Menene "single source of truth" yana nufin?

Question

Accepted Answer

**Single source of truth** yana nufin cewa kowane ɓangare na bayanai ana ajiya shi a **ɗaya zama** kawai, kuma komai da ke buƙatar shi yana karantawa daga can — maimakon adana kwafi maraya da za su iya shakowa.

## Matsalar da ya kare: ɗan sanyi da daban-dabanin jiha

```jsx
// ❌ the same data stored in two places → they can disagree
function Profile() {
  const [user, setUser] = useState({ name: "Ann" });
  const [displayName, setDisplayName] = useState("Ann"); // a COPY of user.name

function rename(newName) {
    setUser({ ...user, name: newName }); // updated user...
    // ...but forgot to update displayName → now they're out of sync! 🐛
  }
}
```

Lokacin da gida ɗaya ya kasance a jihi biyu, duk sahur ya dace tumanin canza dukansu — kuma tabbas an bar ɗaya, yana samar da kuyanga inda UI yana nuna kiyaye rashin jituwa.

## Gyara: tushe gida ɗaya, samun sauran

```jsx
// ✅ user.name is the single source; displayName is DERIVED, not stored
function Profile() {
  const [user, setUser] = useState({ name: "Ann" });
  const displayName = user.name.toUpperCase(); // computed on render — always in sync

function rename(newName) {
    setUser({ ...user, name: newName }); // one update, everything stays consistent
  }
}
```

Ajiya darajar canonical sau ɗaya; lissafi duk wanda da zarar sauran dashi. Babu komai da ya dace a kiyaye haɗi.

## Waje gida don amfani da wannan ƙa'ida

```text
✓ Don't copy props into state (the prop is the source)
✓ Don't store derived values (compute them: totals, filtered lists, formatted text)
✓ Global stores (Redux/Pinia): one store is the source for shared data
✓ Server data: cache it once (React Query) rather than copying into many components
✓ URL as source: filters/page in the URL, read from there
```

## Me yasa ya zama mahimmaci

Single source of truth shine tushen ƙa'ida mai yawa na jituwa tsararraki mai aminci — ya keɓe kalas gida kaɗai na kuyanga ƙaura da bayanain jami'a da ke shakowa.

Shima *me yasa* kuna samun daraja maimakon ajiyer su, *me yasa* kuna nisantar damje props cikin jiha, kuma *me yasa* jama'a gida na duniya suke cakarce bayanain da aka ba da jiya.

Lokacin da bayanai suke da gida ɗaya mai ƙawainiya kuma komai da sauran karantawa daga can, UI na ke zama cikakke ta gida.