LiveTest automation · CI/CD

Flaky test suite

Run a CI suite 20 times. Fix sleeps and shared data, add workers and retries — and see when a retry hides a real bug.

Build 20 of 20 · 20.0 s✓ Passed

Wait for the condition (no sleep)Each test owns its data

Parallel workers4

Retries per failed test2

Green builds17 / 20

Average build19.2 s

Retries used52

Real bug hidden5 / 5

Retries hid a real bug. The race condition failed in 5 of 20 builds, and a retry turned it green 5 times. Allow one retry at most, and count every one.

passedfailedretrythe real bugbuild where a retry hid it

How it works

1Twelve tests sleep for 3 seconds, eight share data, and one finds a real bug in a quarter of runs. The rest just pass.
2Waiting for the condition makes the suite faster and removes the timing failures. Giving each test its own data removes the failures that only appear in parallel.
3Retries turn builds green — including the one run where the bug showed up. Retry at most once, and count every retry.

Read the post: How to fix a slow, flaky test suite

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