https://www.blog-des-telecoms.com/en/tags/test-smells/Recent content in Test-Smells on Mathias WOLFFHugoen-US<a href="https://www.blog-des-telecoms.com">Blog des télécoms</a> © 2009 - 2026 by <a href="https://www.linkedin.com/in/mathias-wolff-47a7941/">Mathias WOLFF</a> is licensed under <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA 4.0</a><img src="https://mirrors.creativecommons.org/presskit/icons/cc.svg" style="max-width: 1em;max-height:1em;margin-left: .2em;"><img src="https://mirrors.creativecommons.org/presskit/icons/by.svg" style="max-width: 1em;max-height:1em;margin-left: .2em;"><img src="https://mirrors.creativecommons.org/presskit/icons/nc.svg" style="max-width: 1em;max-height:1em;margin-left: .2em;"><img src="https://mirrors.creativecommons.org/presskit/icons/sa.svg" style="max-width: 1em;max-height:1em;margin-left: .2em;">Fri, 03 Jul 2026 19:06:13 +0200https://www.blog-des-telecoms.com/en/blog/measuring-test-quality-four-axes/Thu, 02 Jul 2026 09:00:00 +0200https://www.blog-des-telecoms.com/en/blog/measuring-test-quality-four-axes/<p><em>Article 4 of the series &ldquo;From Specification to Execution.&rdquo; The <a href="https://www.blog-des-telecoms.com/en/blog/who-writes-what-humans-ai-deterministic-tools" >previous article</a> discussed the distribution of roles between human, AI, and deterministic tools. We can now write tests. The more useful question remains: How do we know if they are worth anything?</em></p> <p>A case often cited by the authors of <a href="https://hypothesis.readthedocs.io/" class="link--external" target="_blank" rel="noreferrer" >Hypothesis</a> summarizes the problem well. A production JSON parser showed 95% coverage on an example-based test suite. The score looked good. Yet, as soon as it was fed into Hypothesis with arbitrary Unicode inputs, it broke in less than 30 seconds on a <em>surrogate</em> character. The tests existed. They didn&rsquo;t protect what they claimed to protect.</p>