added book details, update, delete. fixes

app/server/graphql/resolvers/bookUpdateResolver.ts

@@ -0,0 +1,34 @@
+import { ensureIdentity } from '@app/server/helpers';
+import { IdentityContext } from '@app/server/identity';
+import { prisma } from '@app/server/prisma/client';
+import { Book, MutationBookUpdateArgs } from '@generated/types';
+import { toBookSchema } from './mappers/bookMapper';
+
+export async function BookUpdateResolver(
+  _: any,
+  { input }: MutationBookUpdateArgs,
+  { req, res, identity }: IdentityContext
+): Promise<Book> {
+  ensureIdentity(identity);
+
+  const model = await prisma.book.findUniqueOrThrow({
+    where: { id: input.id }
+  });
+
+  if (identity.id !== model.authorId) throw new Error('Operation is not permitted.');
+
+  if (input.title != null && input.title.length > 60) throw new Error('Title is too long.');
+  if (input.description != null && input.description.length > 900)
+    throw new Error('Description is too long.');
+
+  const modelUpdated = await prisma.book.update({
+    where: { id: input.id },
+    data: {
+      title: input.title != null ? input.title : undefined,
+      description: input.description != null ? input.description : undefined,
+      progressStatus: input.progressStatus != null ? input.progressStatus : undefined
+    }
+  });
+
+  return toBookSchema(modelUpdated, { req, res, identity });
+}