In order to have a better failure message, toBeNull()
should be used upon
asserting expections on null value.
This rule triggers a warning if toBe()
is used to assert a null value.
expect(null).toBe(null);
This rule is enabled by default.
The following pattern is considered warning:
expect(null).toBe(null);
The following pattern is not warning:
expect(null).toBeNull();