testing – Page 20 – Türker Yıldırım

Model::shouldBeStrict in development, and what it catches

NoteApril 13, 20222 min read

One call turns on three separate checks that each convert a silent misbehaviour into an exception. The third is the one with the largest immediate yield, because a…

Redis functions replace the Lua scripts nobody could version

Deep diveApril 12, 202210 min read

7.0 in April, and a script registry that survives a restart. EVAL with a SHA nobody can map back to source.

A test that asserts on a duration is a flaky test

NoteApril 6, 20221 min read

A CI runner is shared, throttled and occasionally slow, so any assertion about wall-clock time fails eventually for reasons unrelated to the code. Query counts and memory are…

The N+1 that was in the authorisation layer

Deep diveApril 4, 202210 min read

A policy check that loads the model’s owner, per row. 200 queries on a page with 50 items and correct eager loading.

Moved blocks, and the Terraform refactor that destroyed nothing

Deep diveMarch 30, 202210 min read

1.1, and a block that renames a resource without destroying it. Renaming a module meant a plan that wanted to drop a database.

A path repository, for the package you are writing today

NoteMarch 28, 20222 min read

A path repository symlinks a local directory into vendor, so a change to the package is visible immediately without a version, a tag or a push. The symlink…

StrictMode double-invokes effects in development, deliberately

NoteMarch 25, 20222 min read

18 mounts, unmounts and remounts every component once in development under StrictMode, so an effect without cleanup runs twice and shows it. Every failure it produces is a…

Concurrent rendering is not a feature you turn on

Deep diveMarch 15, 202214 min read

18 in March, after two years of alpha, and createRoot is the whole opt-in. Then a fortnight of consequences.

The test suite that took twelve minutes and now takes ninety seconds

Deep diveMarch 8, 202210 min read

Twelve minutes, six times a day, per developer. Nobody ran it locally, so it only ever failed in CI.

Effects running twice in StrictMode break a naive test

NoteMarch 8, 20222 min read

A test asserting that a fetch happened once fails under React 18 development mode, and the test is wrong rather than the framework. Loosening the assertion to toHaveBeenCalled…