What

It is a matcher collection which is a further extension of jest-extended and is recommended to be used together with jest-extended.

Installation

With npm:

npm i --save-dev jest-extended-plus

With yarn:

yarn add -D jest-extended-plus

Setup

Note that jest-extended-plus only supports Jest version 24 and newer.

// ./testSetup.js

// add all jest-extended-plus matchers
import * as matchers from 'jest-extended-plus'
expect.extend(matchers)

// or just add specific matchers
import { toEqualOneOf } from 'jest-extended-plus'
expect.extend({ toEqualOneOf })

Add your setup script to your Jest setupFilesAfterEnv configuration. See for help

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

To automatically extend expect with all matchers, you can use

"jest": {
  "setupFilesAfterEnv": ["jest-extended-plus/all"]
}

Typescript

If your editor does not recognise the custom jest-extended-plus matchers, add a global.d.ts file to your project with:

import 'jest-extended-plus'

You must update your tsconfig.json to include the new global.d.ts file in the files property like so:

{
  "compilerOptions": {
    ...
  },
  ...
  "files": ["global.d.ts"]
}

Also note that when adding this for the first time this affects which files are compiled by the TypeScript compiler and you might need to add the include property as well. See the TypeScript docs for more details.

If the above import syntax does not work, replace it with the following:

/// <reference types="jest-extended-plus" />

API

.toEqualOneOf([members])

Use .toEqualOneOf when checking if a value equal to a member of a given Array.

test('passes when value is in given array', () => {
  expect(1).toEqualOneOf([expect.any(Number), null])
  expect(undefined).not.toEqualOneOf([expect.any(Number), null])
})

.toBeNumberOrNull()

Use .toBeNumberOrNull when checking if a value is a number or null.

test('passes when value is a number or null', () => {
  expect(0).toBeNumberOrNull()
  expect(null).toBeNumberOrNull()
  expect(undefined).not.toBeNumberOrNull()
})

.toBeStringOrNull([members])

Use .toBeStringOrNull when checking if a value is a string or null.

test('passes when value is a string or null', () => {
  expect('').toBeStringOrNull()
  expect(null).toBeStringOrNull()
  expect(true).not.toBeStringOrNull()
})

Contributing

Contributions, issues and feature requests are welcome!
Feel free to check issues.

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License

Copyright © 2021-present TomokiMiyauci.

Released under the MIT license