added validation when adding a book

front/src/api.js

@@ -3,13 +3,13 @@ import { ref } from 'vue'
 const baseUrl = "http://localhost:8080"
 
 function useFetch(url) {
-  const data = ref(null)
-  const error = ref(null)
+  const data = ref(null);
+  const error = ref(null);
 
   fetch(url)
     .then((res) => res.json())
     .then((json) => (data.value = json))
-    .catch((err) => (error.value = err))
+    .catch((err) => (error.value = err));
 
   return { data, error }
 }
@@ -19,11 +19,11 @@ export function getBooks() {
 }
 
 export function postBook(book) {
-  fetch(baseUrl + '/book', {
+  return fetch(baseUrl + '/book', {
     method: 'POST',
     headers: {
       'Content-Type': 'application/json'
     },
     body: JSON.stringify(book.value)
-  });
+  })
 }