Making a Leaner Switch Case by Refactoring Code in REDUCERS

Ch-sriram · Sep 1, 2020 · e85c53e · e85c53e
1 parent 1a6d06b
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Showing 3 changed files with 68 additions and 59 deletions.
diff --git a/README.md b/README.md
@@ -131,3 +131,4 @@ Dependency Installation: **`npm i --save redux-thunk`**
 14. Handling Purchases & Updating the UI: [Commit Details](https://github.com/Ch-sriram/burger-builder/commit/c42f5f9d6b1cc7c7d948028e34bd21f64eecd8c6)
 15. Resetting the `totalPrice` after Purchases: [Commit Details](https://github.com/Ch-sriram/burger-builder/commit/ddc8161cff3e022fa088e0f5cc42b2b06ea6caa4)
 16. Fetching Orders via Redux & Refactoring the **`REDUCERS`** using Custom Utility Function(s): [Commit Details](https://github.com/Ch-sriram/burger-builder/commit/e39ea9c1d7c92ca92cc3639ac6be175c904e87c8)
+17. Making a Leaner Switch Case by Refactoring Code in **`REDUCERS`**: [Commit Details]()
diff --git a/src/store/reducers/burgerBuilder.js b/src/store/reducers/burgerBuilder.js
@@ -14,45 +14,51 @@ const INGREDIENT_PRICES = {
   bacon: 0.7,
 };
 
+const ADD = true, SUBTRACT = false;
+
+const modifyIngredient = (state, action, modifier) => {
+  const updatedIngredient = {
+    [action.ingredientName]:
+      modifier === ADD
+        ? state.ingredients[action.ingredientName] + 1
+        : state.ingredients[action.ingredientName] - 1,
+  };
+  const updatedIngredients = updateObject(state.ingredients, updatedIngredient);
+  const updatedState = {
+    ingredients: updatedIngredients,
+    totalPrice:
+      modifier === ADD
+        ? state.totalPrice + INGREDIENT_PRICES[action.ingredientName]
+        : state.totalPrice - INGREDIENT_PRICES[action.ingredientName],
+  };
+  return updateObject(state, updatedState);
+};
+
+const setIngredients = (state, action) => {
+  let price = initialState.totalPrice;
+  for (let ingredient of Object.entries(action.ingredients)) 
+    price += INGREDIENT_PRICES[ingredient[0]] * ingredient[1];
+
+  return updateObject(state, {
+    ingredients: {
+      salad: action.ingredients.salad,
+      bacon: action.ingredients.bacon,
+      cheese: action.ingredients.cheese,
+      meat: action.ingredients.meat,
+    },
+    totalPrice: price,
+    error: false,
+  });
+}
+
+const fetchIngredientsFailed = (state, action) => updateObject(state, { error: true, });
+
 const reducer = (state = initialState, action) => {
   switch (action.type) {
-    case actionTypes.ADD_INGREDIENT:
-      const updatedIngredient = { [action.ingredientName]: state.ingredients[action.ingredientName] + 1 };
-      const updatedIngredients = updateObject(state.ingredients, updatedIngredient);
-      const updatedState = {
-        ingredients: updatedIngredients,
-        totalPrice: state.totalPrice + INGREDIENT_PRICES[action.ingredientName],
-      };
-      return updateObject(state, updatedState);
-
-    case actionTypes.REMOVE_INGREDIENT:
-      const updatedIng = { [action.ingredientName]: state.ingredients[action.ingredientName] - 1 };
-      const updatedIngs = updateObject(state.ingredients, updatedIng);
-      const updated_State = {
-        ingredients: updatedIngs,
-        totalPrice: state.totalPrice - INGREDIENT_PRICES[action.ingredientName],
-      };
-      return updateObject(state, updated_State);
-
-    case actionTypes.SET_INGREDIENTS:
-      let price = initialState.totalPrice;
-      for (let ingredient of Object.entries(action.ingredients)) {
-        price += INGREDIENT_PRICES[ingredient[0]] * ingredient[1];
-      }
-      return updateObject(state, {
-        ingredients: {
-          salad: action.ingredients.salad,
-          bacon: action.ingredients.bacon,
-          cheese: action.ingredients.cheese,
-          meat: action.ingredients.meat,
-        },
-        totalPrice: price,
-        error: false,
-      });
-
-    case actionTypes.FETCH_INGREDIENTS_FAILED:
-      return updatedState(state, { error: true, });
-
+    case actionTypes.ADD_INGREDIENT: return modifyIngredient(state, action, ADD);
+    case actionTypes.REMOVE_INGREDIENT: return modifyIngredient(state, action, SUBTRACT);
+    case actionTypes.SET_INGREDIENTS: return setIngredients(state, action);
+    case actionTypes.FETCH_INGREDIENTS_FAILED: return fetchIngredientsFailed(state, action);
     default: return state;
   }
 };

diff --git a/src/store/reducers/order.js b/src/store/reducers/order.js
@@ -7,30 +7,32 @@ const initialState = {
   purchased: false,
 };
 
+const purchaseInit = (state, action) => updateObject(state, { purchased: false, });
+const purchaseBurgerStart = (state, action) => updateObject(state, { loading: true, });
+
+const purchaseBurgerSuccess = (state, action) => {
+  const newOrder = updateObject(action.orderData, { id: action.orderID, });
+  return updateObject(state, {
+    loading: false,
+    purchased: true,
+    orders: state.orders.concat(newOrder),
+  });
+};
+
+const purchaseBurgerFail = (state, action) => updateObject(state, { loading: false, });
+const fetchOrdersStart = (state, action) => updateObject(state, { loading: true, });
+const fetchOrdersSuccess = (state, action) => updateObject(state, { orders: action.orders, loading: false, });
+const fetchOrdersFail = (state, action) => updateObject(state, { loading: false, });
+
 const reducer = (state = initialState, action) => {
   switch (action.type) {
-    case actionTypes.PURCHASE_INIT:
-      return updateObject(state, { purchased: false, });
-    case actionTypes.PURCHASE_BURGER_START:
-      return updateObject(state, { loading: true, });
-    case actionTypes.PURCHASE_BURGER_SUCCESS:
-      const newOrder = updateObject(action.orderData, { id: action.orderID, });
-      return updateObject(state, {
-        loading: false,
-        purchased: true,
-        orders: state.orders.concat(newOrder),
-      });
-    case actionTypes.PURCHASE_BURGER_FAIL:
-      return updateObject(state, { loading: false, });
-    case actionTypes.FETCH_ORDERS_START:
-      return updateObject(state, { loading: true, });
-    case actionTypes.FETCH_ORDERS_SUCCESS:
-      return updateObject(state, {
-        orders: action.orders,
-        loading: false,
-      });
-    case actionTypes.FETCH_ORDERS_FAIL:
-      return updateObject(state, { loading: false, });
+    case actionTypes.PURCHASE_INIT: return purchaseInit(state, action);
+    case actionTypes.PURCHASE_BURGER_START: return purchaseBurgerStart(state, action);
+    case actionTypes.PURCHASE_BURGER_SUCCESS: return purchaseBurgerSuccess(state, action);
+    case actionTypes.PURCHASE_BURGER_FAIL: return purchaseBurgerFail(state, action);
+    case actionTypes.FETCH_ORDERS_START: return fetchOrdersStart(state, action);
+    case actionTypes.FETCH_ORDERS_SUCCESS: return fetchOrdersSuccess(state, action);
+    case actionTypes.FETCH_ORDERS_FAIL: return fetchOrdersFail(state, action);
     default: return state;
   }
 };