playwright/docs/src/api/class-snapshotassertions.md
Dmitry Gozman 603861c48d
fix: revert toMatchSnapshot deprecation (#27089)
- This reverts commit
8348f66107
landed in #26718.
- Update docs to point towards `toHaveScreenshot`.
2023-09-14 12:52:41 -07:00

104 lines
3.2 KiB
Markdown

# class: SnapshotAssertions
* since: v1.20
* langs: js
Playwright provides methods for comparing page and element screenshots with
expected values stored in files.
```js
expect(screenshot).toMatchSnapshot('landing-page.png');
```
## method: SnapshotAssertions.toMatchSnapshot#1
* since: v1.22
:::caution
To compare screenshots, use [`method: PageAssertions.toHaveScreenshot#1`] instead.
:::
Ensures that passed value, either a [string] or a [Buffer], matches the expected snapshot stored in the test snapshots directory.
**Usage**
```js
// Basic usage.
expect(await page.screenshot()).toMatchSnapshot('landing-page.png');
// Pass options to customize the snapshot comparison and have a generated name.
expect(await page.screenshot()).toMatchSnapshot('landing-page.png', {
maxDiffPixels: 27, // allow no more than 27 different pixels.
});
// Configure image matching threshold.
expect(await page.screenshot()).toMatchSnapshot('landing-page.png', { threshold: 0.3 });
// Bring some structure to your snapshot files by passing file path segments.
expect(await page.screenshot()).toMatchSnapshot(['landing', 'step2.png']);
expect(await page.screenshot()).toMatchSnapshot(['landing', 'step3.png']);
```
Learn more about [visual comparisons](../test-snapshots.md).
Note that matching snapshots only work with Playwright test runner.
### param: SnapshotAssertions.toMatchSnapshot#1.name
* since: v1.22
- `name` <[string]|[Array]<[string]>>
Snapshot name.
### option: SnapshotAssertions.toMatchSnapshot#1.maxDiffPixels = %%-assertions-max-diff-pixels-%%
* since: v1.22
### option: SnapshotAssertions.toMatchSnapshot#1.maxDiffPixelRatio = %%-assertions-max-diff-pixel-ratio-%%
* since: v1.22
### option: SnapshotAssertions.toMatchSnapshot#1.threshold = %%-assertions-threshold-%%
* since: v1.22
## method: SnapshotAssertions.toMatchSnapshot#2
* since: v1.22
:::caution
To compare screenshots, use [`method: PageAssertions.toHaveScreenshot#2`] instead.
:::
Ensures that passed value, either a [string] or a [Buffer], matches the expected snapshot stored in the test snapshots directory.
**Usage**
```js
// Basic usage and the file name is derived from the test name.
expect(await page.screenshot()).toMatchSnapshot();
// Pass options to customize the snapshot comparison and have a generated name.
expect(await page.screenshot()).toMatchSnapshot({
maxDiffPixels: 27, // allow no more than 27 different pixels.
});
// Configure image matching threshold and snapshot name.
expect(await page.screenshot()).toMatchSnapshot({
name: 'landing-page.png',
threshold: 0.3,
});
```
Learn more about [visual comparisons](../test-snapshots.md).
Note that matching snapshots only work with Playwright test runner.
### option: SnapshotAssertions.toMatchSnapshot#2.maxDiffPixels = %%-assertions-max-diff-pixels-%%
* since: v1.22
### option: SnapshotAssertions.toMatchSnapshot#2.maxDiffPixelRatio = %%-assertions-max-diff-pixel-ratio-%%
* since: v1.22
### option: SnapshotAssertions.toMatchSnapshot#2.name
* since: v1.22
- `name` <[string]|[Array]<[string]>>
Snapshot name. If not passed, the test name and ordinals are used when called multiple times.
### option: SnapshotAssertions.toMatchSnapshot#2.threshold = %%-assertions-threshold-%%
* since: v1.22