Optivem Journal

Optivem Journal

Test Driven Development

TDD is NOT about high code coverage

Code Coverage shows you what code you haven't executed, not how good your tests are

Valentina Jemuović's avatar
Valentina Jemuović
Oct 17, 2025
∙ Paid
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🔒 Hello, this is Valentina with a premium issue of the Optivem Journal. I help Engineering Leaders & Senior Software Developers apply TDD in Legacy Code.


You can achieve 100% code coverage having tests with zero assertions!

TDD isn’t about having useless or illogical tests just for the sake of reaching a certain metric.

The main goal of TDD is that we’re driven by specifications, and that the code we produce is testable and aligned with specifications.

High code coverage is just a byproduct of TDD, but not the goal.

100% code coverage, 0 assertions

You can literally hit every line of code with your tests — and still have no validation of behavior. This is called a “zero assertion test“.

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© 2025 Valentina Jemuović, Optivem
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