| 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 | let act; |
| 13 | let React; |
| 14 | let ReactDOMClient; |
| 15 | let assertConsoleErrorDev; |
| 16 | |
| 17 | describe('ReactElementClone', () => { |
| 18 | let ComponentClass; |
| 19 | |
| 20 | beforeEach(() => { |
| 21 | jest.resetModules(); |
| 22 | |
| 23 | ({act, assertConsoleErrorDev} = require('internal-test-utils')); |
| 24 | |
| 25 | React = require('react'); |
| 26 | ReactDOMClient = require('react-dom/client'); |
| 27 | |
| 28 | // NOTE: We're explicitly not using JSX here. This is intended to test |
| 29 | // classic JS without JSX. |
| 30 | ComponentClass = class extends React.Component { |
| 31 | render() { |
| 32 | return React.createElement('div'); |
| 33 | } |
| 34 | }; |
| 35 | }); |
| 36 | |
| 37 | it('should clone a DOM component with new props', async () => { |
| 38 | let div; |
| 39 | class Grandparent extends React.Component { |
| 40 | render() { |
| 41 | return ( |
| 42 | <Parent |
| 43 | child={<div ref={node => (div = node)} className="child" />} |
| 44 | /> |
| 45 | ); |
| 46 | } |
| 47 | } |
| 48 | class Parent extends React.Component { |
| 49 | render() { |
| 50 | return ( |
| 51 | <div className="parent"> |
| 52 | {React.cloneElement(this.props.child, {className: 'xyz'})} |
| 53 | </div> |
| 54 | ); |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 59 | await act(() => { |
| 60 | root.render(<Grandparent />); |
| 61 | }); |
| 62 | expect(div.className).toBe('xyz'); |
| 63 | }); |
| 64 | |
| 65 | it('should clone a composite component with new props', async () => { |
| 66 | let div; |
| 67 | class Child extends React.Component { |
| 68 | render() { |
| 69 | return ( |
| 70 | <div ref={node => (div = node)} className={this.props.className} /> |
| 71 | ); |
| 72 | } |
| 73 | } |
| 74 | class Grandparent extends React.Component { |
| 75 | render() { |
| 76 | return <Parent child={<Child className="child" />} />; |
| 77 | } |
| 78 | } |
| 79 | class Parent extends React.Component { |
| 80 | render() { |
| 81 | return ( |
| 82 | <div className="parent"> |
| 83 | {React.cloneElement(this.props.child, {className: 'xyz'})} |
| 84 | </div> |
| 85 | ); |
| 86 | } |
| 87 | } |
| 88 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 89 | await act(() => { |
| 90 | root.render(<Grandparent />); |
| 91 | }); |
| 92 | expect(div.className).toBe('xyz'); |
| 93 | }); |
| 94 | |
| 95 | it('does not fail if config has no prototype', () => { |
| 96 | const config = Object.create(null, {foo: {value: 1, enumerable: true}}); |
| 97 | React.cloneElement(<div />, config); |
| 98 | }); |
| 99 | |
| 100 | it('should keep the original ref if it is not overridden', async () => { |
| 101 | let component; |
| 102 | class Grandparent extends React.Component { |
| 103 | yoloRef = React.createRef(); |
| 104 | |
| 105 | componentDidMount() { |
| 106 | component = this; |
| 107 | } |
| 108 | |
| 109 | render() { |
| 110 | return <Parent child={<div ref={this.yoloRef} />} />; |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | class Parent extends React.Component { |
| 115 | render() { |
| 116 | return ( |
| 117 | <div>{React.cloneElement(this.props.child, {className: 'xyz'})}</div> |
| 118 | ); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 123 | await act(() => { |
| 124 | root.render(<Grandparent />); |
| 125 | }); |
| 126 | |
| 127 | expect(component.yoloRef.current.tagName).toBe('DIV'); |
| 128 | }); |
| 129 | |
| 130 | it('should transfer the key property', () => { |
| 131 | class Component extends React.Component { |
| 132 | render() { |
| 133 | return null; |
| 134 | } |
| 135 | } |
| 136 | const clone = React.cloneElement(<Component />, {key: 'xyz'}); |
| 137 | expect(clone.key).toBe('xyz'); |
| 138 | }); |
| 139 | |
| 140 | it('should transfer children', async () => { |
| 141 | class Component extends React.Component { |
| 142 | render() { |
| 143 | expect(this.props.children).toBe('xyz'); |
| 144 | return <div />; |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 149 | await act(() => { |
