chai-string

What is chai-string?

chai-string is an extension for the Chai assertion library that provides a set of string-specific assertions. It allows developers to write more readable and expressive tests for string values.

What are chai-string's main functionalities?

startsWith

Asserts that a string starts with a given substring.

const chai = require('chai');
const chaiString = require('chai-string');
chai.use(chaiString);
const expect = chai.expect;

expect('Hello, world!').to.startWith('Hello');

endsWith

Asserts that a string ends with a given substring.

const chai = require('chai');
const chaiString = require('chai-string');
chai.use(chaiString);
const expect = chai.expect;

expect('Hello, world!').to.endWith('world!');

contains

Asserts that a string contains a given substring.

const chai = require('chai');
const chaiString = require('chai-string');
chai.use(chaiString);
const expect = chai.expect;

expect('Hello, world!').to.contain('world');

equalIgnoreCase

Asserts that two strings are equal, ignoring case.

const chai = require('chai');
const chaiString = require('chai-string');
chai.use(chaiString);
const expect = chai.expect;

expect('Hello').to.equalIgnoreCase('hello');

singleLine

Asserts that a string is a single line (i.e., does not contain newline characters).

const chai = require('chai');
const chaiString = require('chai-string');
chai.use(chaiString);
const expect = chai.expect;

expect('Hello, world!').to.be.singleLine;

Other packages similar to chai-string

chai

Chai is a BDD / TDD assertion library for node and the browser that can be delightfully paired with any javascript testing framework. While chai-string extends Chai with string-specific assertions, Chai itself provides a more general set of assertions for various data types.

jest

Jest is a delightful JavaScript Testing Framework with a focus on simplicity. It includes built-in matchers for string assertions, such as `toMatch` for regex matching and `toContain` for substring checks. However, it does not provide as many specialized string assertions as chai-string.

should

Should is an expressive, readable, framework-agnostic assertion library. It provides some string-specific assertions like `startWith` and `endWith`, similar to chai-string, but it is not as focused on string assertions as chai-string.

README

chai-string

Matchers for chai to help with common string comparison assertions.

Usage

Browser

<script src="chai.js"></script>
<script src="chai-string.js"></script>

Server

var chai = require('chai');
chai.use(require('chai-string'));

Assertions

• startsWith/startWith
• endsWith/endWith
• equalIgnoreCase
• equalIgnoreSpaces
• containIgnoreSpaces
• singleLine
• reverseOf
• palindrome
• entriesCount
• indexOf

All assertions are defined for both the BDD and TDD syntax but some aliases exist to make the assertions look good with both styles.

var d1 = 'abcdef',
    d2 = 'abc';

d1.should.startWith.d2
expect(d1).to.startsWith(d2)
assert.startsWith(d1, d2)

startsWith/startWith

assert.startsWith('abcdef', 'abc');
expect('abcdef').to.startsWith('abc');
'abcdef'.should.startWith('abc');

endsWith/endWith

assert.endsWith('abcdef', 'def');
expect('abcdef').to.endsWith('def');
'abcdef'.should.endWith('def');

equalIgnoreCase

assert.equalIgnoreCase('abcdef', 'AbCdEf');
expect('abcdef').to.equalIgnoreCase('AbCdEf');

equalIgnoreSpaces

assert.equalIgnoreSpaces('abcdef', 'a\nb\tc\r d  ef');
expect('abcdef').to.equalIgnoreSpaces('a\nb\tc\r d  ef');

containIgnoreSpaces

assert.containIgnoreSpaces('abcdefgh', 'a\nb\tc\r d  ef');
expect('abcdefgh').to.containIgnoreSpaces('a\nb\tc\r d  ef');

containIgnoreCase

assert.containIgnoreCase('abcdefgh', 'AbcDefGH'); 
expect('abcdefgh').to.containIgnoreCase('AbcDefGH');
'abcdef'.should.containIgnoreCase('cDe');

singleLine

assert.singleLine('abcdef');
expect('abcdef').to.be.singleLine();

reverseOf

assert.reverseOf('abcdef', 'fedcba');
expect('abcdef').to.be.reverseOf('fedcba');

palindrome

assert.palindrome('abccba');
expect('abccba').to.be.palindrome();

entriesCount

assert.entriesCount('abcabd', 'ab', 2);
expect('abcabd').to.have.entriesCount('ab', 2);

indexOf

assert.indexOf('abcabd', 'ab', 0);
expect('abcabd').to.have.indexOf('ab', 0);

Thanks

Thanks to the chai-datetime module for giving me an idea for how to structure and test a chai plugin.