improve: the registration API

packages/backend/register.ts

@@ -1,27 +1,65 @@
 import { createHandlers } from "./utils.ts";
 import Argon2id from "@rabbit-company/argon2id";
+import { object, string, ValidationError } from "yup";
+import type { Context } from "hono";
+import type { Bindings, BlankEnv, BlankInput } from "hono/types";
+import type { Client } from "https://deno.land/x/postgres@v0.19.3/mod.ts";
 
-export const registerHandler = createHandlers(async (c) => {
-	try {
-		const client = c.get("dbCred");
-		const body = await c.req.json();
-		const username = body.username;
-		const password = body.password;
-		const hash = await Argon2id.hashEncoded(password);
+const RegistrationBodySchema = object({
+	username: string().trim().required("Username is required").max(50, "Username cannot exceed 50 characters"),
+	password: string().required("Password is required"),
+    nickname: string().optional(),
+});
+
+type ContextType = Context<BlankEnv & { Bindings: Bindings }, "/user", BlankInput>;
+
+export const userExists = async (username: string, client: Client) => {
 	const query = `
-            INSERT INTO users (username, password) VALUES ($1, $2)
+        SELECT * FROM users WHERE username = $1
     `;
-		await client.queryObject(query, [username, hash]);
+	const result = await client.queryObject(query, [username]);
+	return result.rows.length > 0;
+}
+
+export const registerHandler = createHandlers(async (c: ContextType) => {
+	const client = c.get("dbCred");
+
+	try {
+		const body = await RegistrationBodySchema.validate(await c.req.json());
+		const { username, password, nickname } = body;
+
+        if (await userExists(username, client)) {
 			return c.json({
-			success: true,
-			message: "Registered",
-		});
+				message: `User "${username}" already exists.`,
+			}, 400);
+        }
+
+		const hash = await Argon2id.hashEncoded(password);
+
+		const query = `
+            INSERT INTO users (username, password, nickname) VALUES ($1, $2, $3)
+        `;
+		await client.queryObject(query, [username, hash, nickname || null]);
+
+		return c.json({
+			message: `User "${username}" registered successfully.`,
+		}, 201);
 	} catch (e) {
-        if (e instanceof SyntaxError) {
-            return c.json({ error: "Invalid JSON" }, 400);
-        }
-		else {
-            return c.json({ error: (e as Error).message }, 500);
+		if (e instanceof ValidationError) {
+			return c.json({
+				message: "Invalid registration data.",
+				errors: e.errors,
+			}, 400); 
+		} else if (e instanceof SyntaxError) {
+			return c.json({
+				message: "Invalid JSON in request body.",
+			}, 400);
+		} else {
+			console.error("Registration error:", e);
+			return c.json({
+				message: "An unexpected error occurred during registration.",
+				error: (e as Error).message,
+			}, 500);
 		}
 	}
 });