| 150 | root.render(React.cloneElement(<Component />, {children: 'xyz'})); |
| 151 | }); |
| 152 | }); |
| 153 | |
| 154 | it('should shallow clone children', async () => { |
| 155 | class Component extends React.Component { |
| 156 | render() { |
| 157 | expect(this.props.children).toBe('xyz'); |
| 158 | return <div />; |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 163 | await act(() => { |
| 164 | root.render(React.cloneElement(<Component>xyz</Component>, {})); |
| 165 | }); |
| 166 | }); |
| 167 | |
| 168 | it('should accept children as rest arguments', () => { |
| 169 | class Component extends React.Component { |
| 170 | render() { |
| 171 | return null; |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | const clone = React.cloneElement( |
| 176 | <Component>xyz</Component>, |
| 177 | {children: <Component />}, |
| 178 | <div />, |
| 179 | <span />, |
| 180 | ); |
| 181 | |
| 182 | expect(clone.props.children).toEqual([<div />, <span />]); |
| 183 | }); |
| 184 | |
| 185 | it('should override children if undefined is provided as an argument', () => { |
| 186 | const element = React.createElement( |
| 187 | ComponentClass, |
| 188 | { |
| 189 | children: 'text', |
| 190 | }, |
| 191 | undefined, |
| 192 | ); |
| 193 | expect(element.props.children).toBe(undefined); |
| 194 | |
| 195 | const element2 = React.cloneElement( |
| 196 | React.createElement(ComponentClass, { |
| 197 | children: 'text', |
| 198 | }), |
| 199 | {}, |
| 200 | undefined, |
| 201 | ); |
| 202 | expect(element2.props.children).toBe(undefined); |
| 203 | }); |
| 204 | |
| 205 | it('should support keys and refs', async () => { |
| 206 | let component; |
| 207 | class Parent extends React.Component { |
| 208 | xyzRef = React.createRef(); |
| 209 | |
| 210 | render() { |
| 211 | const clone = React.cloneElement(this.props.children, { |
| 212 | key: 'xyz', |
| 213 | ref: this.xyzRef, |
| 214 | }); |
| 215 | expect(clone.key).toBe('xyz'); |
| 216 | expect(clone.props.ref).toBe(this.xyzRef); |
| 217 | return <div>{clone}</div>; |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | class Grandparent extends React.Component { |
| 222 | parentRef = React.createRef(); |
| 223 | |
| 224 | componentDidMount() { |
| 225 | component = this; |
| 226 | } |
| 227 | |
| 228 | render() { |
| 229 | return ( |
| 230 | <Parent ref={this.parentRef}> |
| 231 | <span key="abc" /> |
| 232 | </Parent> |
| 233 | ); |
| 234 | } |
| 235 | } |
| 236 | |
| 237 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 238 | await act(() => root.render(<Grandparent />)); |
| 239 | expect(component.parentRef.current.xyzRef.current.tagName).toBe('SPAN'); |
| 240 | }); |
| 241 | |
| 242 | it('should steal the ref if a new ref is specified', async () => { |
| 243 | let component; |
| 244 | class Parent extends React.Component { |
| 245 | xyzRef = React.createRef(); |
| 246 | |
| 247 | render() { |
| 248 | const clone = React.cloneElement(this.props.children, { |
| 249 | ref: this.xyzRef, |
| 250 | }); |
| 251 | return <div>{clone}</div>; |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | class Grandparent extends React.Component { |
| 256 | parentRef = React.createRef(); |
| 257 | childRef = React.createRef(); |
| 258 | |
| 259 | componentDidMount() { |
| 260 | component = this; |
| 261 | } |
| 262 | |
| 263 | render() { |
| 264 | return ( |
| 265 | <Parent ref={this.parentRef}> |
| 266 | <span ref={this.childRef} /> |
| 267 | </Parent> |
| 268 | ); |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 273 | await act(() => root.render(<Grandparent />)); |
| 274 | expect(component.childRef).toEqual({current: null}); |
| 275 | expect(component.parentRef.current.xyzRef.current.tagName).toBe('SPAN'); |
| 276 | }); |
| 277 | |
| 278 | it('should overwrite props', async () => { |
| 279 | class Component extends React.Component { |
| 280 | render() { |
| 281 | expect(this.props.myprop).toBe('xyz'); |
| 282 | return <div />; |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 287 | await act(() => |
| 288 | root.render( |
