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Testing Best Practices or The 5 Habits of Highly Effective Tests Noel Rappin @noelrap Wednesday, April 25, 12

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What is an "effective" test? Wednesday, April 25, 12

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"I get paid for code that works, not for tests" -- Kent Beck Wednesday, April 25, 12

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Effective tests help you sustainably deliver features Wednesday, April 25, 12

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How do you know tests are effective? Wednesday, April 25, 12

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Shallow bugs Wednesday, April 25, 12

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Not staring into space watching dots fly across the screen Wednesday, April 25, 12

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Relatively little time spent fixing test problems Wednesday, April 25, 12

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Simple, clean design Wednesday, April 25, 12

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One thing I didn't say... Wednesday, April 25, 12

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Coverage Wednesday, April 25, 12

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BDD is a software design process Wednesday, April 25, 12

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How do you know your tests aren't effective? Wednesday, April 25, 12

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Lots of test fragility Wednesday, April 25, 12

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Test-based slowdowns Wednesday, April 25, 12

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No confidence in your ability to change Wednesday, April 25, 12

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Why is testing effective? Wednesday, April 25, 12

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Expressing requirements in code Wednesday, April 25, 12

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Universal client Wednesday, April 25, 12

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Rapid feedback Wednesday, April 25, 12

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Canary Wednesday, April 25, 12

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"More Testable" is a legitimate engineering goal Wednesday, April 25, 12

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Test-Driven vs. Test First Wednesday, April 25, 12

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What makes for an effective test? Wednesday, April 25, 12

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Tests are code without tests! Wednesday, April 25, 12

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Tests have two lives Wednesday, April 25, 12

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1. While you are creating the feature Wednesday, April 25, 12

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2. Until the heat death of the universe Wednesday, April 25, 12

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All tests have costs Some tests have value Wednesday, April 25, 12

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Simple Well-defined Independent Fast Truthful Wednesday, April 25, 12

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Simple Wednesday, April 25, 12

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A test is simple if its purpose is immediately clear simple Wednesday, April 25, 12

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Fixtures Long tests Bad naming Clever simple Wednesday, April 25, 12

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Good naming Factories Refactoring tests simple Wednesday, April 25, 12

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If the tests can't be simple, the code is bad simple Wednesday, April 25, 12

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Tests not written via TDD often have trouble being simple simple Wednesday, April 25, 12

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Well-defined Wednesday, April 25, 12

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A test is well-defined if it gives the same result every time well-defined Wednesday, April 25, 12

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Dates Random well-defined Wednesday, April 25, 12

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Encapsulation Mocks well-defined Wednesday, April 25, 12

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Independent Wednesday, April 25, 12

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A test is independent if it does not depend on external state independent Wednesday, April 25, 12

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Global data Fixtures independent Wednesday, April 25, 12

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Factories Teardown/ Transactions independent Wednesday, April 25, 12

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Fast Wednesday, April 25, 12

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A test is fast if it is fast fast Wednesday, April 25, 12

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Too many objects Databases Third Party Frameworks fast Wednesday, April 25, 12

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Encapsulation Unit testing fast Wednesday, April 25, 12

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If your tests are not fast, you can not be test-driven fast Wednesday, April 25, 12

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Truthful Wednesday, April 25, 12

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A test is truthful if it accurately reflects the underlying code truthful Wednesday, April 25, 12

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Too specific Mocks Surface values truthful Wednesday, April 25, 12

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Indirect testing Defensive mocking Understanding requirements truthful Wednesday, April 25, 12

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Test both sides of a problem Wednesday, April 25, 12

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The testing pyramid and chains of responsibility Wednesday, April 25, 12

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Noel Rappin @noelrap railsrx.com Wednesday, April 25, 12