Aiki da raguwa nini, kuma me yasa dole aiki bai bugi ba?

Question

Accepted Answer

**Aiki** abu ne mai sauki wanda ke bayyana *abin da ya faru* ; **raguwawa** darajiya ne ta raguwa wanda ke karban jipin kasuwanci na yanzu da aiki da kuma gaidar jipin *gida* na gida. Juna suna aiwatar da mabu na jiyi.

## Aiki — bayyana abubuwan da suka faru

```js
// just data: a `type` (required) + any payload
{ type: "todos/added", payload: { id: 1, text: "Learn Redux" } }
{ type: "todos/toggled", payload: 1 }
```

Aiki ba sa *yi* koma — sunayin bayyana abubuwan da suka faru. Suna da suna a lokaci wanda ya gabata ("an saka", "an juyar da") yana nuna cewa suna rubuta abin da ya faru.

## Raguwawa — kididdige jipin gida na gida

```js
function todosReducer(state = [], action) {
  switch (action.type) {
    case "todos/added":
      return [...state, action.payload];              // new array
    case "todos/toggled":
      return state.map(t =>                             // new array, new object for the changed one
        t.id === action.payload ? { ...t, done: !t.done } : t
      );
    default:
      return state;                                     // unknown action → unchanged
  }
}
```

Alama na raguwawa shine `(state, action) => newState`. Dole ya mayar da **sabuwa** jipin kabuwa/jirgin (ba tare da canja ba), kalila canja abin da aka bada shi.

## Me yasa aiki dole a yi daidai

Takardarwa mai kyau: (1) yana bada jiya gatari guda da gida don abin da aka bada shi, da (2) ba shi da **alamomi na gida**. Raguwawa dole su bi kaida biyu guda:

```js
// ❌ NOT pure — breaks everything
function badReducer(state, action) {
  state.value++;              // ❌ mutates input (breaks change detection, time-travel)
  fetch("/api/log");          // ❌ side effect (non-deterministic, untestable)
  return { value: Math.random() }; // ❌ non-deterministic output
}
```

Kamancecewa yana ba da hanya na Redux:

```text
✓ Predictability   — same state + action ALWAYS gives the same result
✓ Time-travel / replay — you can re-run actions to reproduce any state
✓ Testability      — just call reducer(state, action) and assert; no mocks needed
✓ Change detection — returning new references lets the UI detect changes
```

Alamomi na gida (kare API, yada,miji) sun nuna **middleware** (thunks/sagas) ko ta'irawa — ba a raguwawa ba.

## Me yasa akai mahimmanci

Alaka/raguwawa model ne wadanda suke tuni ta Redux-style jiyin mamaki da dalilin da yasa ya saya kula da bincike.

Dabarin kamancecewa ba ita jadwali ba: ita ce *abin da ya xi* sasanta tafiya, tunawa ta aiki, da karamin bincike mai sahi, da dalilin da yasa alamomi na gida dole a kasua a waje.

Pattern ike-mun-ita-safi-gida da jaraba na jiya suke yin gaida a Redux, NgRx, useReducer, da gida — jin haka (da hanya na kiyaye raguwawa daidai) shine ainihin bincike na jiyi.