David Tengeri

This seems a nice ticket to work on during the hacktoberfest. I am happy to take this if it is available.

@rrousselGit What would be the preferred way of implementation of `. toHaveBeenCalled()` and its variants? Is it okay to rely on mocktail or mockito? Or a custom implementation is expected...

@rrousselGit I plan to start with the followings. Let me know your thoughts: _.toHaveLength(number)_ This will be a List specific matcher. ```dart expect([1,2]).toHaveLength(2); // PASS expect([1,2]).toHaveLength(1); // FAIL ``` _.toHaveProperty(dynamic...

@rrousselGit I am not sure about the usefulness of `toBeFalsy()` and `toBeTruthy()`, I am happy to remove them.

Any update on this?