Ensure v1/products/ is never called without an identifier

We have identified a recurring issue in the code where attempts are made to access the first element of an empty array (`array[0]`), which results in `undefined`.

This issue occurs across all articles where the identifier is an empty array.

Additionally, our TypeScript implementation requires the `useGetV1ProductsIdentifier` hook to receive a string. To satisfy TypeScript, we currently use `|| ""`, even though the hook is only activated when a value is present. However, this approach has inadvertently allowed errors to occur, and we have been uncertain about how to address this properly.

This change ensures that the `|| ""` fallback in `useGetV1ProductsIdentifier` is never activated, effectively preventing the error from occurring.

src/apps/loan-list/materials/utils/digital-material-fetch-hoc.tsx

@@ -35,7 +35,13 @@ const fetchDigitalMaterial =
         data: productsData,
         isSuccess: isSuccessDigital,
         isLoading
-      } = useGetV1ProductsIdentifier(item.identifier);
+      } = useGetV1ProductsIdentifier(item.identifier, {
+        query: {
+          // We never want to pass an empty string to the API
+          // So we only enable the query if we have an isbn
+          enabled: !!item.identifier
+        }
+      });
 
       useEffect(() => {
         if (productsData && isSuccessDigital && productsData.product) {

src/components/availability-label/availability-label.tsx

@@ -1,4 +1,5 @@
 import React, { memo } from "react";
+import { first } from "lodash";
 import { useDeepCompareEffect } from "react-use";
 import { useText } from "../../core/utils/text";
 import LinkNoStyle from "../atoms/links/LinkNoStyle";
@@ -45,7 +46,7 @@ export const AvailabilityLabel: React.FC<AvailabilityLabelProps> = ({
     accessTypes,
     access,
     faustIds,
-    isbn: isbns ? isbns[0] : null,
+    isbn: first(isbns) ?? null,
     manifestText
   });
 

src/components/availability-label/useOnlineAvailabilityData.ts

@@ -22,11 +22,13 @@ const useOnlineAvailabilityData = ({
 
   // Find out if the material is cost free.
   const { isLoading: isLoadingIdentifier, data: dataIdentifier } =
+    // We never want to pass an empty string to the API
+    // So we only enable the query if we have an isbn
     useGetV1ProductsIdentifier(isbn ?? "", {
       query: {
         // Publizon / useGetV1ProductsIdentifier is responsible for online
         // materials. It requires an ISBN to do lookups.
-        enabled: enabled && isAvailable === null && isbn !== null
+        enabled: enabled && isAvailable === null && !!isbn
       }
     });
 

src/components/material/MaterialAvailabilityText/online/MaterialAvailabilityTextOnline.tsx

@@ -1,4 +1,5 @@
 import * as React from "react";
+import { first } from "lodash";
 import {
   useGetV1LibraryProfile,
   useGetV1ProductsIdentifier,
@@ -18,7 +19,16 @@ const MaterialAvailabilityTextOnline: React.FC<
   MaterialAvailabilityTextOnlineProps
 > = ({ isbns, materialType }) => {
   const t = useText();
-  const { data: productsData } = useGetV1ProductsIdentifier(isbns[0]);
+  const { data: productsData } = useGetV1ProductsIdentifier(
+    first(isbns) || "",
+    {
+      query: {
+        // We never want to pass an empty string to the API
+        // So we only enable the query if we have an isbn
+        enabled: !!first(isbns)
+      }
+    }
+  );
   const { data: libraryProfileData } = useGetV1LibraryProfile();
   const { data: loansData } = useGetV1UserLoans();