SlugShare uses a simple points system to track each user’s dining hall points balance. Users can manually update their balance, and points are automatically transferred when requests are accepted.
Points Model
Each user has a one-to-one relationship with a Points record in the database:
model Points {
id String @id @default(cuid())
userId String @unique
balance Int @default(0)
user User @relation(fields: [userId], references: [id], onDelete: Cascade)
updatedAt DateTime @updatedAt
}
Points records are created on-demand using the upsert pattern. If a user doesn’t have a Points record yet, one is automatically created when they access their dashboard or update their balance.
Viewing Points Balance
Users can view their current points balance on the dashboard:
Navigate to dashboard
After signing in, users are automatically redirected to /dashboard.
Dashboard fetches points balance
The dashboard page uses the upsert pattern to get or create the user’s Points record:const points = await prisma.points.upsert({
where: { userId: user.id },
update: {},
create: {
userId: user.id,
balance: 0,
},
});
Display balance
The current balance is displayed prominently in a card:<CardContent className="space-y-4">
<p className="text-4xl font-bold text-blue-600">{points.balance}</p>
<UpdatePointsForm currentBalance={points.balance} />
</CardContent>
Updating Points Balance
Users can manually update their dining hall points balance to reflect their actual account:
Enter new balance
Users enter their current points balance in the update form on the dashboard.The balance must be a non-negative number. Negative balances are not allowed.
Submit to API
The form sends a POST request to /api/points with the new balance:const response = await fetch("/api/points", {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({ balance: newBalance }),
});
Validate and update
The API validates the balance and updates the Points record:export async function POST(request: NextRequest) {
const user = await getCurrentUser();
if (!user || !user.id) {
return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
}
const { balance } = await request.json();
if (typeof balance !== "number" || balance < 0) {
return NextResponse.json(
{ error: "Balance must be a non-negative number" },
{ status: 400 }
);
}
const points = await prisma.points.upsert({
where: { userId: user.id },
update: { balance },
create: { userId: user.id, balance },
});
return NextResponse.json({ balance: points.balance });
}
Refresh dashboard
After successful update, the dashboard refreshes to show the new balance.
Automatic Points Transfer
When a user accepts a request to donate points, SlugShare automatically transfers points between accounts using a database transaction:
app/api/requests/[id]/accept/route.ts
await prisma.$transaction([
// Decrease donor's balance
prisma.points.update({
where: { userId: user.id },
data: {
balance: {
decrement: request.pointsRequested,
},
},
}),
// Increase requester's balance
prisma.points.update({
where: { userId: request.requesterId },
data: {
balance: {
increment: request.pointsRequested,
},
},
}),
// Update request status
prisma.request.update({
where: { id: requestId },
data: {
status: "accepted",
donorId: user.id,
},
}),
]);
Using prisma.$transaction() ensures atomicity. If any operation fails, all changes are rolled back to prevent data inconsistency.
Balance Validation
Before accepting a request, SlugShare validates that the donor has sufficient points:
export function validateAcceptRequest(
request: { pointsRequested: number } | null,
userId: string,
donorBalance: number
): ValidationResult {
if (donorBalance < request.pointsRequested) {
return {
valid: false,
error: "Insufficient points balance",
status: 400
};
}
return { valid: true };
}
Users cannot accept requests if they don’t have enough points. The system prevents overdrafts to maintain accurate balances.
Fetching Points via API
To retrieve a user’s current points balance programmatically:
const response = await fetch("/api/points");
const { balance } = await response.json();
export async function GET() {
const user = await getCurrentUser();
if (!user || !user.id) {
return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
}
const points = await prisma.points.upsert({
where: { userId: user.id },
update: {},
create: { userId: user.id, balance: 0 },
});
return NextResponse.json({ balance: points.balance });
}
Upsert Pattern
SlugShare consistently uses the upsert pattern to handle Points records. This prevents errors when a user’s Points record doesn’t exist:
const points = await prisma.points.upsert({
where: { userId: user.id },
update: {}, // or { balance: newBalance } to update
create: { userId: user.id, balance: 0 },
});
- Points records are created lazily (only when needed)
- Prevents “record not found” errors
- Handles first-time users automatically
- Simplifies API logic