https://github.com/jaydenseric/snapshot-assertion

Asserts a string matches a snapshot saved in a file. An environment variable can be used to save rather than assert snapshots.
https://github.com/jaydenseric/snapshot-assertion

esm maintained mjs node npm typescript

Last synced: 14 days ago
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Asserts a string matches a snapshot saved in a file. An environment variable can be used to save rather than assert snapshots.

• Host: GitHub
• URL: https://github.com/jaydenseric/snapshot-assertion
• Owner: jaydenseric
• License: mit
• Created: 2020-01-07T12:26:26.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2023-04-25T22:05:24.000Z (over 1 year ago)
• Last Synced: 2024-10-04T13:44:07.139Z (about 1 month ago)
• Topics: esm, maintained, mjs, node, npm, typescript
• Language: JavaScript
• Homepage: https://npm.im/snapshot-assertion
• Size: 60.5 KB
• Stars: 16
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md
  • Changelog: changelog.md
  • Funding: .github/funding.yml
  • License: license.md

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README

        
# snapshot-assertion

Asserts a string matches a snapshot saved in a file. An environment variable can be used to save rather than assert snapshots.

## Installation

To install [`snapshot-assertion`](https://npm.im/snapshot-assertion) with [npm](https://npmjs.com/get-npm), run:

```sh

npm install snapshot-assertion --save-dev

```

Then, import and use the function [`assertSnapshot`](./assertSnapshot.mjs).

## Examples

A snapshot assertion in a [`test-director`](https://npm.im/test-director) test:

```js

import fetch from "node-fetch";

import assertSnapshot from "snapshot-assertion";

import TestDirector from "test-director";

const tests = new TestDirector();

tests.add("Get a todo.", async () => {

  const response = await fetch("https://jsonplaceholder.typicode.com/todos/1");

  await assertSnapshot(await response.json(), "snapshots/todo.json");

});

tests.run();

```

Using the `SAVE_SNAPSHOTS` environment variable to save snapshots when running a package script:

```sh

SAVE_SNAPSHOTS=1 npm run test

```

## Requirements

Supported runtime environments:

- [Node.js](https://nodejs.org) versions `^16.9.0 || >= 18.0.0`.

Projects must configure [TypeScript](https://typescriptlang.org) to use types from the ECMAScript modules that have a `// @ts-check` comment:

- [`compilerOptions.allowJs`](https://typescriptlang.org/tsconfig#allowJs) should be `true`.

- [`compilerOptions.maxNodeModuleJsDepth`](https://typescriptlang.org/tsconfig#maxNodeModuleJsDepth) should be reasonably large, e.g. `10`.

- [`compilerOptions.module`](https://typescriptlang.org/tsconfig#module) should be `"node16"` or `"nodenext"`.

## Exports

The [npm](https://npmjs.com) package [`snapshot-assertion`](https://npm.im/snapshot-assertion) features [optimal JavaScript module design](https://jaydenseric.com/blog/optimal-javascript-module-design). These ECMAScript modules are exported via the [`package.json`](./package.json) field [`exports`](https://nodejs.org/api/packages.html#exports):

- [`assertSnapshot.mjs`](./assertSnapshot.mjs)