1. Fixtures defined in test.extend() can now have `{ option: true }` configuration that makes them overridable in the config. Options support all other properties of fixtures - value/function, scope, auto.
```
const test = base.extend<MyOptions>({
foo: ['default', { option: true }],
});
```
2. test.declare() and project.define are removed.
3. project.use applies overrides to default option values and nothing else. Any test.extend() and test.use() calls take priority over config options.
Required user changes: if someone used to define fixture options with test.extend(), overriding them in config will stop working. The solution is to add `{ option: true }`.
```
// Old code
export const test = base.extend<{ myOption: number, myFixture: number }>({
myOption: 123,
myFixture: ({ myOption }, use) => use(2 * myOption),
});
// New code
export const test = base.extend<{ myOption: number, myFixture: number }>({
myOption: [123, { option: true }],
myFixture: ({ myOption }, use) => use(2 * myOption),
});
```
When fixture value `R` is a function, TypeScript sometimes confuses
function `R` and function `async ({}, use) => {}`. This leads to
`any` types in the latter because it could be either of the functions
as TS thinks.
The solution is to only accept the second syntax, assuming that noone
passes fixture value that is a function as is:
```js
// This will stop working.
test.extend<{ foo: (x: number) => number }>({
foo: x => 2 * x,
});
// This will get inferred types and autocomplete.
test.extend<{ foo: (x: number) => number }>({
foo: async ({}, use) => {
await use(x => 2 * x);
},
});
```
- Each overload, e.g. for `page.evaluate`, shows a nice autocomplete doc,
not only the first one.
- We can have multiple overloads directly on the docs page, e.g.
`test.skip(title, fn)` and `test.skip(condition, description)`.
These overloads are internally named `Test.skip#1` and all aliased
to `test.skip`.
- Uses some auto fixtures to set default options and instrumentation on BrowserType.
- Moves screenshot, trace and video to worker-scoped fixtures.
- Throws in page/context when used from beforeAll/afterAll.
- Plumbs around BrowserType to be accessible from Browser and BrowserContext.
Each hook gets its own test scope. This is not too useful for
object fixtures like `page` (although one can use a page in
`beforeAll` to save storage state), but much more useful for option
fixtures like `viewport`.
