copyToClipboard

1/**
2 * Copies text to the system clipboard.
3 *
4 * @param text - The text to copy.
5 * @returns A promise that resolves if the copy is successful.
6 */
7export async function copyToClipboard(text: string): Promise<void> {
8  if (navigator.clipboard && navigator.clipboard.writeText) {
9    return navigator.clipboard.writeText(text);
10  }
11
12  // Fallback for older browsers
13  const textarea = document.createElement('textarea');
14  textarea.value = text;
15  textarea.setAttribute('readonly', '');
16  textarea.style.position = 'absolute';
17  textarea.style.left = '-9999px';
18
19  document.body.appendChild(textarea);
20  textarea.select();
21
22  try {
23    document.execCommand('copy');
24  } finally {
25    document.body.removeChild(textarea);
26  }
27}

1beforeEach(() => {
2  jest.restoreAllMocks();
3});
4
5test('uses navigator.clipboard if available', async () => {
6  const mockWriteText = jest.fn().mockResolvedValue(undefined);
7  Object.assign(navigator, {
8    clipboard: {
9      writeText: mockWriteText,
10    },
11  });
12
13  await copyToClipboard('Hello');
14  expect(mockWriteText).toHaveBeenCalledWith('Hello');
15});
16
17test('falls back to execCommand if clipboard API not available', async () => {
18  delete (navigator as any).clipboard;
19
20  const execCommandSpy = jest
21    .spyOn(document, 'execCommand')
22    .mockImplementation(() => true);
23
24  const appendSpy = jest.spyOn(document.body, 'appendChild');
25  const removeSpy = jest.spyOn(document.body, 'removeChild');
26
27  await copyToClipboard('Fallback');
28
29  expect(execCommandSpy).toHaveBeenCalledWith('copy');
30  expect(appendSpy).toHaveBeenCalled();
31  expect(removeSpy).toHaveBeenCalled();
32});