Counter reducer

Author: alexandr-g

src/features/counter/counterReducer.ts

@@ -0,0 +1,17 @@
+import { INCREMENT_COUNTER, DECREMENT_COUNTER } from './actionTypes'
+import { CounterActionTypes } from './types'
+
+const initialState = {
+  value: 0,
+}
+
+export default (state = initialState, action: CounterActionTypes) => {
+  switch (action.type) {
+    case INCREMENT_COUNTER:
+      return { ...state, value: state.value + 1 }
+    case DECREMENT_COUNTER:
+      return { ...state, value: state.value - 1 }
+    default:
+      return state
+  }
+}