Added gitignore

vidow-front/src/features/counter/counterSlice.ts

@@ -0,0 +1,82 @@
+import { createAsyncThunk, createSlice, PayloadAction } from '@reduxjs/toolkit'
+
+import type { AppState, AppThunk } from '../../app/store'
+import { fetchCount } from './counterAPI'
+
+export interface CounterState {
+  value: number
+  status: 'idle' | 'loading' | 'failed'
+}
+
+const initialState: CounterState = {
+  value: 0,
+  status: 'idle',
+}
+
+// The function below is called a thunk and allows us to perform async logic. It
+// can be dispatched like a regular action: `dispatch(incrementAsync(10))`. This
+// will call the thunk with the `dispatch` function as the first argument. Async
+// code can then be executed and other actions can be dispatched. Thunks are
+// typically used to make async requests.
+export const incrementAsync = createAsyncThunk(
+  'counter/fetchCount',
+  async (amount: number) => {
+    const response = await fetchCount(amount)
+    // The value we return becomes the `fulfilled` action payload
+    return response.data
+  }
+)
+
+export const counterSlice = createSlice({
+  name: 'counter',
+  initialState,
+  // The `reducers` field lets us define reducers and generate associated actions
+  reducers: {
+    increment: (state) => {
+      // Redux Toolkit allows us to write "mutating" logic in reducers. It
+      // doesn't actually mutate the state because it uses the Immer library,
+      // which detects changes to a "draft state" and produces a brand new
+      // immutable state based off those changes
+      state.value += 1
+    },
+    decrement: (state) => {
+      state.value -= 1
+    },
+    // Use the PayloadAction type to declare the contents of `action.payload`
+    incrementByAmount: (state, action: PayloadAction<number>) => {
+      state.value += action.payload
+    },
+  },
+  // The `extraReducers` field lets the slice handle actions defined elsewhere,
+  // including actions generated by createAsyncThunk or in other slices.
+  extraReducers: (builder) => {
+    builder
+      .addCase(incrementAsync.pending, (state) => {
+        state.status = 'loading'
+      })
+      .addCase(incrementAsync.fulfilled, (state, action) => {
+        state.status = 'idle'
+        state.value += action.payload
+      })
+  },
+})
+
+export const { increment, decrement, incrementByAmount } = counterSlice.actions
+
+// The function below is called a selector and allows us to select a value from
+// the state. Selectors can also be defined inline where they're used instead of
+// in the slice file. For example: `useSelector((state: RootState) => state.counter.value)`
+export const selectCount = (state: AppState) => state.counter.value
+
+// We can also write thunks by hand, which may contain both sync and async logic.
+// Here's an example of conditionally dispatching actions based on current state.
+export const incrementIfOdd =
+  (amount: number): AppThunk =>
+  (dispatch, getState) => {
+    const currentValue = selectCount(getState())
+    if (currentValue % 2 === 1) {
+      dispatch(incrementByAmount(amount))
+    }
+  }
+
+export default counterSlice.reducer