| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @emails react-core |
| 8 | */ |
| 9 | |
| 10 | 'use strict'; |
| 11 | |
| 12 | describe('ReactChildren', () => { |
| 13 | let React; |
| 14 | let ReactDOMClient; |
| 15 | let act; |
| 16 | let assertConsoleErrorDev; |
| 17 | |
| 18 | beforeEach(() => { |
| 19 | jest.resetModules(); |
| 20 | React = require('react'); |
| 21 | ReactDOMClient = require('react-dom/client'); |
| 22 | ({act, assertConsoleErrorDev} = require('internal-test-utils')); |
| 23 | }); |
| 24 | |
| 25 | it('should support identity for simple', () => { |
| 26 | const context = {}; |
| 27 | const callback = jest.fn().mockImplementation(function (kid, index) { |
| 28 | expect(this).toBe(context); |
| 29 | return kid; |
| 30 | }); |
| 31 | |
| 32 | const simpleKid = <span key="simple" />; |
| 33 | |
| 34 | // First pass children into a component to fully simulate what happens when |
| 35 | // using structures that arrive from transforms. |
| 36 | |
| 37 | const instance = <div>{simpleKid}</div>; |
| 38 | React.Children.forEach(instance.props.children, callback, context); |
| 39 | expect(callback).toHaveBeenCalledWith(simpleKid, 0); |
| 40 | callback.mockClear(); |
| 41 | const mappedChildren = React.Children.map( |
| 42 | instance.props.children, |
| 43 | callback, |
| 44 | context, |
| 45 | ); |
| 46 | expect(callback).toHaveBeenCalledWith(simpleKid, 0); |
| 47 | expect(mappedChildren[0]).toEqual(<span key=".$simple" />); |
| 48 | }); |
| 49 | |
| 50 | it('should support Portal components', () => { |
| 51 | const context = {}; |
| 52 | const callback = jest.fn().mockImplementation(function (kid, index) { |
| 53 | expect(this).toBe(context); |
| 54 | return kid; |
| 55 | }); |
| 56 | const ReactDOM = require('react-dom'); |
| 57 | const portalContainer = document.createElement('div'); |
| 58 | |
| 59 | const simpleChild = <span key="simple" />; |
| 60 | const reactPortal = ReactDOM.createPortal(simpleChild, portalContainer); |
| 61 | |
| 62 | const parentInstance = <div>{reactPortal}</div>; |
| 63 | React.Children.forEach(parentInstance.props.children, callback, context); |
| 64 | expect(callback).toHaveBeenCalledWith(reactPortal, 0); |
| 65 | callback.mockClear(); |
| 66 | const mappedChildren = React.Children.map( |
| 67 | parentInstance.props.children, |
| 68 | callback, |
| 69 | context, |
| 70 | ); |
| 71 | expect(callback).toHaveBeenCalledWith(reactPortal, 0); |
| 72 | expect(mappedChildren[0]).toEqual(reactPortal); |
| 73 | }); |
| 74 | |
| 75 | it('should treat single arrayless child as being in array', () => { |
| 76 | const context = {}; |
| 77 | const callback = jest.fn().mockImplementation(function (kid, index) { |
| 78 | expect(this).toBe(context); |
| 79 | return kid; |
| 80 | }); |
| 81 | |
| 82 | const simpleKid = <span />; |
| 83 | const instance = <div>{simpleKid}</div>; |
| 84 | React.Children.forEach(instance.props.children, callback, context); |
| 85 | expect(callback).toHaveBeenCalledWith(simpleKid, 0); |
| 86 | callback.mockClear(); |
| 87 | const mappedChildren = React.Children.map( |
| 88 | instance.props.children, |
| 89 | callback, |
| 90 | context, |
| 91 | ); |
| 92 | expect(callback).toHaveBeenCalledWith(simpleKid, 0); |
| 93 | expect(mappedChildren[0]).toEqual(<span key=".0" />); |
| 94 | }); |
| 95 | |
| 96 | it('should treat single child in array as expected', () => { |
| 97 | const context = {}; |
| 98 | const callback = jest.fn().mockImplementation(function (kid, index) { |
| 99 | expect(this).toBe(context); |
| 100 | return kid; |
| 101 | }); |
| 102 | |
| 103 | const simpleKid = <span key="simple" />; |
| 104 | const instance = <div>{[simpleKid]}</div>; |
| 105 | React.Children.forEach(instance.props.children, callback, context); |
| 106 | expect(callback).toHaveBeenCalledWith(simpleKid, 0); |
| 107 | callback.mockClear(); |
| 108 | const mappedChildren = React.Children.map( |
| 109 | instance.props.children, |
| 110 | callback, |
| 111 | context, |
| 112 | ); |
| 113 | expect(callback).toHaveBeenCalledWith(simpleKid, 0); |
| 114 | expect(mappedChildren[0]).toEqual(<span key=".$simple" />); |
| 115 | }); |
| 116 | |
| 117 | it('should be called for each child', () => { |
| 118 | const zero = <div key="keyZero" />; |
| 119 | const one = null; |
| 120 | const two = <div key="keyTwo" />; |
| 121 | const three = null; |
| 122 | const four = <div key="keyFour" />; |
| 123 | const context = {}; |
| 124 | |
| 125 | const callback = jest.fn().mockImplementation(function (kid) { |
| 126 | expect(this).toBe(context); |
| 127 | return kid; |
| 128 | }); |
| 129 | |
| 130 | const instance = ( |
| 131 | <div> |
| 132 | {zero} |
| 133 | {one} |
| 134 | {two} |
| 135 | {three} |
| 136 | {four} |
| 137 | </div> |
| 138 | ); |
| 139 | |
| 140 | function assertCalls() { |
| 141 | expect(callback).toHaveBeenCalledWith(zero, 0); |
| 142 | expect(callback).toHaveBeenCalledWith(one, 1); |
| 143 | expect(callback).toHaveBeenCalledWith(two, 2); |
| 144 | expect(callback).toHaveBeenCalledWith(three, 3); |
| 145 | expect(callback).toHaveBeenCalledWith(four, 4); |
| 146 | callback.mockClear(); |
| 147 | } |
| 148 | |
| 149 | React.Children.forEach(instance.props.children, callback, context); |
| 150 | assertCalls(); |
| 151 | |
| 152 | const mappedChildren = React.Children.map( |
| 153 | instance.props.children, |
| 154 | callback, |
| 155 | context, |
| 156 | ); |
| 157 | assertCalls(); |
