Hello intenta realizar una prueba de una función, pero recibe este error relacionado.

 TypeError: Cannot read properties of undefined (reading 'setFocus') 81 | this.lastFocusableElement = this.focusableElements[this.focusableElements.length - 1]; 82 | > 83 | this.firstFocusableElement.setFocus(); | ^ 84 | } 85 | 86 | private clearFocusableElements(): void { at HTMLElement.setFocus (packages/modal/src/modal.ts:83:40) at HTMLElement.open (packages/modal/src/modal.ts:63:10) at Object.<anonymous> (packages/modal/src/modal.test.ts:102:14)

mi funcion

 private setFocus(): void { this.clearFocusableElements(); this.findFocusableElements(this.querySelectorAll('*')); this.firstFocusableElement = this.modalElement.querySelector('.modal-close'); this.lastFocusableElement = this.focusableElements[this.focusableElements.length - 1]; this.firstFocusableElement.setFocus(); }