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Testing value objects

Avatar for Fran Iglesias Fran Iglesias
November 02, 2018
Programming
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Testing value objects

How to test things like immutability
Avatar for Fran Iglesias

Fran Iglesias

November 02, 2018
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Transcript

  1. TDD 101 2. TDDing Value Objects

  2. TDDing Value Objects

  3. Value Object (DDD) Small object Represents a concept Equality based

    on value Immutable: • Should be created consistent • Mutators should return new instances

  4. So… How do you TDD a VO?

  5. TDD VO Think of an invalid example Write a test

    that fails expecting exception Make the test pass Repeat as needed to test invalid cases

  6. TDD VO Think of a valid example Write a test

    that fails asserting value Make the test pass

  7. TDD VO Equality Write a test that fails expecting inequality

    Make the test pass Then write a test that fails expecting equality Make the test pass

  8. TDD VO Immutability Think of a valid example of a

    mutator Write a test that fails expecting a different instance Make the test pass
  9. None