Menene gwaje wa haɗa jiya?

Question

Accepted Answer

**Gwaje wa haɗa jiya** yana tabbatar da cewa **marubuta da waje da jiya suna aiki daidai a tare** — gwaje wa wulakanci da wurarin haɗa jiya (kamar lambar da gida data, aiwatarwa suna kira juna, ko moduli wajen tara). Yana kama jiya da matsayi da gwaje na raka (wanda ke kewar raka) ba sa karbar.

## Abin da gwaje wa haɗa jiya ya tabbatar

```text
Integration tests verify COMPONENTS WORKING TOGETHER (not in isolation):
  → code + DATABASE (does the data layer actually work with a real DB?)
  → service A calling service B / an external API
  → multiple modules/units combined; the integration POINTS between them
→ catches issues in how parts INTERACT — which unit tests (isolated) can't catch.
```

## Me kamar gwaje wa haɗa jiya (gwargwade da gwaje na raka)

```text
UNIT tests isolate units (mocking dependencies) → fast, but DON'T verify real integration:
  → a unit can pass its tests but FAIL when combined (wrong assumptions about a dependency,
    a real DB query that's wrong, an API contract mismatch, config issues)
INTEGRATION tests use REAL (or realistic) dependencies → catch these interaction bugs:
  → wiring/configuration errors, data layer issues, contract mismatches between components
→ Integration tests verify the parts actually work TOGETHER.
```

## Misali da la'akari

```js
// integration test: the repository actually works with a (test) database
test('UserRepository saves and retrieves a user', async () => {
  const repo = new UserRepository(testDb);     // REAL test database
  await repo.save({ name: 'Ann' });
  const user = await repo.findByName('Ann');    // real query
  expect(user.name).toBe('Ann');
});
```

```text
→ SLOWER than unit tests (real I/O, setup); use a TEST database/environment
→ Test important integration points (data access, key service interactions, APIs)
→ Fewer than unit tests (the pyramid middle); manage test data/state carefully
```

## Me ya sa haka ma

Antawa gwaje wa haɗa jiya yana da mahimmanci saboda yana **kama waje da matsayi wajen gwaje na raka ba za su iya** — matsaloli ta yadda marubuta suna aiki tare — saboda haka yana da dama don cikakken gwaje.

Yadda gwaje na raka ke tabbatar da raka da kila ɗaya kewar waje (miƙa hanyar gida), wannan kewarwa yana nufin su **ba za su iya tabbatar da gaske haɗa jiya**: raka iya cika duka gwajennsa amma rashin aiki lokacin da a tabbata haɗa shi da waje (saboda kuskure game da ire na gida, bugun gida data zai kasua, API ido ba ta daidaita, ko matsalolin daidaita). **Gwaje wa haɗa jiya** suna cika wannan bubuje ta hanyar gwaje wa **marubuta aiki tare da gaske (ko ainihi) gida** — tabbatar da cewa lambar tabbas aiki da gaske gida data, cewa aiwatarwa suna wulakanci daidai, da cewa wurarin haɗa aiki — kama matakin tsinke, data-layer, da matsayi matsaloli da kewarren gwaje na raka ba sa kama.
"] Tukarar wannan haɗa ido (gwaje na raka don raka da kila ɗaya, gwaje wa haɗa jiya don gaske wulakanci) ita ce maɗaukaki ga cikakken gwaje, tun ba ɗaya ba a gida.

Antawa **la'akari** — cewa gwaje wa haɗa jiya suna jiya kallon (gaske I/O da tara, saboda su zaune a tsakiya gida da kaɗan fiye da gwaje na raka), amfani test gida data/muhatarru, miƙa mahimmanci wurarin haɗa jiya (ire data, maɓuɓɓugun aiwatarwa wulakanci, APIs), da bukatar kulwal test data/yanayi tara — yana nuni da ainihi gwaje wa haɗa jiya.

Gwaje wa haɗa jiya suna ba da sani cewa sassare aɓuɓɓuka suna aiki, waɗanda gwaje na raka ba kaɗai ba za su iya ba.

Tun da gaske aikace-aikacen jiya waɗanda suke ya ɓuɓɓugun wulakanci marubuta da haɗa jiya matsaloli (gida data matsaloli, ido matsaloli, daidaita kuskure) suna gida da ba sa kama da gwaje na raka, da tun gwaje wa haɗa jiya yana kama su ta hanyar tabbatar marubuta suna aiki tare, antawa gwaje wa haɗa jiya yana da ƙarfi, ainihi-daidai ilimi — maɓuɓɓugun hade da gwaje na raka wanda yana kama haɗa matsaloli, mahimmanci ga cikakken gwaje wanda yana tabbatar ba raka ba kaɗai amma cewa sassar tsarin aiki tare daidai.