.toContain()

This assertion checks an array or string subject contains a value.

values are compared using strict equality

array

jestUnexpected(['a', 'b', 'c', 'd']).toContain('a');

jestUnexpected(['a', 'b', 'c', 'd']).toContain('e');

expected [ 'a', 'b', 'c', 'd' ]

to contain ContainSpec({ spec: 'e', value: undefined, nested: false })

If you need structural equality use .toContainEqual():

const something = {};

jestUnexpected(['a', something, 'c', 'd']).toContain(something);

const object = { foo: 'bar' };

const other = { foo: 'bar' };

jestUnexpected(['a', object, 'c', 'd']).toContain(other);

expected [ 'a', { foo: 'bar' }, 'c', 'd' ]

to contain ContainSpec({ spec: { foo: 'bar' }, value: undefined, nested: false })

jestUnexpected("foo bar").toContain("baz");

expected 'foo bar'

to contain ContainSpec({ spec: 'baz', value: undefined, nested: false })

foo bar