| 158 | expect(mappedChildren).toEqual([ |
| 159 | <div key=".$keyZero" />, |
| 160 | <div key=".$keyTwo" />, |
| 161 | <div key=".$keyFour" />, |
| 162 | ]); |
| 163 | }); |
| 164 | |
| 165 | it('should traverse children of different kinds', () => { |
| 166 | const div = <div key="divNode" />; |
| 167 | const span = <span key="spanNode" />; |
| 168 | const a = <a key="aNode" />; |
| 169 | |
| 170 | const context = {}; |
| 171 | const callback = jest.fn().mockImplementation(function (kid) { |
| 172 | expect(this).toBe(context); |
| 173 | return kid; |
| 174 | }); |
| 175 | |
| 176 | const instance = ( |
| 177 | <div> |
| 178 | {div} |
| 179 | {[[span]]} |
| 180 | {[a]} |
| 181 | {'string'} |
| 182 | {1234} |
| 183 | {true} |
| 184 | {false} |
| 185 | {null} |
| 186 | {undefined} |
| 187 | {9n} |
| 188 | </div> |
| 189 | ); |
| 190 | |
| 191 | function assertCalls() { |
| 192 | expect(callback).toHaveBeenCalledTimes(10); |
| 193 | expect(callback).toHaveBeenCalledWith(div, 0); |
| 194 | expect(callback).toHaveBeenCalledWith(span, 1); |
| 195 | expect(callback).toHaveBeenCalledWith(a, 2); |
| 196 | expect(callback).toHaveBeenCalledWith('string', 3); |
| 197 | expect(callback).toHaveBeenCalledWith(1234, 4); |
| 198 | expect(callback).toHaveBeenCalledWith(null, 5); |
| 199 | expect(callback).toHaveBeenCalledWith(null, 6); |
| 200 | expect(callback).toHaveBeenCalledWith(null, 7); |
| 201 | expect(callback).toHaveBeenCalledWith(null, 8); |
| 202 | expect(callback).toHaveBeenCalledWith(9n, 9); |
| 203 | callback.mockClear(); |
| 204 | } |
| 205 | |
| 206 | React.Children.forEach(instance.props.children, callback, context); |
| 207 | assertCalls(); |
| 208 | |
| 209 | const mappedChildren = React.Children.map( |
| 210 | instance.props.children, |
| 211 | callback, |
| 212 | context, |
| 213 | ); |
| 214 | assertCalls(); |
| 215 | expect(mappedChildren).toEqual([ |
| 216 | <div key=".$divNode" />, |
| 217 | <span key=".1:0:$spanNode" />, |
| 218 | <a key=".2:$aNode" />, |
| 219 | 'string', |
| 220 | 1234, |
| 221 | 9n, |
| 222 | ]); |
| 223 | }); |
| 224 | |
| 225 | it('should be called for each child in nested structure', () => { |
| 226 | const zero = <div key="keyZero" />; |
| 227 | const one = null; |
| 228 | const two = <div key="keyTwo" />; |
| 229 | const three = null; |
| 230 | const four = <div key="keyFour" />; |
| 231 | const five = <div key="keyFive" />; |
| 232 | |
| 233 | const context = {}; |
| 234 | const callback = jest.fn().mockImplementation(function (kid) { |
| 235 | return kid; |
| 236 | }); |
| 237 | |
| 238 | const instance = <div>{[[zero, one, two], [three, four], five]}</div>; |
| 239 | |
| 240 | function assertCalls() { |
| 241 | expect(callback).toHaveBeenCalledTimes(6); |
| 242 | expect(callback).toHaveBeenCalledWith(zero, 0); |
| 243 | expect(callback).toHaveBeenCalledWith(one, 1); |
| 244 | expect(callback).toHaveBeenCalledWith(two, 2); |
| 245 | expect(callback).toHaveBeenCalledWith(three, 3); |
| 246 | expect(callback).toHaveBeenCalledWith(four, 4); |
| 247 | expect(callback).toHaveBeenCalledWith(five, 5); |
| 248 | callback.mockClear(); |
| 249 | } |
| 250 | |
| 251 | React.Children.forEach(instance.props.children, callback, context); |
| 252 | assertCalls(); |
| 253 | |
| 254 | const mappedChildren = React.Children.map( |
| 255 | instance.props.children, |
| 256 | callback, |
| 257 | context, |
| 258 | ); |
| 259 | assertCalls(); |
| 260 | expect(mappedChildren).toEqual([ |
| 261 | <div key=".0:$keyZero" />, |
| 262 | <div key=".0:$keyTwo" />, |
| 263 | <div key=".1:$keyFour" />, |
| 264 | <div key=".$keyFive" />, |
| 265 | ]); |
| 266 | }); |
| 267 | |
| 268 | it('should retain key across two mappings', () => { |
| 269 | const zeroForceKey = <div key="keyZero" />; |
| 270 | const oneForceKey = <div key="keyOne" />; |
| 271 | const context = {}; |
| 272 | const callback = jest.fn().mockImplementation(function (kid) { |
| 273 | expect(this).toBe(context); |
| 274 | return kid; |
| 275 | }); |
| 276 | |
| 277 | const forcedKeys = ( |
| 278 | <div> |
| 279 | {zeroForceKey} |
| 280 | {oneForceKey} |
| 281 | </div> |
| 282 | ); |
| 283 | |
| 284 | function assertCalls() { |
| 285 | expect(callback).toHaveBeenCalledWith(zeroForceKey, 0); |
| 286 | expect(callback).toHaveBeenCalledWith(oneForceKey, 1); |
| 287 | callback.mockClear(); |
| 288 | } |
| 289 | |
| 290 | React.Children.forEach(forcedKeys.props.children, callback, context); |
| 291 | assertCalls(); |
| 292 | |
| 293 | const mappedChildren = React.Children.map( |
| 294 | forcedKeys.props.children, |
| 295 | callback, |
| 296 | context, |
| 297 | ); |
| 298 | assertCalls(); |
| 299 | expect(mappedChildren).toEqual([ |
| 300 | <div key=".$keyZero" />, |
| 301 | <div key=".$keyOne" />, |
| 302 | ]); |
| 303 | }); |
| 304 | |
| 305 | it('should be called for each child in an iterable without keys', async () => { |
| 306 | const threeDivIterable = { |
| 307 | '@@iterator': function () { |
| 308 | let i = 0; |
| 309 | return { |
| 310 | next: function () { |
| 311 | if (i++ < 3) { |
| 312 | return {value: <div />, done: false}; |
| 313 | } else { |
| 314 | return {value: undefined, done: true}; |
| 315 | } |
| 316 | }, |
| 317 | }; |
| 318 | }, |
| 319 | }; |
| 320 | |
| 321 | const context = {}; |
| 322 | const callback = jest.fn().mockImplementation(function (kid) { |
| 323 | expect(this).toBe(context); |
| 324 | return kid; |
| 325 | }); |
| 326 | |
