added error handling, fixed authenticaton, added toaster

app/server/graphql/resolvers/auth/signUp.ts

@@ -0,0 +1,33 @@
+import { IdentityContext } from '@app/server/identity';
+import { prisma, uuid } from '@app/server/prisma/client';
+import { MutationRegisterArgs } from '@generated/types';
+import bcrypt from 'bcrypt';
+
+export async function SignUpResolver(
+  _: any,
+  { input }: MutationRegisterArgs,
+  { identity }: IdentityContext
+): Promise<void> {
+  const existingUsername = await prisma.user.findUnique({
+    where: { username: input.username },
+    select: { id: true }
+  });
+  if (existingUsername != null) throw new Error('User with this username already exists.');
+
+  const existingEmail = await prisma.user.findUnique({
+    where: { email: input.email },
+    select: { id: true }
+  });
+  if (existingEmail != null) throw new Error('Email is already in use.');
+
+  const hashedPassword = await bcrypt.hash(input.password, 10);
+
+  await prisma.user.create({
+    data: {
+      id: uuid(),
+      email: input.email,
+      username: input.username,
+      password: hashedPassword
+    }
+  });
+}