Türker Yıldırım

testing

  • One flaky test split into three

    Note2 min read

    A test asserting three things across two systems, failing intermittently for three years, split into three tests that each assert one. Splitting is diagnosis rather than a fix…

  • The command bus we removed

    Deep dive10 min read

    A command bus introduced in 2021, and 88 commands with one handler each. A stack trace with four frames of dispatch before the work.

  • The test that had been quarantined since 2023

    Deep dive10 min read

    A quarantine list with a deadline, three extensions, and one test covering a payment path that had been skipped for three years.

  • Coverage on changed lines only

    Note1 min read

    A merge gate on the coverage of lines the pull request touched, which is a different and better question. A global coverage threshold is satisfiable by testing the…

  • A contract fixture that a consumer stopped publishing

    Note2 min read

    Four consumer-authored fixtures fetched nightly, and one that stopped updating in November. A fetch that falls back to a cached copy on failure is being helpful and is…

  • Reusable skills and agent definitions, and what they are actually for

    Deep dive18 min read

    turkerdev/ai-skills and turkerdev/ai-agents, and eighteen months of retyping the same instructions. Context is per-session and knowledge is not.

  • Deleting a module

    Deep dive10 min read

    A module built in 2022 for a product line discontinued in 2024. Eight thousand lines, a database schema and two scheduled jobs, all still running.

  • A pipeline described in one file, after four years of five

    Deep dive10 min read

    Five workflow files, two composite actions, and nobody able to say what runs when. A change that needed editing three files, one of them wrong.

  • Mutation testing on a third directory, and a worse score

    Note2 min read

    A technique applied to a third directory, with a score of thirty-eight per cent and a good reason. A low score on code whose correctness is asserted at…

  • A component gallery that renders every state

    Note1 min read

    A page rendering every component in every state, which is what finally let somebody else change the stylesheet. The states are the point rather than the components —…