Apa iku flaky tests lan carane ngatasi?

Question

Accepted Answer

**Flaky tests** yaiku test sing **lulus utawa gagal ora konsisten** tanpa ana owah-owahan kode — kadhang kala lulus, kadhang kala gagal ing kode sing padha. Iki dadi masalah serius amarga ngilangi kapercayan marang test suite. Ngerti sebab lan cara ngatasi iku penting.

## Apa iku flaky tests lan kenapa iku ndadake cilaka

```text
A FLAKY test gives INCONSISTENT results (pass sometimes, fail other times) on the SAME code:
  → harmful: ERODES TRUST — people start ignoring failures ("oh, it's just flaky") →
    real failures get missed too
  → waste time on false alarms / re-runs; break CI; reduce confidence in the whole suite
→ Flaky tests are worse than no test if they make people distrust all tests.
```

## Sebab-sebab umum

```text
✗ TIMING / async → race conditions; not waiting properly for async operations (a top cause
  in UI/E2E tests); arbitrary sleeps
✗ ORDER DEPENDENCE → tests depending on each other / shared mutable state
✗ EXTERNAL dependencies → real network/services (network blips, rate limits, downtime)
✗ NON-DETERMINISM → time/dates, randomness, timezone, locale
✗ Test ENVIRONMENT → leftover state, uncleaned data, concurrency/parallelism issues
```

## Ngatasi lan nglola flaky tests

```text
✓ Fix the ROOT CAUSE: wait for conditions (not sleeps); make tests INDEPENDENT and clean
  up state; MOCK external dependencies; control time/randomness (inject them)
✓ Ensure proper isolation (no shared state, no order dependence)
✓ Don't just RETRY blindly (it hides the problem) — investigate and fix
✓ QUARANTINE persistently flaky tests (isolate so they don't block) WHILE fixing them
✓ Treat flakiness seriously — track and address it (it degrades the whole suite)
```

## Dene iku penting

Ngerti flaky tests lan carane ngatasi iku penting amarga **flaky tests iku masalah serius lan umum sing ngrusak nilai sak sakabéhé test suite**, dadi iku ilmu praktek sing bernilai.

Flaky test (lulus utawa gagal ora konsisten ing kode sing padha) utamané ndadake cilaka amarga **ngilangi kapercayan**: yèn test gagal ora bisa dikarepake, wong-wong mulai nglirwakake kegagalan ("iku mung flaky"), iki tegese **kegagalan nyata bisa kelewatan** — dadi flakiness ngrusak kepercayaan marang kabéhé suite, bisa dadi luwih parah tinimbang ora ana owah-owahan.

Ngerti cilaka iki medorong ambil flakiness kanthi serius.

Ngerti **sebab-sebab umum** — **timing/async issues** (race conditions, ora pabuatan menunggu async operations kanthi bener, sleep random — panyebab utama utamané ing UI/E2E tests), **order dependence** (tests sing gumantung siji sama liyane utawa shared state), **external dependencies** (real network/services sing ana blips lan downtime), **non-determinism** (wektu, randomness, timezone, locale), lan **environment issues** (leftover state, concurrency) — perlu kanggo diagnosa flakiness.

Ngerti carane **ngatasi lan nglola** — ngatasi root causes (menunggu conditions tinimbang sleeps, gawe tests independent lan bersih, nggawe mock external dependencies, ngontrol wektu lan randomness), njamin isolation, **ora buta-butaan retry** (sing ndhelikake masalah), nggawe quarantine persistently flaky tests sambil ngatasi, lan nlakoni flakiness minangka masalah serius sing perlu dilacak lan ditarusi — nunjukake pendekatan sing bener.

Kamangka flaky tests iku masalah umum lan serius sing ngrusak kapercayan lan nilai test suite (masalah nyata ing akeh real-world projects), lan amarga ngerti sebab-sebab lan penanganan bener-benere (ngatasi root causes, isolation, ora mung retry) perlu kanggo njaga test suite sing bisa dipercaya, ngerti flaky tests iku ilmu praktek sing bernilai lan penting — ngatasi masalah real-world testing sing signifikan, penting kanggo njaga test suite tetep reliable lan dipercaya, lan nunjukake maturity praktek kanggo ngatasi salah sawijining masalah testing sing paling mumet lan ngrusak.