feat: enhance user signup process with password hashing and session management

src/lib/server/db/schema.ts

@@ -5,6 +5,7 @@ export const userTable = pgTable('user', {
 	name: text('name').notNull(),
 	email: text('email').notNull().unique(),
 	password: text('password').notNull(),
+	salt: text('salt').notNull(),
 	created_at: timestamp('created_at').defaultNow()
 });
 

src/routes/signup/+page.server.ts

@@ -1,22 +1,86 @@
 import { db } from '$lib/server/db';
-import { userTable } from '$lib/server/db/schema';
+import { userTable, sessionTable } from '$lib/server/db/schema';
+import { z } from 'zod';
+import { fail, redirect } from '@sveltejs/kit';
 import type { Actions } from './$types';
+import { randomBytes, scrypt } from 'crypto';
+
+const userSchema = z.object({
+    name: z.string().min(3, "Username must be at least 3 characters long").max(32, "Username must be at most 32 characters long"),
+    email: z.email("Invalid email address"),
+    password: z.string().min(8, "Password must be at least 8 characters long")
+});
+
+export const _hash = async (password: string, keyLength = 32): Promise<{ hash: string; salt: string }> => {
+    return new Promise((resolve, reject) => {
+        const salt = randomBytes(16).toString("hex");
+        scrypt(password, salt, keyLength, (err, derivedKey) => {
+            if (err) reject(err);
+            resolve({ hash: derivedKey.toString("hex"), salt });
+        });
+    });
+};
 
 export const actions = {
-	default: async ({ request }) => {
+    default: async ({ request, cookies }) => {
         const formData = await request.formData();
-        const name = formData.get('name');
-        const email = formData.get('email');
-		const password = formData.get('password');
+        const name = formData.get('name')?.toString();
+        const email = formData.get('email')?.toString();
+        const password = formData.get('password')?.toString();
 
-        // TODO: Implement data validation.
+        const parseResult = userSchema.safeParse({ name, email, password });
 
-        const userRecord = await db.insert(userTable).values({
-            name: name as string,
-            email: email as string,
-            password: password as string
+        if (!parseResult.success) {
+            return fail(400, {
+                data: { name, email },
+                errors: z.flattenError(parseResult.error).fieldErrors
+            });
+        }
+
+        try {
+            const hashedpw = await _hash(parseResult.data.password);
+
+            const newUser = await db.insert(userTable).values({
+                name: parseResult.data.name,
+                email: parseResult.data.email,
+                password: hashedpw.hash,
+                salt: hashedpw.salt
             }).returning();
 
-        // TODO: Handle post-signup logic (e.g., redirect, session creation).
+            const sessionToken = randomBytes(32).toString("hex");
+            const expiresAt = new Date();
+            expiresAt.setDate(expiresAt.getDate() + 7);
+
+            await db.insert(sessionTable).values({
+                user_id: newUser[0].id,
+                token: sessionToken,
+                expires_at: expiresAt
+            });
+
+            cookies.set('session', sessionToken, {
+                path: '/',
+                httpOnly: true,
+                sameSite: 'lax',
+                secure: process.env.NODE_ENV === 'production',
+                expires: expiresAt
+            });
+
+        } catch (error) {
+            if (error instanceof Error && 'code' in error && error.code === '23505') {
+                return fail(400, {
+                    data: { name, email },
+                    errors: {
+                        email: ["Email is already in use"]
+                    }
+                });
+            }
+
+            console.error("Unexpected error during user registration:", error);
+            return fail(500, {
+                message: "An unexpected error occurred."
+            });
+        }
+
+        throw redirect(303, '/dashboard');
     }
 } satisfies Actions;

src/routes/signup/+page.svelte

@@ -1,3 +1,12 @@
+<script lang="ts">
+    import { enhance } from '$app/forms';
+	import type { PageProps } from './$types';
+
+	let { form }: PageProps = $props();
+
+    /* ... */
+</script>
+
 <form method="post">
     <input type="text" name="name" placeholder="Name" required />
     <input type="email" name="email" placeholder="Email" required />