https://github.com/funny-bytes/chai-quantifiers

Array quantifier assertions for chai.
https://github.com/funny-bytes/chai-quantifiers

assertions chai unit-testing

Last synced: 5 months ago
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Array quantifier assertions for chai.

• Host: GitHub
• URL: https://github.com/funny-bytes/chai-quantifiers
• Owner: funny-bytes
• Created: 2018-02-22T18:12:14.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2024-02-26T14:55:28.000Z (over 2 years ago)
• Last Synced: 2025-09-24T09:50:10.599Z (9 months ago)
• Topics: assertions, chai, unit-testing
• Language: JavaScript
• Homepage:
• Size: 506 KB
• Stars: 5
• Watchers: 2
• Forks: 1
• Open Issues: 5
• Metadata Files:
  • Readme: README.md

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README

          
# chai-quantifiers

Array quantifier assertions for [Chai](http://chaijs.com/) assertion library.

![main workflow](https://github.com/funny-bytes/chai-quantifiers/actions/workflows/main.yml/badge.svg)

[![Coverage Status](https://coveralls.io/repos/github/funny-bytes/chai-quantifiers/badge.svg?branch=master)](https://coveralls.io/github/funny-bytes/chai-quantifiers?branch=master)

[![Maintainability](https://api.codeclimate.com/v1/badges/44fb4c780c3f36b0d04f/maintainability)](https://codeclimate.com/github/funny-bytes/chai-quantifiers/maintainability)

[![node](https://img.shields.io/node/v/chai-quantifiers.svg)]()

[![code style](https://img.shields.io/badge/code_style-airbnb-brightgreen.svg)](https://github.com/airbnb/javascript)

[![Types](https://img.shields.io/npm/types/chai-quantifiers.svg)](https://www.npmjs.com/package/chai-quantifiers)

[![License Status](http://img.shields.io/npm/l/chai-quantifiers.svg)]()

## Install

```bash

npm install --save-dev chai chai-quantifiers

```

## Usage

There are three assertions available, applicable to arrays.

* containAll -- Asserts that all array items are true in respect to a predicate.

* containOne -- Asserts that at least one array item is true in respect to a predicate.

* containExactlyOne -- Asserts that exactly one array item is true in respect to a predicate.

A quick example:

```javascript

const chai = require('chai');

const chaiQuantifiers = require('chai-quantifiers');

chai.use(chaiQuantifiers);

const { expect } = chai;

describe('chai-quantifiers', () => {

  it('containAll should be true if all items are true', () => {

    expect([0, 1, 2, 3]).to.containAll(item => item < 4);

  });

  it('containOne should be true if at least one item is true', () => {

    expect([0, 1, 2, 3]).to.containOne(item => item >= 2);

  });

  it('containExactlyOne should be true if exactly one item is true', () => {

    expect([0, 1, 2, 3]).to.containExactlyOne(item => item === 2);

  });

});

```

This module also includes types for *TypeScript*.