feat: setup basic error handling on server

src/server/api/routers/auth.ts

@@ -1,4 +1,5 @@
 import { z } from "zod";
+import { TRPCError } from "@trpc/server";
 
 import {
   createTRPCRouter,
@@ -12,9 +13,15 @@ import * as userRepo from "~/server/db/repository/user.repo";
 
 export const authRouter = createTRPCRouter({
   getUser: protectedProcedure.query(async ({ ctx }) => {
-    if (!ctx.user?.id) return;
+    const userId = ctx.user?.id;
 
-    const result = await userRepo.getById(ctx.db, ctx.user.id);
+    if (!userId)
+      throw new TRPCError({
+        message: `User not authenticated`,
+        code: "UNAUTHORIZED",
+      });
+
+    const result = await userRepo.getById(ctx.db, userId);
 
     return result;
   }),
@@ -33,7 +40,11 @@ export const authRouter = createTRPCRouter({
   loginWithOAuth: publicProcedure
     .input(z.object({ provider: z.string() }))
     .mutation(async ({ ctx, input }) => {
-      if (input.provider !== "google") return null;
+      if (input.provider !== "google")
+        throw new TRPCError({
+          message: `Unsupported OAuth provider: ${input.provider}`,
+          code: "BAD_REQUEST",
+        });
 
       const { data } = await ctx.db.auth.signInWithOAuth({
         provider: "google",