The `screenshotsDir` option controls the expectation storage
for `toHaveScreenshot()` function.
The new expectation management for screenshots has the following
key properties:
- All screenshots are stored in a single folder called `screenshotsDir`.
- Screenshot names **do not** respect `snapshotDir` and `snapshotSuffix`
configurations.
- `screenshotsDir` is configurable per project. This way a "smoke tests"
project can re-use screenshots from "all tests" project.
- Host platform is a top-level folder.
For example, given the following config:
```js
// playwright.config.ts
module.exports = {
projects: [
{ name: 'Mobile Safari' },
{ name: 'Desktop Chrome' },
],
};
```
And the following test structure:
```
smoke-tests/
└── basic.spec.ts
```
Will result in the following screenshots folder structure by default:
```
__screenshots__/
└── darwin/
├── Mobile Safari/
│ └── smoke-tests/
│ └── basic.spec.ts/
│ └── screenshot-expectation.png
└── Desktop Chrome/
└── smoke-tests/
└── basic.spec.ts/
└── screenshot-expectation.png
```
This patch adds additional options to `toMatchSnapshot` method:
- `pixelCount` - acceptable number of pixels that differ to still
consider images equal. Unset by default.
- `pixelRatio` - acceptable ratio of all image pixels (from 0 to 1) that differ to still
consider images equal. Unset by default.
Fixes#12167, #10219
