Test Before > Test After

By now, I hope we can all agree that unit tests are a good idea. I recently gave a presentation on why I think testing before writing production code (TDD) is better than testing after.

Code Quality

Only writing code to fix failing tests yields:

• Better tests
• Testable code
  • Decoupled
  • Fast
• Less rework
• High test coverage
  • Less debugger
• Simple
  • Less gold-plating

Continuous Integration

Minimizing time in Red and committing on Green yields:

• Compiling, tested code every ~10 minutes
• Ability to revert to last Green quickly

Improved Interfaces

Intelligent test names and coding from client's perspective yields

• Self-documenting code with clean, natural interfaces

// 👎
GetLog().Debug().Message("My message.");
Log(Priority.Debug, "My message.");

// 👍
void Debug_LogsDebugMessage() {
   Log.Debug("My message.");
   // Some assert
}

Testing after is work, TDD is fun!