Index

Day 8 - Unit tests

• The tests and the production code are written together
• If we work this way, those tests will cover virtually all of our production code

The three laws of TDD (test driven development)

• You may not write production code until you have written a failing unit test
• You may not write more of a unit test than is sufficient to fail, and not compiling is failing
• You may not write more production code than is sufficient to pass the currently failing test

Keeping the tests clean

• Having dirty tests is equivalent to having no tests

A dual standard

• Test code must be simple, succinct and expressive, but it doesn’t need to be as efficient as production code. After all, it runs in a test environment

Single concept per test

F.I.R.S.T. (rules for clean tests)

• Fast: tests should be fast
• Independent: test should not depend on each other
• Repeatable: test should be repeatable in every environment
• Self-validating: tests should have a boolean output
• Timely: tests should be written just before the production code that makes them pass