fixed errors and finish endpoints

BookHive/Specifications/Loans/GetAvailableBookByIdSpec.cs

@@ -0,0 +1,13 @@
+using Ardalis.Specification;
+using BookHive.Models;
+
+namespace BookHive.Specifications.Loans;
+
+public class GetAvailableBookByIdSpec : Specification<Loan>
+{
+    public GetAvailableBookByIdSpec(int bookId)
+    {
+        Query
+            .Where(x => x.BookId == bookId && x.ReturnDate == null);
+    }
+}

BookHive/Specifications/Reviews/GetReviewByCriteriaSpec.cs

@@ -0,0 +1,13 @@
+using Ardalis.Specification;
+using BookHive.Models;
+
+namespace BookHive.Specifications.Reviews;
+
+public class GetReviewByCriteriaSpec : SingleResultSpecification<Review>
+{
+    public GetReviewByCriteriaSpec(int bookId, int memberId)
+    {
+        Query
+            .Where(x => x.BookId == bookId && x.MemberId == memberId);
+    }
+}