feat: support experimental doc entries
- Params/options/members are marked as experimental in the docs.
- `experimental.d.ts` is generated that contains all types and
includes experimental features.
- `experimental.d.ts` is references in our tests so that we
can test experimental features.
- `fonts` option is restored as experimental.
- Always show a fixture that was running during timeout.
- Give custom titles to built-in fixtures.
- Specify setup/teardown fixture phase in the message.
- Split connect vs launch browser fixtures for better naming.
Example timeout message:
```log
Timeout of 2000ms exceeded while running fixture "built-in playwright configuration" teardown.
```
Firefox has a bug: calling `node.focus()` does make the node focused,
but some internal "current contenteditable node" is not changed.
Blurring the previous one and focusing the new one helps.
This is a speculative fix to leftover tmp directories.
When users issues SIGINT twice, we enter `gracefullyClose()`
twice, and shortcut the second time. It turns out, we do
not wait for directories removal.
Note: it is unknown how often we reach this codepath in practice.
A few changes:
- `Matchers<R, T>` now carries both return and argument type.
- Based on the argument type, we apply playwright-specific Page/Locator matchers.
- Return type is usually void, unless wrapped with `expect.resolves`,
`expect.rejects` or `expect.poll()`.
- To preserve compatibility with any extended types in the wild,
argument type is optional.
If you typo'd an `expect` property, you got a cryptic error message:
```
Uncaught TypeError: Cannot create proxy with a non-object as target or handler
```
Now we get this nice friendly message:
```
1) a.spec.ts:6:9 › explodes ======================================================================
Error: expect: Property 'toBeLessThen' not found.
Did you mean 'toBeLessThan'?
See https://playwright.dev/docs/test-assertions for available options and documentation.
5 | const { test } = pwt;
6 | test('explodes', () => {
> 7 | expect.soft(1).toBeLessThen();
| ^
8 | });
9 |
```
Fixes#13218