| 327 | function assertCalls() { |
| 328 | expect(callback).toHaveBeenCalledTimes(3); |
| 329 | expect(callback).toHaveBeenCalledWith(<div />, 0); |
| 330 | expect(callback).toHaveBeenCalledWith(<div />, 1); |
| 331 | expect(callback).toHaveBeenCalledWith(<div />, 2); |
| 332 | callback.mockClear(); |
| 333 | } |
| 334 | |
| 335 | const instance = <div>{threeDivIterable}</div>; |
| 336 | |
| 337 | React.Children.forEach(instance.props.children, callback, context); |
| 338 | |
| 339 | assertCalls(); |
| 340 | |
| 341 | const mappedChildren = React.Children.map( |
| 342 | instance.props.children, |
| 343 | callback, |
| 344 | context, |
| 345 | ); |
| 346 | assertCalls(); |
| 347 | expect(mappedChildren).toEqual([ |
| 348 | <div key=".0" />, |
| 349 | <div key=".1" />, |
| 350 | <div key=".2" />, |
| 351 | ]); |
| 352 | |
| 353 | const container = document.createElement('div'); |
| 354 | const root = ReactDOMClient.createRoot(container); |
| 355 | await act(() => { |
| 356 | root.render(instance); |
| 357 | }); |
| 358 | assertConsoleErrorDev([ |
| 359 | 'Each child in a list should have a unique "key" prop.\n\n' + |
| 360 | 'Check the top-level render call using <div>. It was passed a child from div.' + |
| 361 | ' See https://react.dev/link/warning-keys for more information.\n' + |
| 362 | ' in div (at **)', |
| 363 | ]); |
| 364 | }); |
| 365 | |
| 366 | it('should be called for each child in an iterable with keys', () => { |
| 367 | const threeDivIterable = { |
| 368 | '@@iterator': function () { |
| 369 | let i = 0; |
| 370 | return { |
| 371 | next: function () { |
| 372 | if (i++ < 3) { |
| 373 | return {value: <div key={'#' + i} />, done: false}; |
| 374 | } else { |
| 375 | return {value: undefined, done: true}; |
| 376 | } |
| 377 | }, |
| 378 | }; |
| 379 | }, |
| 380 | }; |
| 381 | |
| 382 | const context = {}; |
| 383 | const callback = jest.fn().mockImplementation(function (kid) { |
| 384 | expect(this).toBe(context); |
| 385 | return kid; |
| 386 | }); |
| 387 | |
| 388 | const instance = <div>{threeDivIterable}</div>; |
| 389 | |
| 390 | function assertCalls() { |
| 391 | expect(callback).toHaveBeenCalledTimes(3); |
| 392 | expect(callback).toHaveBeenCalledWith(<div key="#1" />, 0); |
| 393 | expect(callback).toHaveBeenCalledWith(<div key="#2" />, 1); |
| 394 | expect(callback).toHaveBeenCalledWith(<div key="#3" />, 2); |
| 395 | callback.mockClear(); |
| 396 | } |
| 397 | |
| 398 | React.Children.forEach(instance.props.children, callback, context); |
| 399 | assertCalls(); |
| 400 | |
| 401 | const mappedChildren = React.Children.map( |
| 402 | instance.props.children, |
| 403 | callback, |
| 404 | context, |
| 405 | ); |
| 406 | assertCalls(); |
| 407 | expect(mappedChildren).toEqual([ |
| 408 | <div key=".$#1" />, |
| 409 | <div key=".$#2" />, |
| 410 | <div key=".$#3" />, |
| 411 | ]); |
| 412 | }); |
| 413 | |
| 414 | it('should not enumerate enumerable numbers (#4776)', () => { |
| 415 | /*eslint-disable no-extend-native */ |
| 416 | Number.prototype['@@iterator'] = function () { |
| 417 | throw new Error('number iterator called'); |
| 418 | }; |
| 419 | /*eslint-enable no-extend-native */ |
| 420 | |
| 421 | try { |
| 422 | const instance = ( |
| 423 | <div> |
| 424 | {5} |
| 425 | {12} |
| 426 | {13} |
| 427 | </div> |
| 428 | ); |
| 429 | |
| 430 | const context = {}; |
| 431 | const callback = jest.fn().mockImplementation(function (kid) { |
| 432 | expect(this).toBe(context); |
| 433 | return kid; |
| 434 | }); |
| 435 | |
| 436 | const assertCalls = function () { |
| 437 | expect(callback).toHaveBeenCalledTimes(3); |
| 438 | expect(callback).toHaveBeenCalledWith(5, 0); |
| 439 | expect(callback).toHaveBeenCalledWith(12, 1); |
| 440 | expect(callback).toHaveBeenCalledWith(13, 2); |
| 441 | callback.mockClear(); |
| 442 | }; |
| 443 | |
| 444 | React.Children.forEach(instance.props.children, callback, context); |
| 445 | assertCalls(); |
| 446 | |
| 447 | const mappedChildren = React.Children.map( |
| 448 | instance.props.children, |
| 449 | callback, |
| 450 | context, |
| 451 | ); |
| 452 | assertCalls(); |
| 453 | expect(mappedChildren).toEqual([5, 12, 13]); |
| 454 | } finally { |
| 455 | delete Number.prototype['@@iterator']; |
| 456 | } |
| 457 | }); |
| 458 | |
| 459 | it('should allow extension of native prototypes', () => { |
| 460 | /*eslint-disable no-extend-native */ |
| 461 | String.prototype.key = 'react'; |
| 462 | Number.prototype.key = 'rocks'; |
| 463 | /*eslint-enable no-extend-native */ |
| 464 | |
| 465 | const instance = ( |
| 466 | <div> |
| 467 | {'a'} |
| 468 | {13} |
| 469 | </div> |
| 470 | ); |
| 471 | |
| 472 | const context = {}; |
| 473 | const callback = jest.fn().mockImplementation(function (kid) { |
| 474 | expect(this).toBe(context); |
| 475 | return kid; |
| 476 | }); |
| 477 | |
| 478 | function assertCalls() { |
| 479 | expect(callback).toHaveBeenCalledTimes(2); |
| 480 | expect(callback).toHaveBeenCalledWith('a', 0); |
| 481 | expect(callback).toHaveBeenCalledWith(13, 1); |
| 482 | callback.mockClear(); |
| 483 | } |
| 484 | |
| 485 | React.Children.forEach(instance.props.children, callback, context); |
| 486 | assertCalls(); |
| 487 | |
| 488 | const mappedChildren = React.Children.map( |
| 489 | instance.props.children, |
| 490 | callback, |
| 491 | context, |
| 492 | ); |
| 493 | assertCalls(); |
| 494 | expect(mappedChildren).toEqual(['a', 13]); |
| 495 | |
