How to Run Tests in TaxHacker: Setting Up Automated Testing for the Next.js Codebase

TaxHacker does not ship with a built-in test suite, so you must manually install and configure a testing framework like Jest or Playwright before you can run any automated tests.

The vas3k/TaxHacker repository is a Next.js application that currently relies on manual testing and ESLint for code quality. If you are looking to run tests in TaxHacker, you first need to understand that the project lacks predefined test scripts or test files. This guide explains the current verification options available and provides complete setup instructions for adding both unit and end-to-end testing capabilities.

Why TaxHacker Has No Default Test Command

Examining the package.json file reveals that the project defines only four npm scripts: dev, build, start, and lint.

{
  "scripts": {
    "dev": "next dev -p 7331 --turbopack",
    "build": "next build",
    "start": "prisma migrate deploy && next start",
    "lint": "next lint"
  }
}

There are no test or e2e entries in the scripts section. Additionally, the source tree contains no files matching standard test patterns such as *.test.ts, *.spec.ts, or *.test.tsx. While package-lock.json lists @playwright/test as a dev-dependency, the repository lacks both a playwright.config.ts configuration file and an actual Playwright test directory.

Current Verification: Running the Linter

The only automated quality check available out of the box is the Next.js ESLint integration. To run static analysis across the codebase, use the built-in lint script:

npm run lint

This command executes next lint and checks for JavaScript and TypeScript errors according to the project's ESLint configuration. While this catches syntax issues and style violations, it does not verify runtime behavior or business logic.

Adding Unit Tests with Jest

To implement unit testing in TaxHacker, you need to install Jest and its TypeScript preset manually. Since the project uses TypeScript, ts-jest is the recommended preset for handling *.ts and *.tsx files.

First, install the required dev dependencies:

npm i -D jest ts-jest @types/jest

Create a jest.config.ts file in the project root:

export default {
  preset: 'ts-jest',
  testEnvironment: 'node',
  moduleFileExtensions: ['ts', 'tsx', 'js', 'json'],
  testMatch: ['**/?(*.)+(spec|test).[tj]s?(x)'],
};

Add the test script to your package.json:

{
  "scripts": {
    "test": "jest --detectOpenHandles"
  }
}

Place your test files alongside the source code you want to test, such as models/users.test.ts, then execute:

npm run test

Adding End-to-End Tests with Playwright

Because @playwright/test already exists in the lock file, you only need to install the browser binaries and create a configuration to run end-to-end tests in TaxHacker.

Install the Playwright browsers:

npx playwright install

Create a minimal playwright.config.ts:

import { defineConfig } from '@playwright/test';

export default defineConfig({
  testDir: 'e2e',
  webServer: {
    command: 'npm run dev',
    port: 7331,
    timeout: 120 * 1000,
    reuseExistingServer: !process.env.CI,
  },
});

Create a sample test file at e2e/home.spec.ts:

import { test, expect } from '@playwright/test';

test('homepage loads', async ({ page }) => {
  await page.goto('http://localhost:7331');
  await expect(page).toHaveTitle(/TaxHacker/);
});

Run the Playwright suite:

npx playwright test

Verifying Database Schema Integrity

Although not a traditional test runner, you can verify database migration integrity using the Prisma CLI, which is already included as a dev dependency. This ensures your prisma/schema.prisma definitions align with the database state:

npx prisma migrate dev

This command is particularly useful during development to catch schema drift before deploying the application.

Summary

• TaxHacker has no built-in test suite: The package.json contains no test scripts and the repository lacks *.test.ts files.
• Linting is available immediately: Run npm run lint to execute Next.js ESLint for static code analysis.
• Add Jest for unit testing: Install jest and ts-jest, create a jest.config.ts, and add a test script to run unit tests.
• Leverage existing Playwright: Since Playwright is already in package-lock.json, you only need to install browsers and create a config to enable end-to-end testing.
• Prisma validates schemas: Use npx prisma migrate dev to verify database integrity as part of your quality workflow.

Frequently Asked Questions

Does TaxHacker come with any pre-written tests?

No, the repository does not contain any pre-written tests. According to the source code in package.json, there are no test scripts defined, and no files matching *.test.ts or *.spec.ts patterns exist in the codebase. You must implement your own test suite from scratch.

Can I run tests without installing additional dependencies?

No, you cannot run automated tests without installing additional dependencies. The only verification command available without extra packages is npm run lint, which performs static analysis. To execute actual unit or integration tests, you must install a testing framework like Jest or Playwright.

Why is Playwright listed in package-lock.json but not configured?

The package-lock.json file shows that @playwright/test was previously added as a dev-dependency, but the project maintainers did not commit a playwright.config.ts file or any test specifications. You can activate it by installing the browser binaries with npx playwright install and creating the necessary configuration files.

What is the fastest way to add testing to TaxHacker?

The fastest approach is to install Jest for unit testing. Run npm i -D jest ts-jest @types/jest, create a basic jest.config.ts, and add "test": "jest" to the scripts section of package.json. This setup takes less than five minutes and allows you to immediately start writing tests for utilities and models.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}