unexpected-immutable
Assertions

Map

to have keys
to have property

Collection

to be empty
to be non empty
to equal
to have length
to have size

to have length

<Collection> [not] to have length <number>

Alias for to have size. Asserts that the immutable collection has the expected size.

expect(new List([ 1, 2, 3]), 'to have length', 3);