| 496 | delete String.prototype.key; |
| 497 | delete Number.prototype.key; |
| 498 | }); |
| 499 | |
| 500 | it('should pass key to returned component', () => { |
| 501 | const mapFn = function (kid, index) { |
| 502 | return <div>{kid}</div>; |
| 503 | }; |
| 504 | |
| 505 | const simpleKid = <span key="simple" />; |
| 506 | |
| 507 | const instance = <div>{simpleKid}</div>; |
| 508 | const mappedChildren = React.Children.map(instance.props.children, mapFn); |
| 509 | |
| 510 | expect(React.Children.count(mappedChildren)).toBe(1); |
| 511 | expect(mappedChildren[0]).not.toBe(simpleKid); |
| 512 | expect(mappedChildren[0].props.children).toBe(simpleKid); |
| 513 | expect(mappedChildren[0].key).toBe('.$simple'); |
| 514 | }); |
| 515 | |
| 516 | it('should invoke callback with the right context', () => { |
| 517 | let lastContext; |
| 518 | const callback = function (kid, index) { |
| 519 | lastContext = this; |
| 520 | return this; |
| 521 | }; |
| 522 | |
| 523 | // TODO: Use an object to test, after non-object fragments has fully landed. |
| 524 | const scopeTester = 'scope tester'; |
| 525 | |
| 526 | const simpleKid = <span key="simple" />; |
| 527 | const instance = <div>{simpleKid}</div>; |
| 528 | React.Children.forEach(instance.props.children, callback, scopeTester); |
| 529 | expect(lastContext).toBe(scopeTester); |
| 530 | |
| 531 | const mappedChildren = React.Children.map( |
| 532 | instance.props.children, |
| 533 | callback, |
| 534 | scopeTester, |
| 535 | ); |
| 536 | |
| 537 | expect(React.Children.count(mappedChildren)).toBe(1); |
| 538 | expect(mappedChildren[0]).toBe(scopeTester); |
| 539 | }); |
| 540 | |
| 541 | it('should be called for each child in array', () => { |
| 542 | const zero = <div key="keyZero" />; |
| 543 | const one = null; |
| 544 | const two = <div key="keyTwo" />; |
| 545 | const three = null; |
| 546 | const four = <div key="keyFour" />; |
| 547 | |
| 548 | const mapped = [ |
| 549 | <div key="giraffe" />, // Key should be joined to obj key |
| 550 | null, // Key should be added even if we don't supply it! |
| 551 | <div />, // Key should be added even if not supplied! |
| 552 | <span />, // Map from null to something. |
| 553 | <div key="keyFour" />, |
| 554 | ]; |
| 555 | const callback = jest.fn().mockImplementation(function (kid, index) { |
| 556 | return mapped[index]; |
| 557 | }); |
| 558 | |
| 559 | const instance = ( |
| 560 | <div> |
| 561 | {zero} |
| 562 | {one} |
| 563 | {two} |
| 564 | {three} |
| 565 | {four} |
| 566 | </div> |
| 567 | ); |
| 568 | |
| 569 | React.Children.forEach(instance.props.children, callback); |
| 570 | expect(callback).toHaveBeenCalledWith(zero, 0); |
| 571 | expect(callback).toHaveBeenCalledWith(one, 1); |
| 572 | expect(callback).toHaveBeenCalledWith(two, 2); |
| 573 | expect(callback).toHaveBeenCalledWith(three, 3); |
| 574 | expect(callback).toHaveBeenCalledWith(four, 4); |
| 575 | callback.mockClear(); |
| 576 | |
| 577 | const mappedChildren = React.Children.map( |
| 578 | instance.props.children, |
| 579 | callback, |
| 580 | ); |
| 581 | expect(callback).toHaveBeenCalledTimes(5); |
| 582 | expect(React.Children.count(mappedChildren)).toBe(4); |
| 583 | // Keys default to indices. |
| 584 | expect([ |
| 585 | mappedChildren[0].key, |
| 586 | mappedChildren[1].key, |
| 587 | mappedChildren[2].key, |
| 588 | mappedChildren[3].key, |
| 589 | ]).toEqual(['giraffe/.$keyZero', '.$keyTwo', '.3', '.$keyFour']); |
| 590 | |
| 591 | expect(callback).toHaveBeenCalledWith(zero, 0); |
| 592 | expect(callback).toHaveBeenCalledWith(one, 1); |
| 593 | expect(callback).toHaveBeenCalledWith(two, 2); |
| 594 | expect(callback).toHaveBeenCalledWith(three, 3); |
| 595 | expect(callback).toHaveBeenCalledWith(four, 4); |
| 596 | |
| 597 | expect(mappedChildren[0]).toEqual(<div key="giraffe/.$keyZero" />); |
| 598 | expect(mappedChildren[1]).toEqual(<div key=".$keyTwo" />); |
| 599 | expect(mappedChildren[2]).toEqual(<span key=".3" />); |
| 600 | expect(mappedChildren[3]).toEqual(<div key=".$keyFour" />); |
| 601 | }); |
| 602 | |
| 603 | it('should be called for each child in nested structure with mapping', () => { |
| 604 | const zero = <div key="keyZero" />; |
| 605 | const one = null; |
| 606 | const two = <div key="keyTwo" />; |
| 607 | const three = null; |
| 608 | const four = <div key="keyFour" />; |
| 609 | const five = <div key="keyFive" />; |
| 610 | |
| 611 | const zeroMapped = <div key="giraffe" />; // Key should be overridden |
| 612 | const twoMapped = <div />; // Key should be added even if not supplied! |
| 613 | const fourMapped = <div key="keyFour" />; |
| 614 | const fiveMapped = <div />; |
| 615 | |
| 616 | const callback = jest.fn().mockImplementation(function (kid) { |
| 617 | switch (kid) { |
| 618 | case zero: |
| 619 | return zeroMapped; |
| 620 | case two: |
| 621 | return twoMapped; |
| 622 | case four: |
| 623 | return fourMapped; |
| 624 | case five: |
| 625 | return fiveMapped; |
| 626 | default: |
| 627 | return kid; |
| 628 | } |
| 629 | }); |
| 630 | |
| 631 | const frag = [[zero, one, two], [three, four], five]; |
| 632 | const instance = <div>{[frag]}</div>; |
| 633 | |
| 634 | React.Children.forEach(instance.props.children, callback); |
| 635 | expect(callback).toHaveBeenCalledTimes(6); |
| 636 | expect(callback).toHaveBeenCalledWith(zero, 0); |
| 637 | expect(callback).toHaveBeenCalledWith(one, 1); |
| 638 | expect(callback).toHaveBeenCalledWith(two, 2); |