| 289 | React.cloneElement(<Component myprop="abc" />, {myprop: 'xyz'}), |
| 290 | ), |
| 291 | ); |
| 292 | }); |
| 293 | |
| 294 | it('warns for keys for arrays of elements in rest args', async () => { |
| 295 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 296 | await act(() => { |
| 297 | root.render(React.cloneElement(<div />, null, [<div />, <div />])); |
| 298 | }); |
| 299 | assertConsoleErrorDev([ |
| 300 | 'Each child in a list should have a unique "key" prop.\n\n' + |
| 301 | 'Check the top-level render call using <div>. See https://react.dev/link/warning-keys for more information.\n' + |
| 302 | ' in div (at **)', |
| 303 | ]); |
| 304 | }); |
| 305 | |
| 306 | it('does not warns for arrays of elements with keys', async () => { |
| 307 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 308 | await act(() => { |
| 309 | root.render( |
| 310 | React.cloneElement(<div />, null, [<div key="#1" />, <div key="#2" />]), |
| 311 | ); |
| 312 | }); |
| 313 | }); |
| 314 | |
| 315 | it('does not warn when the element is directly in rest args', async () => { |
| 316 | const root = ReactDOMClient.createRoot(document.createElement('div')); |
| 317 | await act(() => { |
| 318 | root.render(React.cloneElement(<div />, null, <div />, <div />)); |
| 319 | }); |
| 320 | }); |
| 321 | |
| 322 | it('does not warn when the array contains a non-element', () => { |
| 323 | React.cloneElement(<div />, null, [{}, {}]); |
| 324 | }); |
| 325 | |
| 326 | it('should ignore key and ref warning getters', () => { |
| 327 | const elementA = React.createElement('div'); |
| 328 | const elementB = React.cloneElement(elementA, elementA.props); |
| 329 | expect(elementB.key).toBe(null); |
| 330 | expect(elementB.ref).toBe(null); |
| 331 | }); |
| 332 | |
| 333 | it('should ignore undefined key and ref', () => { |
| 334 | const element = React.createElement(ComponentClass, { |
| 335 | key: '12', |
| 336 | ref: '34', |
| 337 | foo: '56', |
| 338 | }); |
| 339 | const props = { |
| 340 | key: undefined, |
| 341 | ref: undefined, |
| 342 | foo: 'ef', |
| 343 | }; |
| 344 | const clone = React.cloneElement(element, props); |
| 345 | expect(clone.type).toBe(ComponentClass); |
| 346 | expect(clone.key).toBe('12'); |
| 347 | expect(clone.props.ref).toBe('34'); |
| 348 | expect(clone.ref).toBe('34'); |
| 349 | assertConsoleErrorDev([ |
| 350 | 'Accessing element.ref was removed in React 19. ref is now a ' + |
| 351 | 'regular prop. It will be removed from the JSX Element ' + |
| 352 | 'type in a future release.', |
| 353 | ]); |
| 354 | expect(clone.props).toEqual({foo: 'ef', ref: '34'}); |
| 355 | if (__DEV__) { |
| 356 | expect(Object.isFrozen(element)).toBe(true); |
| 357 | expect(Object.isFrozen(element.props)).toBe(true); |
| 358 | } |
| 359 | }); |
| 360 | |
| 361 | it('should extract null key and ref', () => { |
| 362 | const element = React.createElement(ComponentClass, { |
| 363 | key: '12', |
| 364 | ref: '34', |
| 365 | foo: '56', |
| 366 | }); |
| 367 | const props = { |
| 368 | key: null, |
| 369 | ref: null, |
| 370 | foo: 'ef', |
| 371 | }; |
| 372 | const clone = React.cloneElement(element, props); |
| 373 | expect(clone.type).toBe(ComponentClass); |
| 374 | expect(clone.key).toBe('null'); |
| 375 | expect(clone.ref).toBe(null); |
| 376 | expect(clone.props).toEqual({foo: 'ef', ref: null}); |
| 377 | if (__DEV__) { |
| 378 | expect(Object.isFrozen(element)).toBe(true); |
| 379 | expect(Object.isFrozen(element.props)).toBe(true); |
| 380 | } |
| 381 | }); |
| 382 | |
| 383 | it('throws an error if passed null', () => { |
| 384 | const element = null; |
| 385 | expect(() => React.cloneElement(element)).toThrow( |
| 386 | 'The argument must be a React element, but you passed null.', |
| 387 | ); |
| 388 | }); |
| 389 | |
| 390 | it('throws an error if passed undefined', () => { |
| 391 | let element; |
| 392 | expect(() => React.cloneElement(element)).toThrow( |
| 393 | 'The argument must be a React element, but you passed undefined.', |
| 394 | ); |
| 395 | }); |
| 396 | }); |