The Importance of TDD

Source: Dev.to

The Problem

I built an “awesome” API with 12 parameters.
It was garbage.
Nobody could use it without a PhD in my brain.

After years of backend development, I learned Test Driven Development (TDD) the hard way. I was coding deep in the weeds, adding parameter after parameter because I needed the data. When I finally wrote tests, reality hit:

• Callers didn’t have half the info I required.
• My “beautiful” API was unusable.

I’d forgotten the most important person: the user.

What TDD Changes

TDD flips this backwards thinking. You write tests for code you wish existed, then build code to pass those tests.

1. Red – write a failing test.
2. Green – implement just enough code to make the test pass.
3. Refactor – improve the code while keeping the tests green.

Repeat.

Benefits

• Forces you to think like your caller, not your compiler.
• Saves massive debugging time later.
• Test cases become a safety net when libraries update or teammates make changes.

“If it’s worth building, it’s worth testing. If it’s not worth testing, why waste time…”