| 639 | expect(callback).toHaveBeenCalledWith(three, 3); |
| 640 | expect(callback).toHaveBeenCalledWith(four, 4); |
| 641 | expect(callback).toHaveBeenCalledWith(five, 5); |
| 642 | callback.mockClear(); |
| 643 | |
| 644 | const mappedChildren = React.Children.map( |
| 645 | instance.props.children, |
| 646 | callback, |
| 647 | ); |
| 648 | expect(callback).toHaveBeenCalledTimes(6); |
| 649 | expect(callback).toHaveBeenCalledWith(zero, 0); |
| 650 | expect(callback).toHaveBeenCalledWith(one, 1); |
| 651 | expect(callback).toHaveBeenCalledWith(two, 2); |
| 652 | expect(callback).toHaveBeenCalledWith(three, 3); |
| 653 | expect(callback).toHaveBeenCalledWith(four, 4); |
| 654 | expect(callback).toHaveBeenCalledWith(five, 5); |
| 655 | |
| 656 | expect(React.Children.count(mappedChildren)).toBe(4); |
| 657 | // Keys default to indices. |
| 658 | expect([ |
| 659 | mappedChildren[0].key, |
| 660 | mappedChildren[1].key, |
| 661 | mappedChildren[2].key, |
| 662 | mappedChildren[3].key, |
| 663 | ]).toEqual([ |
| 664 | 'giraffe/.0:0:$keyZero', |
| 665 | '.0:0:$keyTwo', |
| 666 | '.0:1:$keyFour', |
| 667 | '.0:$keyFive', |
| 668 | ]); |
| 669 | |
| 670 | expect(mappedChildren[0]).toEqual(<div key="giraffe/.0:0:$keyZero" />); |
| 671 | expect(mappedChildren[1]).toEqual(<div key=".0:0:$keyTwo" />); |
| 672 | expect(mappedChildren[2]).toEqual(<div key=".0:1:$keyFour" />); |
| 673 | expect(mappedChildren[3]).toEqual(<div key=".0:$keyFive" />); |
| 674 | }); |
| 675 | |
| 676 | it('should retain key across two mappings with conditions', () => { |
| 677 | const zeroForceKey = <div key="keyZero" />; |
| 678 | const oneForceKey = <div key="keyOne" />; |
| 679 | |
| 680 | // Key should be joined to object key |
| 681 | const zeroForceKeyMapped = <div key="giraffe" />; |
| 682 | // Key should be added even if we don't supply it! |
| 683 | const oneForceKeyMapped = <div />; |
| 684 | |
| 685 | const mapFn = function (kid, index) { |
| 686 | return index === 0 ? zeroForceKeyMapped : oneForceKeyMapped; |
| 687 | }; |
| 688 | |
| 689 | const forcedKeys = ( |
| 690 | <div> |
| 691 | {zeroForceKey} |
| 692 | {oneForceKey} |
| 693 | </div> |
| 694 | ); |
| 695 | |
| 696 | const expectedForcedKeys = ['giraffe/.$keyZero', '.$keyOne']; |
| 697 | const mappedChildrenForcedKeys = React.Children.map( |
| 698 | forcedKeys.props.children, |
| 699 | mapFn, |
| 700 | ); |
| 701 | const mappedForcedKeys = mappedChildrenForcedKeys.map(c => c.key); |
| 702 | expect(mappedForcedKeys).toEqual(expectedForcedKeys); |
| 703 | |
| 704 | const expectedRemappedForcedKeys = [ |
| 705 | 'giraffe/.$giraffe/.$keyZero', |
| 706 | '.$.$keyOne', |
| 707 | ]; |
| 708 | const remappedChildrenForcedKeys = React.Children.map( |
| 709 | mappedChildrenForcedKeys, |
| 710 | mapFn, |
| 711 | ); |
| 712 | expect(remappedChildrenForcedKeys.map(c => c.key)).toEqual( |
| 713 | expectedRemappedForcedKeys, |
| 714 | ); |
| 715 | }); |
| 716 | |
| 717 | it('should not throw if key provided is a dupe with array key', () => { |
| 718 | const zero = <div />; |
| 719 | const one = <div key="0" />; |
| 720 | |
| 721 | const mapFn = function () { |
| 722 | return null; |
| 723 | }; |
| 724 | |
| 725 | const instance = ( |
| 726 | <div> |
| 727 | {zero} |
| 728 | {one} |
| 729 | </div> |
| 730 | ); |
| 731 | |
| 732 | expect(function () { |
| 733 | React.Children.map(instance.props.children, mapFn); |
| 734 | }).not.toThrow(); |
| 735 | }); |
| 736 | |
| 737 | it('should use the same key for a cloned element', () => { |
| 738 | const instance = ( |
| 739 | <div> |
| 740 | <div /> |
| 741 | </div> |
| 742 | ); |
| 743 | |
| 744 | const mapped = React.Children.map( |
| 745 | instance.props.children, |
| 746 | element => element, |
| 747 | ); |
| 748 | |
| 749 | const mappedWithClone = React.Children.map( |
| 750 | instance.props.children, |
| 751 | element => React.cloneElement(element), |
| 752 | ); |
| 753 | |
| 754 | expect(mapped[0].key).toBe(mappedWithClone[0].key); |
| 755 | }); |
| 756 | |
| 757 | it('should use the same key for a cloned element with key', () => { |
| 758 | const instance = ( |
| 759 | <div> |
| 760 | <div key="unique" /> |
| 761 | </div> |
| 762 | ); |
| 763 | |
| 764 | const mapped = React.Children.map( |
| 765 | instance.props.children, |
| 766 | element => element, |
| 767 | ); |
| 768 | |
| 769 | const mappedWithClone = React.Children.map( |
| 770 | instance.props.children, |
| 771 | element => React.cloneElement(element, {key: 'unique'}), |
| 772 | ); |
| 773 | |
| 774 | expect(mapped[0].key).toBe(mappedWithClone[0].key); |
| 775 | }); |
| 776 | |
| 777 | it('should return 0 for null children', () => { |
| 778 | const numberOfChildren = React.Children.count(null); |
| 779 | expect(numberOfChildren).toBe(0); |
| 780 | }); |
| 781 | |
| 782 | it('should return 0 for undefined children', () => { |
| 783 | const numberOfChildren = React.Children.count(undefined); |
| 784 | expect(numberOfChildren).toBe(0); |
| 785 | }); |
| 786 | |
| 787 | it('should return 1 for single child', () => { |
| 788 | const simpleKid = <span key="simple" />; |
| 789 | const instance = <div>{simpleKid}</div>; |
| 790 | const numberOfChildren = React.Children.count(instance.props.children); |
| 791 | expect(numberOfChildren).toBe(1); |
| 792 | }); |
| 793 | |
| 794 | it('should count the number of children in flat structure', () => { |
| 795 | const zero = <div key="keyZero" />; |
