to contain

Asserts an array (or array-like object) contains one or more items.

expect([0, 1, 2], 'to contain', 1);

expect([ { name: 'John Doe' }, { name: 'Jane Doe' } ], 'to contain', { name: 'Jane Doe' });

expect([0, 1, 2], 'to contain', 0, 2);

In case of a failing expectation you get the following output:

expect([ { name: 'John Doe' }, { name: 'Jane Doe' } ], 'to contain', { name: 'Jonnie Doe' });

expected [ { name: 'John Doe' }, { name: 'Jane Doe' } ]

to contain { name: 'Jonnie Doe' }

This assertion can be negated using the not flag:

expect([ { name: 'John Doe' }, { name: 'Jane Doe' } ], 'not to contain', { name: 'Jonnie Doe' });

In case of a failing expectation you get the following output:

expect([ { name: 'John Doe' }, { name: 'Jane Doe' } ], 'not to contain', { name: 'Jane Doe' });

expected [ { name: 'John Doe' }, { name: 'Jane Doe' } ]

not to contain { name: 'Jane Doe' }

[

{ name: 'John Doe' },

{ name: 'Jane Doe' } // should be removed

]