@sap-ux/jest-file-matchers

Library of jest matchers

Installation

Npm npm install --save @sap-ux/jest-file-matchers

Yarn yarn add @sap-ux/jest-file-matchers

Pnpm pnpm add @sap-ux/jest-file-matchers

Configuration

There are various ways of making the matchers available in your tests.

1. Setup code in a single file testSetup.[js|ts]:

// ./testSetup.[js|ts]

// Add all the matchers
import * as matchers from '@sap-ux/jest-file-matchers';
expect.extend(matchers);

// Or just add specific matchers
import { toMatchFolder } from '@sap-ux/jest-file-matchers';
expect.extend({ toMatchFolder });

Add the file to your jest config file:

"jest": {
  "setupFilesAfterEnv": ["./testSetup.js"]
}

2. Call setup code from @sap-ux/jest-file-matchers:

"jest": {
  "setupFilesAfterEnv": ["@sap-ux/jest-file-matchers/dist/setup"]
}

This will make all the matchers available in all your tests.

3. Extend the expect object only in the files where the matchers are needed:

import { toMatchFolder } from  '@sap/ux-jest-matcher';

expect.extend({ toMatchFolder });

Option 2 is the easiest.

Usage

toMatchFolder()

Import the matchers to get the type definitions loaded:

import '@sap-ux/jest-file-matchers';

expect(folderA).toMatchFolder(snapShotFolderA);

This will perform snapshot tests of the files under folderA. snapShotFolderA contains snapshots of the files as seperate files. Both folders need to be full paths, to be unambiguous.

Use with .not:

import '@sap-ux/jest-file-matchers';

expect(folderA).not.toMatchFolder(snapShotFolderA);

toMatchFolder accepts optional include/exclude filters. These filters are basic minimatch glob patterns. Exclude filters have a higher precedence over include filters, i.e if a file path matches both include and exclude glob patterns, it will be excluded.

Example:

//  Only include Javascript files
expect(folderA).not.toMatchFolder(snapShotFolderA, { include: ['**/.js'] });

//  Only include Javascript files & HTML, exclude setup.js
expect(folderA).not.toMatchFolder(snapShotFolderA, { include: ['**/.js', '**.htm?(l)'], exclude: ['**/setup.js'] });

//  Ignore .DS_Store files
expect(folderA).not.toMatchFolder(snapShotFolderA, { exclude: ['**/.DS_Store'] });

//  Ignore everything in the dist folder
expect(folderA).not.toMatchFolder(snapShotFolderA, { exclude: ['**/dist/**'] });

toMatchFolder uses two other matchers internally. They are also available to be used on their own:

• toContainAllFilesIn: asserts that the received folder contains all the files the expected folder (matches on filenames only)
• toMatchFilesIn: asserts that the file contents match the contents of files with the same relative path wrt the snapshot folder.

These two matchers have an identical function signature.

Update snapshots

Pass -u or --update to update the snapshot folder. Please use this with care and verify the contents are actually correct.

Keywords

SAP Fiori Tools