agama-project / agama / 28265195004

83%

Build Type

push

github

Committed by web-flow

Commit Message

fix(web): make DownloadFeedback timer tests deterministic (#3673)

## Problem

`DownloadFeedback.test.tsx` was intermittently failing in CI. The test
would pass for many runs, then fail without any related code changes,
making the failures difficult to reproduce and investigate.

## Root cause

The test relied on **real timers** for the success alert's auto-dismiss
behavior. Under CI load, this introduced a race condition:

* `waitFor` polls for the alert approximately every 50 ms.
* The alert is automatically dismissed after 10 ms via `setTimeout`.
* On a busy CI runner, the alert can appear and disappear between
polling intervals, causing the test to fail with **"Unable to find
alert"**.

On a typical development machine, the polling intervals are usually
short enough that the race rarely occurs. Under heavier CI load,
scheduling delays widen the gaps between polls, making the race
intermittent and difficult to reproduce locally.

Running the original test in a loop while saturating the CPU reproduced
the issue within a few iterations. The updated test remained stable
under the same conditions.

## Fix

The test now uses **fake timers**, making the alert dismissal
deterministic. The timeout only fires when the test explicitly advances
the clock, eliminating the race condition. Timing becomes a controlled
input rather than a source of nondeterministic behavior.

---

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

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4887 of 6804 branches covered (71.83%)

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8 existing lines in 1 file now uncovered.

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