Elixir TDD Enforcement: The Iron Law

THE IRON LAW

NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST

Not sometimes. Not usually. ALWAYS.

If you write production code before a failing test, DELETE IT and start over.

WHEN THIS SKILL APPLIES

• Implementing ANY new function
• Fixing ANY bug
• Adding ANY feature
• Modifying ANY behavior
• Refactoring ANY code

If you're changing .ex files in lib/, this skill is MANDATORY.