TDD: Three easy mistakes

Back in 2014 I wrote a blog post listing three mistakes often made by folks who are new to test-driven development (TDD). It was a very long post, so I’ve taken the three parts and expanded each into its own article, also incorporating the comments I received in 2014. This is part 1.

Each time I visit a team that is relatively new to TDD I find the same basic mistakes cropping up every time. The three mistakes I see most often are:

Starting with error cases or null cases.

Writing tests for invented...