End-to-End Testing a Fullstack Next.js + Prisma App

Sep 30, 2025 |

9 minutes read

E2E Testing in Next.js + Prisma Applications

Modern web applications are rarely just a collection of frontend pages. They are dynamic systems where user interactions trigger API calls, update data in a database, and reflect changes back on the interface in real time. For developers building with Next.js—a framework that unifies frontend and backend logic—and Prisma—a type-safe ORM for database access—the complexity of these workflows increases.

While unit tests validate isolated components and integration tests ensure specific modules interact properly, they cannot fully guarantee that the entire system works correctly when combined. This is where End-to-End (E2E) testing becomes critical.

E2E testing simulates real user actions, from filling out forms to triggering backend APIs and verifying data persistence. With tools like Playwright and Cypress, developers can automate these flows and gain confidence that their app behaves as expected in production-like scenarios.

In this article, we’ll walk through how to set up and run E2E tests in a fullstack Next.js + Prisma application. We’ll explore the challenges of skipping E2E tests, demonstrate a step-by-step solution with real code examples, and wrap up with best practices to ensure testing reliability.

A user visits a signup page and enters their details.
The frontend sends the data to an API route.
The database confirms the change, and the UI updates with a welcome message.

While this seems straightforward, issues often arise:

The frontend may not correctly handle API errors.
The API route could fail to validate inputs.
The Prisma query might throw errors or fail silently.
The UI could display an incorrect state if the database doesn’t update properly.

Unit and integration tests might confirm that the signup form submits and that Prisma can insert a user, but they cannot validate the entire journey from browser to database and back. Without E2E tests, it’s possible to ship code that passes lower-level tests but still breaks in production.

Step 1: Setting Up Prisma with Next.js

`
Install Prisma and initialize it: 
bash[Text Wrapping Break]npm install @prisma/client[Text Wrapping Break]npm install -D prisma[Text Wrapping Break]npx prisma init[Text Wrapping Break] 
Example Prisma schema: 
datasource db { 
  provider = "postgresql" 
  url  	= env("database_url") 
} 
generator client { 
  provider = "prisma-client-js" 
} 
model User { 
  id	Int 	@id @default(autoincrement()) 
  email String  @unique 
  name  String? 
}

Step 2: Setting Up E2E Testing (Playwright)

Install Playwright:

`
bash[Text Wrapping Break]npm install -D @playwright/test[Text Wrapping Break]npx playwright install[Text Wrapping Break] 
Example test file: 
javascript[Text Wrapping Break]// tests/user.spec.ts[Text Wrapping Break]import { test, expect } from '@playwright/test';[Text Wrapping Break][Text Wrapping Break]test('User signup flow works', async ({ page }) => {[Text Wrapping Break]  await page.goto('http://localhost:3000/signup');[Text Wrapping Break]  await page.fill('input[name="email"]', 'test@example.com');[Text Wrapping Break]  await page.fill('input[name="name"]', 'Test User');[Text Wrapping Break]  await page.click('button[type="submit"]');[Text Wrapping Break]  await expect(page.locator('h1')).toContainText('Welcome, Test User');[Text Wrapping Break]});[Text Wrapping Break]

Step 3: Database Testing with Prisma

You can directly validate database state in tests using Prisma Client. This ensures that UI actions are correctly reflected in the database.

`
javascript[Text Wrapping Break]// tests/db.spec.ts[Text Wrapping Break]import { PrismaClient } from '@prisma/client';[Text Wrapping Break]const prisma = new PrismaClient();[Text Wrapping Break][Text Wrapping Break]test('User is saved to the database', async () => {[Text Wrapping Break]  const user = await prisma.user.findUnique({ where: { email: 'test@example.com' } });[Text Wrapping Break]  expect(user).not.toBeNull();[Text Wrapping Break]});

Best Practices / Recommendations

Use a Dedicated Test Database[Text Wrapping Break]• Seed and Reset Data[Text Wrapping Break]• Combine UI and DB Assertions[Text Wrapping Break]• Run E2E Tests in CI/CD[Text Wrapping Break]• Balance with Unit and Integration Tests
Leverage Parallelization[Text Wrapping Break]• Secure Authentication Flows[Text Wrapping Break]• Add Visual Regression Testing

Next.js + Prisma: Master E2E Testing with Confidence

The Way Forward

End-to-end testing bridges the gap between isolated tests and real-world reliability. In a Next.js + Prisma stack, where the frontend, backend, and database are tightly integrated, E2E testing ensures that:

UI interactions reflect correctly in the database
API routes handle requests and errors consistently.
Authentication and authorization remain secure.
Regression bugs are caught before reaching users.

By automating workflows with Playwright or Cypress, teams can reduce manual QA, ship features with confidence, and scale development without compromising stability. As projects grow, extending tests with Dockerized environments and visual regression checks further strengthens reliability.

In short, E2E testing is not just a safeguard—it’s an enabler of faster iteration, higher-quality releases, and better user experiences.