"
 410             }]
 411         },
 412
 413         // comments
 414         {
 415             code: "var /* comment */ foo = object.foo;",
 416             output: "var /* comment */ {foo} = object;",
 417             errors: [{
 418                 messageId: "preferDestructuring",
 419                 data: { type: "object" },
 420                 type: "VariableDeclarator"
 421             }]
 422         },
 423         {
 424             code: "var a, /* comment */foo = object.foo;",
 425             output: "var a, /* comment */{foo} = object;",
 426             errors: [{
 427                 messageId: "preferDestructuring",
 428                 data: { type: "object" },
 429                 type: "VariableDeclarator"
 430             }]
 431         },
 432         {
 433             code: "var foo /* comment */ = object.foo;",
 434             output: null,
 435             errors: [{
 436                 messageId: "preferDestructuring",
 437                 data: { type: "object" },
 438                 type: "VariableDeclarator"
 439             }]
 440         },
 441         {
 442             code: "var a, foo /* comment */ = object.foo;",
 443             output: null,
 444             errors: [{
 445                 messageId: "preferDestructuring",
 446                 data: { type: "object" },
 447                 type: "VariableDeclarator"
 448             }]
 449         },
 450         {
 451             code: "var foo /* comment */ = object.foo, a;",
 452             output: null,
 453             errors: [{
 454                 messageId: "preferDestructuring",
 455                 data: { type: "object" },
 456                 type: "VariableDeclarator"
 457             }]
 458         },
 459         {
 460             code: "var foo // comment\n = object.foo;",
 461             output: null,
 462             errors: [{
 463                 messageId: "preferDestructuring",
 464                 data: { type: "object" },
 465                 type: "VariableDeclarator"
 466             }]
 467         },
 468         {
 469             code: "var foo = /* comment */ object.foo;",
 470             output: null,
 471             errors: [{
 472                 messageId: "preferDestructuring",
 473                 data: { type: "object" },
 474                 type: "VariableDeclarator"
 475             }]
 476         },
 477         {
 478             code: "var foo = // comment\n object.foo;",
 479             output: null,
 480             errors: [{
 481                 messageId: "preferDestructuring",
 482                 data: { type: "object" },
 483                 type: "VariableDeclarator"
 484             }]
 485         },
 486         {
 487             code: "var foo = (/* comment */ object).foo;",
 488             output: null,
 489             errors: [{
 490                 messageId: "preferDestructuring",
 491                 data: { type: "object" },
 492                 type: "VariableDeclarator"
 493             }]
 494         },
 495         {
 496             code: "var foo = (object /* comment */).foo;",
 497             output: null,
 498             errors: [{
 499                 messageId: "preferDestructuring",
 500                 data: { type: "object" },
 501                 type: "VariableDeclarator"
 502             }]
 503         },
 504         {
 505             code: "var foo = bar(/* comment */).foo;",
 506             output: "var {foo} = bar(/* comment */);",
 507             errors: [{
 508                 messageId: "preferDestructuring",
 509                 data: { type: "object" },
 510                 type: "VariableDeclarator"
 511             }]
 512         },
 513         {
 514             code: "var foo = bar/* comment */.baz.foo;",
 515             output: "var {foo} = bar/* comment */.baz;",
 516             errors: [{
 517                 messageId: "preferDestructuring",
 518                 data: { type: "object" },
 519                 type: "VariableDeclarator"
 520             }]
 521         },
 522         {
 523             code: "var foo = bar[// comment\nbaz].foo;",
 524             output: "var {foo} = bar[// comment\nbaz];",
 525             errors: [{
 526                 messageId: "preferDestructuring",
 527                 data: { type: "object" },
 528                 type: "VariableDeclarator"
 529             }]
 530         },
 531         {
 532             code: "var foo // comment\n = bar(/* comment */).foo;",
 533             output: null,
 534             errors: [{
 535                 messageId: "preferDestructuring",
 536                 data: { type: "object" },
 537                 type: "VariableDeclarator"
 538             }]
 539         },
 540         {
 541             code: "var foo = bar/* comment */.baz/* comment */.foo;",
 542             output: null,
 543             errors: [{
 544                 messageId: "preferDestructuring",
 545                 data: { type: "object" },
 546                 type: "VariableDeclarator"
 547             }]
 548         },
 549         {
 550             code: "var foo = object// comment\n.foo;",
 551             output: null,
 552             errors: [{
 553                 messageId: "preferDestructuring",
 554                 data: { type: "object" },
 555                 type: "VariableDeclarator"
 556             }]
 557         },
 558         {
 559             code: "var foo = object./* comment */foo;",
 560             output: null,
 561             errors: [{
 562                 messageId: "preferDestructuring",
 563                 data: { type: "object" },
 564                 type: "VariableDeclarator"
 565             }]
 566         },
 567         {
 568             code: "var foo = (/* comment */ object.foo);",
 569             output: null,
 570             errors: [{
 571                 messageId: "preferDestructuring",
 572                 data: { type: "object" },
 573                 type: "VariableDeclarator"
 574             }]
 575         },
 576         {
 577             code: "var foo = (object.foo /* comment */);",
 578             output: null,
 579             errors: [{
 580                 messageId: "preferDestructuring",
 581                 data: { type: "object" },
 582                 type: "VariableDeclarator"
 583             }]
 584         },
 585         {
 586             code: "var foo = object.foo/* comment */;",
 587             output: "var {foo} = object/* comment */;",
 588             errors: [{
 589                 messageId: "preferDestructuring",
 590                 data: { type: "object" },
 591                 type: "VariableDeclarator"
 592             }]
 593         },
 594         {
 595             code: "var foo = object.foo// comment",
 596             output: "var {foo} = object// comment",
 597             errors: [{
 598                 messageId: "preferDestructuring",
 599                 data: { type: "object" },
 600                 type: "VariableDeclarator"
 601             }]
 602         },
 603         {
 604             code: "var foo = object.foo/* comment */, a;",
 605             output: "var {foo} = object/* comment */, a;",
 606             errors: [{
 607                 messageId: "preferDestructuring",
 608                 data: { type: "object" },
 609                 type: "VariableDeclarator"
 610             }]
 611         },
 612         {
 613             code: "var foo = object.foo// comment\n, a;",
 614             output: "var {foo} = object// comment\n, a;",
 615             errors: [{
 616                 messageId: "preferDestructuring",
 617                 data: { type: "object" },
 618                 type: "VariableDeclarator"
 619             }]
 620         },
 621         {
 622             code: "var foo = object.foo, /* comment */ a;",
 623             output: "var {foo} = object, /* comment */ a;",
 624             errors: [{
 625                 messageId: "preferDestructuring",
 626                 data: { type: "object" },
 627                 type: "VariableDeclarator"
 628             }]
 629         }
 630     ]
 631 });