Download Chai v5.1.1

Should

chai.should();

foo.should.be.a('string');
foo.should.equal('bar');
foo.should.have.lengthOf(3);
tea.should.have.property('flavors')
  .with.lengthOf(3);
                

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Expect

var expect = chai.expect;

expect(foo).to.be.a('string');
expect(foo).to.equal('bar');
expect(foo).to.have.lengthOf(3);
expect(tea).to.have.property('flavors')
  .with.lengthOf(3);
                

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Assert

var assert = chai.assert;

assert.typeOf(foo, 'string');
assert.equal(foo, 'bar');
assert.lengthOf(foo, 3)
assert.property(tea, 'flavors');
assert.lengthOf(tea.flavors, 3);
                

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Plugins extend Chai's assertions to new contexts such as vendor integration & object construction. Developers can build their own plugins to share with community or use the plugin pattern to DRY up existing tests.

chai-webdriver

Learn More & Install →

Featured Plugin

Create expressive integration tests with chai and selenium-webdriver.

                chai.use(chaiWebdriver(driver));
driver.get('http://chaijs.com/');
expect('nav h1').dom.to.contain.text('Chai');
expect('#node .button').dom.to.have.style('float', 'left');

                

Custom Plugins

Browse our growing directory of custom plugins & vendor integrations to find the best tool for your needs.

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Develop Plugins

Chai has an extensive utility belt for plugin developers. Learn how to build your plugins & share.

Plugin Guide→

 

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Chai is hosted on GitHub. Have a suggestion or found a bug? Fork this project to help make Chai even better. Even this documentation site is open source and available for contribution.

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