Running Grouped Tests Sequentially with Playwright
Testing your web application thoroughly is crucial, but managing a large test suite can be daunting. Playwright, a powerful browser automation library, provides flexibility in organizing and executing tests. Sometimes, you need to ensure that specific groups of tests run sequentially, depending on their dependencies or to avoid resource conflicts. This article will guide you through running grouped tests sequentially using Playwright.
The Problem: Sequential Test Execution
Imagine you're testing an e-commerce platform. You have a group of tests related to the "Checkout" flow, where one test depends on the previous one to have completed successfully. For instance, you might want to test adding items to the cart, proceeding to checkout, and finally, completing the purchase. Running these tests in parallel could lead to inconsistent results and errors.
Original Code: Parallel Test Execution
Let's look at a basic example of a Playwright test suite:
const { test, expect } = require('@playwright/test');
test.describe('Checkout Flow', () => {
test('Add items to cart', async ({ page }) => {
// ...add items to the cart
});
test('Proceed to checkout', async ({ page }) => {
// ...proceed to checkout page
});
test('Complete purchase', async ({ page }) => {
// ...complete the purchase
});
});
By default, Playwright runs tests in parallel to speed up the process. However, in the "Checkout Flow" scenario, these tests should run one after another.
Solution: Sequential Test Execution with test.step
Playwright offers the test.step function to execute tests sequentially within a describe block. This allows you to explicitly define the order of execution for your test groups.
const { test, expect } = require('@playwright/test');
test.describe('Checkout Flow', () => {
test.step('Add items to cart', async ({ page }) => {
// ...add items to the cart
});
test.step('Proceed to checkout', async ({ page }) => {
// ...proceed to checkout page
});
test.step('Complete purchase', async ({ page }) => {
// ...complete the purchase
});
});
This modification ensures that the tests within the "Checkout Flow" describe block execute sequentially, guaranteeing the correct order for dependent tests.
Understanding the Benefits
Using test.step provides several advantages:
- Orderly Execution: You maintain control over the test flow, preventing unexpected behavior due to parallel execution.
- Improved Test Stability: Dependent tests are guaranteed to run in the correct sequence, ensuring accurate results and eliminating potential errors.
- Enhanced Debugging: Sequential execution makes debugging much easier by allowing you to follow the test flow step-by-step.
Additional Tips
- Group Tests Logically: Organize your tests into logical groups using
test.describeblocks to clearly define related test suites. - Leverage
test.beforeEach: Usetest.beforeEachto perform setup actions for each test step, ensuring a consistent environment. - Utilize
test.afterEach: Clean up resources and reset state after each test step usingtest.afterEach.
Conclusion
Running grouped tests sequentially in Playwright is essential for ensuring accurate and reliable test results. The test.step function empowers you to define the order of execution for your tests, providing you with greater control over your test flow and promoting a more robust testing process.
Resources
By understanding the benefits of sequential test execution and applying the techniques described in this article, you can effectively manage and optimize your Playwright test suite, leading to more reliable and efficient testing practices.
