EmptyCollectionConstraint - jnm2/nunit-docs-wiki GitHub Wiki

The EmptyCollectionConstraint tests if a Collection or other IEnumerable is empty. An ArgumentException is thrown if the actual value is not an IEnumerable or is null.

EmptyCollectionConstraint()

Is.Empty

Assert.That(new int[] { }, Is.Empty);
Assert.That(new int[] { 1, 2, 3 }, Is.Not.Empty);

Note: Is.Empty actually creates an EmptyConstraint. Subsequently applying it to an IEnumerable or ICollection causes an EmptyCollectionConstraint to be created.