jest-fs-snapshot ·

Jest matcher for filesystem snapshotting.

Table of Contents

• Installation
• Getting Started
• API
  • toMatchFilesystemSnapshot
• Credits

Installation

1yarn add jest-fs-snapshot

Getting Started

1. Extend Jest's expect

1import { toMatchFilesystemSnapshot } from 'jest-fs-snapshot';
2
3expect.extend({ toMatchFilesystemSnapshot });

2. Use it in your tests!

1test('if build directory matches snapshot', () => {
2  const pathToBuildDir = path.resolve(process.cwd(), '.build');
3  expect(pathToBuildDir).toMatchFilesystemSnapshot();
4});

This will create a __fs_snapshots__ folder next to your test file with a snapshot file. On next runs it will chech if the snapshot against the source directory and with throw on mismatches.

API

.toMatchFilesystemSnapshot([pathToSnapshot, options])

Arguments

1. pathToSnapshot (String): An optional full path to a snapshot file.
2. options (Object): An optional object with additional configurations.
   1. customCompare ({check: Function, compare: Function}[]): Any custom compare function will be applied only if the check method returns true. If multiple checks return true, the first hit will be used.

Example

1const diff = require('jest-diff');
2
3const snapshotOptions = {
4  customCompare: [
5    {
6      check: path => path.endsWith('package.json'),
7      compare: (actualBuffer, expectedBuffer) => {
8        const actual = JSON.parse(actualBuffer);
9        const expected = JSON.parse(expectedBuffer);
10
11        // we want to ignore the peerModules
12        delete actual.peerModules;
13        delete expected.peerModules;
14
15        return diff(actual, expected);
16      },
17    },
18    {
19      // test.js files will be ignored
20      check: path => path.endsWith('.test.js'),
21      compare: () => true,
22    },
23  ],
24};
25
26describe('...', () => {
27  it('...', () => {
28    /**
29     * ...
30     */
31    expect(pathToBuildDir).toMatchFilesystemSnapshot(undefined, snapshotOptions);
32  });
33});

Credits

Many files for encodings fixture have been taken from https://github.com/mbbill/fencview.

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License

This package is released using the MIT license. For more information see the license file.