Chai Things

0.2.0 verified Sat Apr 25 auth: no javascript deprecated

Chai Things (v0.2.0, unmaintained since 2015) extends Chai assertion library with array element matchers like `include.something.that`, `all`, and `none`. Allows deep equality, property, and nested assertions on arrays. Last updated on npm in 2016; no releases for 9+ years. Use with Chai v4.x but may have compatibility issues. Alternative: use native Chai `members` matcher with deep equality or Lodash`_.some`/_.every.

Common errors

error TypeError: Cannot read property 'use' of undefined ↓

cause chai is not imported or chai.should() not called.

fix

Ensure you have required chai and called chai.should() or chai.expect before using chai-things.

error AssertionError: expected [] to include something that deeply equals ... ↓

cause Using something matcher on an empty array; no element matches.

fix

Check that array is not empty or use include.something.that on non-empty arrays.

error chai-things: Error: cannot call include.something.that on non-array value ↓

cause Attempting to use include.something.that on a non-array object.

fix

Ensure the value being tested is an Array.

Warnings

deprecated Package has not been updated since 2016. It may not work with Chai 5.x or newer. ↓

fix Consider using chai.assert.deepInclude or other native Chai methods, or migrate to a maintained library.

gotcha Cannot be used with ESM imports directly; only CommonJS require works reliably. ↓

fix Use dynamic import: const chaiThings = (await import('chai-things')).default;

breaking In Chai 4.x, 'should' interface requires chai.should() call before chai.use(require('chai-things')). ↓

fix Always call chai.should() earlier or use chai.expect with chai-things.

gotcha The 'all' and 'none' matchers treat empty arrays as vacuously true (all matches everything, none matches nothing). ↓

fix Add explicit length check if needed: arr.should.have.length.gt(0).and.all.satisfy(...).

Install

npm install chai-things

yarn add chai-things

pnpm add chai-things

Imports

default

wrong

const chaiThings = require('chai-things'); chai.use(chaiThings);

correct

import chaiThings from 'chai-things'; chai.use(chaiThings);

CommonJS require works but is not recommended for ESM projects. The package does not export named symbols.

chai-things
wrong
```
import { something } from 'chai-things';
```
correct
```
import 'chai-things'; // side-effect import when used via chai.should()
```
chai-things does not export named symbols; it only registers Chai plugins and extends the assertion chain.
Plugin usage
wrong
```
const { Plugin } = require('chai-things');
```
correct
```
chai.use(require('chai-things')); // CommonJS
```
chai-things must be used with chai.use(). There is no default export or Plugin class.

Quickstart

Install chai-things, register with chai, and use include.something.that / all / none assertions on arrays.

const chai = require('chai');
chai.should();
chai.use(require('chai-things'));

// Example:
const items = [{ a: 1 }, { b: 2 }];
items.should.include.something.that.deep.equals({ b: 2 });
// passes

items.should.all.have.property('a');
// fails because { b: 2 } does not have property 'a'

items.should.not.include.something.that.deep.equals({ c: 3 });
// passes