| 796 | const one = null; |
| 797 | const two = <div key="keyTwo" />; |
| 798 | const three = null; |
| 799 | const four = <div key="keyFour" />; |
| 800 | |
| 801 | const instance = ( |
| 802 | <div> |
| 803 | {zero} |
| 804 | {one} |
| 805 | {two} |
| 806 | {three} |
| 807 | {four} |
| 808 | </div> |
| 809 | ); |
| 810 | const numberOfChildren = React.Children.count(instance.props.children); |
| 811 | expect(numberOfChildren).toBe(5); |
| 812 | }); |
| 813 | |
| 814 | it('should count the number of children in nested structure', () => { |
| 815 | const zero = <div key="keyZero" />; |
| 816 | const one = null; |
| 817 | const two = <div key="keyTwo" />; |
| 818 | const three = null; |
| 819 | const four = <div key="keyFour" />; |
| 820 | const five = <div key="keyFive" />; |
| 821 | |
| 822 | const instance = ( |
| 823 | <div>{[[[zero, one, two], [three, four], five], null]}</div> |
| 824 | ); |
| 825 | const numberOfChildren = React.Children.count(instance.props.children); |
| 826 | expect(numberOfChildren).toBe(7); |
| 827 | }); |
| 828 | |
| 829 | it('should flatten children to an array', () => { |
| 830 | expect(React.Children.toArray(undefined)).toEqual([]); |
| 831 | expect(React.Children.toArray(null)).toEqual([]); |
| 832 | |
| 833 | expect(React.Children.toArray(<div />).length).toBe(1); |
| 834 | expect(React.Children.toArray([<div />]).length).toBe(1); |
| 835 | expect(React.Children.toArray(<div />)[0].key).toBe( |
| 836 | React.Children.toArray([<div />])[0].key, |
| 837 | ); |
| 838 | |
| 839 | const flattened = React.Children.toArray([ |
| 840 | [<div key="apple" />, <div key="banana" />, <div key="camel" />], |
| 841 | [<div key="banana" />, <div key="camel" />, <div key="deli" />], |
| 842 | ]); |
| 843 | expect(flattened.length).toBe(6); |
| 844 | expect(flattened[1].key).toContain('banana'); |
| 845 | expect(flattened[3].key).toContain('banana'); |
| 846 | expect(flattened[1].key).not.toBe(flattened[3].key); |
| 847 | |
| 848 | const reversed = React.Children.toArray([ |
| 849 | [<div key="camel" />, <div key="banana" />, <div key="apple" />], |
| 850 | [<div key="deli" />, <div key="camel" />, <div key="banana" />], |
| 851 | ]); |
| 852 | expect(flattened[0].key).toBe(reversed[2].key); |
| 853 | expect(flattened[1].key).toBe(reversed[1].key); |
| 854 | expect(flattened[2].key).toBe(reversed[0].key); |
| 855 | expect(flattened[3].key).toBe(reversed[5].key); |
| 856 | expect(flattened[4].key).toBe(reversed[4].key); |
| 857 | expect(flattened[5].key).toBe(reversed[3].key); |
| 858 | |
| 859 | // null/undefined/bool are all omitted |
| 860 | expect(React.Children.toArray([1, 'two', null, undefined, true])).toEqual([ |
| 861 | 1, |
| 862 | 'two', |
| 863 | ]); |
| 864 | }); |
| 865 | |
| 866 | it('warns for mapped list children without keys', async () => { |
| 867 | spyOnDev(console, 'error').mockImplementation(() => {}); |
| 868 | function ComponentRenderingMappedChildren({children}) { |
| 869 | return ( |
| 870 | <div> |
| 871 | {React.Children.map(children, child => ( |
| 872 | <div /> |
| 873 | ))} |
| 874 | </div> |
| 875 | ); |
| 876 | } |
| 877 | |
| 878 | const container = document.createElement('div'); |
| 879 | const root = ReactDOMClient.createRoot(container); |
| 880 | await act(() => { |
| 881 | root.render( |
| 882 | <ComponentRenderingMappedChildren> |
| 883 | {[<div />]} |
| 884 | </ComponentRenderingMappedChildren>, |
| 885 | ); |
| 886 | }); |
| 887 | if (__DEV__) { |
| 888 | const calls = console.error.mock.calls; |
| 889 | console.error.mockRestore(); |
| 890 | expect(calls.length).toBe(1); |
| 891 | expect(calls[0][0]).toEqual( |
| 892 | 'Each child in a list should have a unique "key" prop.%s%s See https://react.dev/link/warning-keys for more information.', |
| 893 | ); |
| 894 | } |
| 895 | }); |
| 896 | |
| 897 | it('does not warn for mapped static children without keys', async () => { |
| 898 | function ComponentRenderingMappedChildren({children}) { |
| 899 | return ( |
| 900 | <div> |
| 901 | {React.Children.map(children, child => ( |
| 902 | <div /> |
| 903 | ))} |
| 904 | </div> |
| 905 | ); |
| 906 | } |
| 907 | |
| 908 | const container = document.createElement('div'); |
| 909 | const root = ReactDOMClient.createRoot(container); |
| 910 | await act(() => { |
| 911 | root.render( |
| 912 | <ComponentRenderingMappedChildren> |
| 913 | <div /> |
| 914 | <div /> |
| 915 | </ComponentRenderingMappedChildren>, |
| 916 | ); |
| 917 | }); |
| 918 | }); |
| 919 | |
| 920 | it('warns for cloned list children without keys', async () => { |
| 921 | function ComponentRenderingClonedChildren({children}) { |
| 922 | return ( |
| 923 | <div> |
| 924 | {React.Children.map(children, child => React.cloneElement(child))} |
| 925 | </div> |
| 926 | ); |
| 927 | } |
| 928 | |
| 929 | const container = document.createElement('div'); |
| 930 | const root = ReactDOMClient.createRoot(container); |
| 931 | await act(() => { |
| 932 | root.render( |
| 933 | <ComponentRenderingClonedChildren> |
| 934 | {[<div />]} |
| 935 | </ComponentRenderingClonedChildren>, |
| 936 | ); |
| 937 | }); |
| 938 | assertConsoleErrorDev([ |
| 939 | 'Each child in a list should have a unique "key" prop.\n\n' + |
| 940 | 'Check the render method of `ComponentRenderingClonedChildren`.' + |
| 941 | ' See https://react.dev/link/warning-keys for more information.\n' + |
| 942 | ' in div (at **)', |
| 943 | ]); |
| 944 | }); |
