How do I generate dynamic test cases using a CSV file and perform visual comparisons with Playwright in a React Storybook?

Answer

Step 1: Install Playwright Test for components

First, install Playwright Test for your framework by running:

npm init playwright@latest -• --ct

This command creates several files, including an index.html file for rendering components during testing.

Step 2: Read CSV file and create dynamic tests

Use a CSV file to create tests dynamically. Read the file and parse it with a CSV library. For example, if you have a CSV file named input.csv with dynamic entries, read it into your test script and loop through each entry to generate a new test case.

import { test } from '@playwright/test';
import { readFileSync } from 'fs';
import { parse } from 'csv-parse/lib/sync';

const csvData = readFileSync('input.csv', 'utf-8');
const entries = parse(csvData, { columns: true });

entries.forEach(entry => {
  test(`Test case for ${entry.name}`, async ({ page }) => {
    // Mount component, perform actions, and assert using Playwright's API
  });
});

Step 3: Perform visual comparisons

Use visual comparison tools like Pixelmatch or Resemble.js to compare screenshots of your component against expected results.

Step 4: Configure environment variables

To run tests against different environments, set environment variables through command line arguments or by using .env files. In your playwright.config.ts, define options such as baseURL based on these environment variables.

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

const config: PlaywrightTestConfig = {
  use: {
    baseURL: process.env.BASE_URL || 'https://ray.run',
  },
};

export default config;

Step 5: Run tests and generate reports

When running tests, specify output options such as outputFolder or attachmentsBaseURL depending on where you want reports and attachments saved.

By following these steps, you can create dynamic tests with Playwright Test for components and ensure your React Storybook components are functioning correctly across different environments while minimizing manual testing efforts.