Design:

J.B. Rainsberger – Integrated Tests Are A Scam

• They don’t put pressure to the design
• You can’t possibly test all cases
• Introduce “Collaboration” tests
• Introduce “Contract” tests

Chris Parsons – Your Tests Are Lying To You

• Some tests are saying they’re Unit, but they’re actually Integration
• Good design is easy to test – Corey Haines
• Mockist vs Classist
• Mocks are isolated, fast & tell you about design flaws

Sandi Metz – The Design of Tests

• Messages to self – rarely tested
• Incoming messages – assert on result
• Outgoing messages – test for calling
• Outgoing queries – don’t test!
• Outgoing commands – expectations on mocks

Mocks:

Martin Fowler – Mocks Aren’t Stubs

• Mockist & behavior design VS Classist & STATE

Corey Haines – Yay! Mocks!

• Mocks lead to better design that easy to change
• OO design is about interactions & roles
• Delegate the “How”
• Don’t let mocks depend on other mocks

Gregory Moeck – Why You Don’t Get Mock Objects

• Mocks assert on messages
• Stub returns value
• Mock Roles, not concrete objects.

Gary Bernhardt – Test Isolation Is About Avoiding Mocks

• Nested stubs are telling something about the design
• Good TDDers don’t write nested mocks
• We write huge functions because there’s no pressure of testing them isolated.
• Isolated tests are microscope of object interactions
• Don’t let your tests make code less readable
• Don’t isolate “Collaborator” classes

Piotr Solnica – Mocking and Ruby

• Mock only what you own If you don’t own it, you don’t have control on it’s evolution
• Don’t mock just for speed
• Be aware that mocks introduce maintenance costs
• Keep mocks simple
• Mock rarely

Is TDD Dead?

series: Part 1 – 5