| 945 | |
| 946 | it('does not warn for cloned static children without keys', async () => { |
| 947 | function ComponentRenderingClonedChildren({children}) { |
| 948 | return ( |
| 949 | <div> |
| 950 | {React.Children.map(children, child => React.cloneElement(child))} |
| 951 | </div> |
| 952 | ); |
| 953 | } |
| 954 | |
| 955 | const container = document.createElement('div'); |
| 956 | const root = ReactDOMClient.createRoot(container); |
| 957 | await act(() => { |
| 958 | root.render( |
| 959 | <ComponentRenderingClonedChildren> |
| 960 | <div /> |
| 961 | <div /> |
| 962 | </ComponentRenderingClonedChildren>, |
| 963 | ); |
| 964 | }); |
| 965 | }); |
| 966 | |
| 967 | it('warns for flattened list children without keys', async () => { |
| 968 | function ComponentRenderingFlattenedChildren({children}) { |
| 969 | return <div>{React.Children.toArray(children)}</div>; |
| 970 | } |
| 971 | |
| 972 | const container = document.createElement('div'); |
| 973 | const root = ReactDOMClient.createRoot(container); |
| 974 | await act(() => { |
| 975 | root.render( |
| 976 | <ComponentRenderingFlattenedChildren> |
| 977 | {[<div />]} |
| 978 | </ComponentRenderingFlattenedChildren>, |
| 979 | ); |
| 980 | }); |
| 981 | assertConsoleErrorDev([ |
| 982 | 'Each child in a list should have a unique "key" prop.\n\n' + |
| 983 | 'Check the render method of `ComponentRenderingFlattenedChildren`.' + |
| 984 | ' See https://react.dev/link/warning-keys for more information.\n' + |
| 985 | ' in div (at **)', |
| 986 | ]); |
| 987 | }); |
| 988 | |
| 989 | it('does not warn for flattened static children without keys', async () => { |
| 990 | function ComponentRenderingFlattenedChildren({children}) { |
| 991 | return <div>{React.Children.toArray(children)}</div>; |
| 992 | } |
| 993 | |
| 994 | const container = document.createElement('div'); |
| 995 | const root = ReactDOMClient.createRoot(container); |
| 996 | await act(() => { |
| 997 | root.render( |
| 998 | <ComponentRenderingFlattenedChildren> |
| 999 | <div /> |
| 1000 | <div /> |
| 1001 | </ComponentRenderingFlattenedChildren>, |
| 1002 | ); |
| 1003 | }); |
| 1004 | }); |
| 1005 | |
| 1006 | it('does not throw on children without `_store`', async () => { |
| 1007 | function ComponentRenderingFlattenedChildren({children}) { |
| 1008 | return <div>{React.Children.toArray(children)}</div>; |
| 1009 | } |
| 1010 | |
| 1011 | const source = <div />; |
| 1012 | const productionElement = {}; |
| 1013 | Object.entries(source).forEach(([key, value]) => { |
| 1014 | if (key !== '_owner' && key !== '_store') { |
| 1015 | productionElement[key] = value; |
| 1016 | } |
| 1017 | }); |
| 1018 | Object.freeze(productionElement); |
| 1019 | |
| 1020 | const container = document.createElement('div'); |
| 1021 | const root = ReactDOMClient.createRoot(container); |
| 1022 | await act(() => { |
| 1023 | root.render( |
| 1024 | <ComponentRenderingFlattenedChildren> |
| 1025 | {productionElement} |
| 1026 | </ComponentRenderingFlattenedChildren>, |
| 1027 | ); |
| 1028 | }); |
| 1029 | }); |
| 1030 | |
| 1031 | it('should escape keys', () => { |
| 1032 | const zero = <div key="1" />; |
| 1033 | const one = <div key="1=::=2" />; |
| 1034 | const instance = ( |
| 1035 | <div> |
| 1036 | {zero} |
| 1037 | {one} |
| 1038 | </div> |
| 1039 | ); |
| 1040 | const mappedChildren = React.Children.map( |
| 1041 | instance.props.children, |
| 1042 | kid => kid, |
| 1043 | ); |
| 1044 | expect(mappedChildren).toEqual([ |
| 1045 | <div key=".$1" />, |
| 1046 | <div key=".$1=0=2=2=02" />, |
| 1047 | ]); |
| 1048 | }); |
| 1049 | |
| 1050 | it('should combine keys when map returns an array', () => { |
| 1051 | const instance = ( |
| 1052 | <div> |
| 1053 | <div key="a" /> |
| 1054 | {false} |
| 1055 | <div key="b" /> |
| 1056 | <p /> |
| 1057 | </div> |
| 1058 | ); |
| 1059 | const mappedChildren = React.Children.map( |
| 1060 | instance.props.children, |
| 1061 | // Try a few things: keyed, unkeyed, hole, and a cloned element. |
| 1062 | kid => [ |
| 1063 | <span key="x" />, |
| 1064 | null, |
| 1065 | <span key="y" />, |
| 1066 | kid, |
| 1067 | kid && React.cloneElement(kid, {key: 'z'}), |
| 1068 | <hr />, |
| 1069 | ], |
| 1070 | ); |
| 1071 | expect(mappedChildren.length).toBe(18); |
| 1072 | |
| 1073 | // <div key="a"> |
| 1074 | expect(mappedChildren[0].type).toBe('span'); |
| 1075 | expect(mappedChildren[0].key).toBe('.$a/.$x'); |
| 1076 | expect(mappedChildren[1].type).toBe('span'); |
| 1077 | expect(mappedChildren[1].key).toBe('.$a/.$y'); |
| 1078 | expect(mappedChildren[2].type).toBe('div'); |
| 1079 | expect(mappedChildren[2].key).toBe('.$a/.$a'); |
| 1080 | expect(mappedChildren[3].type).toBe('div'); |
| 1081 | expect(mappedChildren[3].key).toBe('.$a/.$z'); |
| 1082 | expect(mappedChildren[4].type).toBe('hr'); |
| 1083 | expect(mappedChildren[4].key).toBe('.$a/.5'); |
| 1084 | |
| 1085 | // false |
| 1086 | expect(mappedChildren[5].type).toBe('span'); |
| 1087 | expect(mappedChildren[5].key).toBe('.1/.$x'); |
| 1088 | expect(mappedChildren[6].type).toBe('span'); |
| 1089 | expect(mappedChildren[6].key).toBe('.1/.$y'); |
| 1090 | expect(mappedChildren[7].type).toBe('hr'); |
| 1091 | expect(mappedChildren[7].key).toBe('.1/.5'); |
| 1092 | |
| 1093 | // <div key="b"> |
| 1094 | expect(mappedChildren[8].type).toBe('span'); |
| 1095 | expect(mappedChildren[8].key).toBe('.$b/.$x'); |
| 1096 | expect(mappedChildren[9].type).toBe('span'); |
