https://github.com/btravers/pdf-snapshot
Jest matcher for visual regression testing of PDF documents
https://github.com/btravers/pdf-snapshot
canvas docker jest nodejs pdf pdfjs snapshot test testing trpc typescript visual-regression-testing
Last synced: 5 months ago
JSON representation
Jest matcher for visual regression testing of PDF documents
- Host: GitHub
- URL: https://github.com/btravers/pdf-snapshot
- Owner: btravers
- License: mit
- Created: 2022-09-26T19:28:14.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2023-07-18T12:23:01.000Z (almost 3 years ago)
- Last Synced: 2025-09-27T14:52:02.773Z (9 months ago)
- Topics: canvas, docker, jest, nodejs, pdf, pdfjs, snapshot, test, testing, trpc, typescript, visual-regression-testing
- Language: TypeScript
- Homepage:
- Size: 184 KB
- Stars: 11
- Watchers: 1
- Forks: 1
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# PDF Snapshot
Jest matcher for visual regression testing of PDF documents.
Behaves just like [Jest snapshots](https://facebook.github.io/jest/docs/snapshot-testing.html) do.
Under the hood, it uses [pdf.js](https://github.com/mozilla/pdf.js) for conversion of a pdf to png.
In node, pdf.js depends on [canvas](https://github.com/Automattic/node-canvas).
Finally, the comparison is happening via [pixelmatch](https://github.com/mapbox/pixelmatch).
In order to be platform agnostic, the png conversion and png comparison is performed by a small server running aside, available as a [Docker image](https://hub.docker.com/r/btravers/pdf-snapshot) and communicating with Jest matcher using [tRCP](https://github.com/trpc/trpc).
## Usage
### Prerequisites
Before you begin, ensure you have met the following requirements:
- You have installed the latest version of Docker.
### Installation
First pull the Docker image of the main service.
```sh
docker pull btravers/pdf-snapshot
```
Then install Jest matcher in the dev dependencies of your project.
```sh
npm install --save-dev @btravers/pdf-snapshot-jest
```
Please note that Jest 28 is a peerDependency.
Declare `toMatchPdfSnapshot` matcher in your Jest configuration.
```json
"jest": {
"setupFilesAfterEnv": [
"@btravers/pdf-snapshot-jest/dist/toMatchPdfSnapshot"
]
}
```
If you are using **Typescript** add `import('@btravers/pdf-snapshot-jest/dist/toMatchPdfSnapshot');` to your typings.
### Invocation
Start the container with the main service.
```sh
docker run -d -p 3000:3000 btravers/pdf-snapshot
```
In your test, export `PDF_SNAPSHOT_SERVER_URL` environment variable in order to link Jest matcher with the service running in the container.
```js
process.env.PDF_SNAPSHOT_SERVER_URL = 'http://localhost:3000'
```
Now, all you have to do in your tests is pass a pdf content as Buffer.
```ts
const pdfBuffer = await fs.promise.readFile('path to your pdf');
describe('test pdf report visual regression', () => {
it('should match', () => expect(pdfBuffer).toMatchPdfSnapshot());
});
```
### Go further
You can rely on [testcontainers-node](https://github.com/testcontainers/testcontainers-node) and automate the container start before tests run.
## Credits
- [pdf-visual-diff](https://github.com/moshensky/pdf-visual-diff)
- [jest-image-snapshot](https://github.com/americanexpress/jest-image-snapshot)