Asserts that an Error instance has a given message:
expect(new Error('foobar'), 'to have message', 'foobar');
In case of a failing expectation you get the following output:
expect(new Error('foobar'), 'to have message', 'barfoo');
expected Error('foobar') to have message 'barfoo'
expected 'foobar' to equal 'barfoo'
-
foobar
+
barfoo