| 1097 | expect(mappedChildren[9].key).toBe('.$b/.$y'); |
| 1098 | expect(mappedChildren[10].type).toBe('div'); |
| 1099 | expect(mappedChildren[10].key).toBe('.$b/.$b'); |
| 1100 | expect(mappedChildren[11].type).toBe('div'); |
| 1101 | expect(mappedChildren[11].key).toBe('.$b/.$z'); |
| 1102 | expect(mappedChildren[12].type).toBe('hr'); |
| 1103 | expect(mappedChildren[12].key).toBe('.$b/.5'); |
| 1104 | |
| 1105 | // <p> |
| 1106 | expect(mappedChildren[13].type).toBe('span'); |
| 1107 | expect(mappedChildren[13].key).toBe('.3/.$x'); |
| 1108 | expect(mappedChildren[14].type).toBe('span'); |
| 1109 | expect(mappedChildren[14].key).toBe('.3/.$y'); |
| 1110 | expect(mappedChildren[15].type).toBe('p'); |
| 1111 | expect(mappedChildren[15].key).toBe('.3/.3'); |
| 1112 | expect(mappedChildren[16].type).toBe('p'); |
| 1113 | expect(mappedChildren[16].key).toBe('.3/.$z'); |
| 1114 | expect(mappedChildren[17].type).toBe('hr'); |
| 1115 | expect(mappedChildren[17].key).toBe('.3/.5'); |
| 1116 | }); |
| 1117 | |
| 1118 | it('should throw on object', () => { |
| 1119 | expect(function () { |
| 1120 | React.Children.forEach({a: 1, b: 2}, function () {}, null); |
| 1121 | }).toThrow( |
| 1122 | 'Objects are not valid as a React child (found: object with keys ' + |
| 1123 | '{a, b}).' + |
| 1124 | (__DEV__ |
| 1125 | ? ' If you meant to render a collection of children, use an ' + |
| 1126 | 'array instead.' |
| 1127 | : ''), |
| 1128 | ); |
| 1129 | }); |
| 1130 | |
| 1131 | it('should render React.lazy after suspending', async () => { |
| 1132 | const lazyElement = React.lazy(async () => ({default: <div key="hi" />})); |
| 1133 | function Component() { |
| 1134 | return React.Children.map([lazyElement], c => |
| 1135 | React.cloneElement(c, {children: 'hi'}), |
| 1136 | ); |
| 1137 | } |
| 1138 | const container = document.createElement('div'); |
| 1139 | const root = ReactDOMClient.createRoot(container); |
| 1140 | await act(() => { |
| 1141 | root.render(<Component />); |
| 1142 | }); |
| 1143 | |
| 1144 | expect(container.innerHTML).toBe('<div>hi</div>'); |
| 1145 | }); |
| 1146 | |
| 1147 | it('should render cached Promises after suspending', async () => { |
| 1148 | const promise = Promise.resolve(<div key="hi" />); |
| 1149 | function Component() { |
| 1150 | return React.Children.map([promise], c => |
| 1151 | React.cloneElement(c, {children: 'hi'}), |
| 1152 | ); |
| 1153 | } |
| 1154 | const container = document.createElement('div'); |
| 1155 | const root = ReactDOMClient.createRoot(container); |
| 1156 | await act(() => { |
| 1157 | root.render(<Component />); |
| 1158 | }); |
| 1159 | |
| 1160 | expect(container.innerHTML).toBe('<div>hi</div>'); |
| 1161 | }); |
| 1162 | |
| 1163 | it('should throw on regex', () => { |
| 1164 | // Really, we care about dates (#4840) but those have nondeterministic |
| 1165 | // serialization (timezones) so let's test a regex instead: |
| 1166 | expect(function () { |
| 1167 | React.Children.forEach(/abc/, function () {}, null); |
| 1168 | }).toThrow( |
| 1169 | 'Objects are not valid as a React child (found: /abc/).' + |
| 1170 | (__DEV__ |
| 1171 | ? ' If you meant to render a collection of children, use an ' + |
| 1172 | 'array instead.' |
| 1173 | : ''), |
| 1174 | ); |
| 1175 | }); |
| 1176 | |
| 1177 | describe('with fragments enabled', () => { |
| 1178 | it('warns for keys for arrays of elements in a fragment', async () => { |
| 1179 | class ComponentReturningArray extends React.Component { |
| 1180 | render() { |
| 1181 | return [<div />, <div />]; |
| 1182 | } |
| 1183 | } |
| 1184 | |
| 1185 | const container = document.createElement('div'); |
| 1186 | const root = ReactDOMClient.createRoot(container); |
| 1187 | await act(() => { |
| 1188 | root.render(<ComponentReturningArray />); |
| 1189 | }); |
| 1190 | assertConsoleErrorDev([ |
| 1191 | 'Each child in a list should have a unique "key" prop.' + |
| 1192 | '\n\nCheck the top-level render call using <ComponentReturningArray>. It was passed a child from ComponentReturningArray. ' + |
| 1193 | 'See https://react.dev/link/warning-keys for more information.' + |
| 1194 | '\n in div (at **)' + |
| 1195 | '\n in ComponentReturningArray (at **)', |
| 1196 | ]); |
| 1197 | }); |
| 1198 | |
| 1199 | it('does not warn when there are keys on elements in a fragment', async () => { |
| 1200 | class ComponentReturningArray extends React.Component { |
| 1201 | render() { |
| 1202 | return [<div key="foo" />, <div key="bar" />]; |
| 1203 | } |
| 1204 | } |
| 1205 | |
| 1206 | const container = document.createElement('div'); |
| 1207 | const root = ReactDOMClient.createRoot(container); |
| 1208 | await act(() => { |
| 1209 | root.render(<ComponentReturningArray />); |
| 1210 | }); |
| 1211 | }); |
| 1212 | |
| 1213 | it('warns for keys for arrays at the top level', async () => { |
| 1214 | const container = document.createElement('div'); |
| 1215 | const root = ReactDOMClient.createRoot(container); |
| 1216 | await act(() => { |
| 1217 | root.render([<div />, <div />]); |
| 1218 | }); |
| 1219 | assertConsoleErrorDev([ |
| 1220 | 'Each child in a list should have a unique "key" prop.' + |
| 1221 | '\n\nCheck the top-level render call using <Root>. ' + |
| 1222 | 'See https://react.dev/link/warning-keys for more information.' + |
| 1223 | '\n in div (at **)', |
| 1224 | ]); |
| 1225 | }); |
| 1226 | }); |
| 1227 | }); |