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https://github.com/satya164/jest-file-snapshot
Jest matcher to write snapshots to a separate file instead of the default snapshot file used by Jest
https://github.com/satya164/jest-file-snapshot
hacktoberfest jest snapshot-testing testing
Last synced: 6 days ago
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Jest matcher to write snapshots to a separate file instead of the default snapshot file used by Jest
- Host: GitHub
- URL: https://github.com/satya164/jest-file-snapshot
- Owner: satya164
- Created: 2018-09-29T21:44:37.000Z (about 6 years ago)
- Default Branch: main
- Last Pushed: 2024-07-10T19:51:02.000Z (4 months ago)
- Last Synced: 2024-10-26T17:13:59.340Z (12 days ago)
- Topics: hacktoberfest, jest, snapshot-testing, testing
- Language: JavaScript
- Homepage:
- Size: 2.29 MB
- Stars: 40
- Watchers: 3
- Forks: 13
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
- awesome-jest - jest-file-snapshot
README
# jest-file-snapshot
[![Build Status][build-badge]][build]
[![Code Coverage][coverage-badge]][coverage]
[![MIT License][license-badge]][license]
[![Version][version-badge]][package]
Jest matcher to write snapshots to a separate file instead of the default snapshot file used by Jest. Writing a snapshot to a separate file means you have proper syntax highlighting in the output file, and better readability without those pesky escape characters. It's also useful if you have binary content.
## Installation
```sh
npm install --save-dev jest-file-snapshot
```
or
```sh
yarn add --dev jest-file-snapshot
```
## Usage
Extend Jest's `expect`:
```js
import { toMatchFile } from 'jest-file-snapshot';
expect.extend({ toMatchFile });
```
Then use it in your tests:
```js
it('matches content of file on disk', () => {
expect(content).toMatchFile();
});
```
The content passed can be of type `string` or a `Buffer`. The comparison be done using `Buffer.equals()` instead of `===` if a `Buffer` is passed.
The matcher takes two optional arguments:
- `filepath`: path to the file whose content should be matched, e.g. `expect(content).toMatchFile(path.join(__dirname, 'output.md'))`
- `options`: additional options object for the matcher, with following properties:
- `diff`: options for [`jest-diff`](https://github.com/facebook/jest/tree/master/packages/jest-diff)
- `fileExtension`: optional file extension to use for the snapshot file.
You should also [exclude the output files from Jest's watcher](https://jestjs.io/docs/en/configuration#watchpathignorepatterns-arraystring) so that updating the snapshot doesn't re-run the tests again.
For example, by default `toMatchFile` uses a folder named `__file_snapshots__` which you can exclude by adding the following under the `jest` key in `package.json`:
```json
"watchPathIgnorePatterns": [
"__file_snapshots__"
]
```
## Credits
- [jest-image-snapshot](https://github.com/americanexpress/jest-image-snapshot)
## Contributing
Make sure your code passes the unit tests, ESLint and TypeScript. Run the following to verify:
```sh
yarn test
yarn lint
yarn typescript
```
To fix formatting errors, run the following:
```sh
yarn lint -- --fix
```
[build-badge]: https://img.shields.io/circleci/project/github/satya164/jest-file-snapshot/main.svg?style=flat-square
[build]: https://circleci.com/gh/satya164/jest-file-snapshot
[coverage-badge]: https://img.shields.io/codecov/c/github/satya164/jest-file-snapshot.svg?style=flat-square
[coverage]: https://codecov.io/github/satya164/jest-file-snapshot
[license-badge]: https://img.shields.io/npm/l/jest-file-snapshot.svg?style=flat-square
[license]: https://opensource.org/licenses/MIT
[version-badge]: https://img.shields.io/npm/v/jest-file-snapshot.svg?style=flat-square
[package]: https://www.npmjs.com/package/jest-file-snapshot