nocodb/packages/noco-docs/content/en/engineering/playwright.md

title	description	position	category	menuTitle
Playwright	Overview to playwright based e2e tests	3250	Engineering	Testing

How to run tests

All the tests reside in tests/playwright folder.

Make sure to install the dependencies(in the playwright folder):

npm install
npx playwright install chromium --with-deps

Run Test Server

Start the backend test server (in packages/nocodb folder):

npm run watch:run:playwright

Start the frontend test server (in packages/nc-gui folder):

NUXT_PAGE_TRANSITION_DISABLE=true npm run dev

Running all tests

For selecting db type, rename .env.example to .env and set E2E_DEV_DB_TYPE to sqlite(default), mysql or pg.

headless mode(without opening browser):

npm run test

with browser:

npm run test:debug

For setting up mysql:

docker-compose -f ./tests/playwright/scripts/docker-compose-mysql-playwright.yml  up -d

For setting up postgres:

docker-compose -f ./tests/playwright/scripts/docker-compose-playwright-pg.yml 

Running individual tests

Add .only to the test you want to run:

test.only('should login', async ({ page }) => {
  // ...
})

npm run test

Concepts

Independent tests

• All tests are independent of each other.
• Each test starts with a fresh project with a fresh sakila database(option to not use sakila db is also there).
• Each test creates a new user and logs in with that user.

Caveats:

• Some stuffs are shared i.e, users, plugins etc. So be catious while writing tests. A fix for this is in the works.
• In test, we prefix email and project with its id, which will be deleted after the test is done.

What to test

• UI verification. This includes verifying the state of the UI element, i.e if the element is visible, if the element has a particular text etc.
• Test should verify a user flow. A test has a default timeout of 60 seconds. If a test is taking more than 60 seconds, it is a sign that the test should be broken down into smaller tests
• Deciding what todo: add more

Playwright

• Playwright is a nodejs library for automating chromium, firefox and webkit.
• For each test, a new browser context is created. This means that each test runs in a new incognito window. In test page is provided by playwright where you can do all the actions.
• For assertion always use expect from @playwright/test library. This library provides a lot of useful assertions, which also has retry logic built in.

Page Objects

• Page objects are used to abstract over the components/page. This makes the tests more readable and maintainable.
• All page objects are in tests/playwright/pages folder.
• All the test related code should be in page objects. This makes the tests more readable and maintainable.
• Methods should be as thin as possible and its better to have multiple methods than one big method, which improves reusability.

The methods of a page object can be classified into 2 categories:

• Actions: Performs an UI actions like click, type, select etc. Is also responsible for waiting for the element to be ready and the action to be performed. This included waiting for api calls to complete.
• Assertions: Asserts the state of the UI element, i.e if the element is visible, if the element has a particular text etc. Use expect from @playwright/test and if not use expect.poll to wait for the assertion to pass.

Writing a test

Let's write a test for testing filter functionality.

For simplicity, we will have DashboardPage implemented, which will have all the methods related to dashboard page and also its child components like Grid, etc.

Create a test suite

Create a new file filter.spec.ts in tests/playwright/tests folder and use setup method to create a new project and user.

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

test.describe('Filter', () => {
  let context: NcContext;

  test.beforeEach(async ({ page }) => {
    context = await setup({ page });
  })

  test('should filter', async ({ page }) => {
    // ...
  });
});

Create a page object

Since filter is UI wise scoped to a Toolbar , we will add filter page object to ToolbarPage page object.

export class ToolbarPage extends BasePage {
  readonly parent: GridPage | GalleryPage | FormPage | KanbanPage;
  readonly filter: ToolbarFilterPage;

  constructor(parent: GridPage | GalleryPage | FormPage | KanbanPage) {
    super(parent.rootPage);
    this.parent = parent;
    this.filter = new ToolbarFilterPage(this);
  }
}

We will create ToolbarFilterPage page object, which will have all the methods related to filter.

export class ToolbarFilterPage extends BasePage {
  readonly toolbar: ToolbarPage;

  constructor(toolbar: ToolbarPage) {
    super(toolbar.rootPage);
    this.toolbar = toolbar;
  }
}

Here BasePage is an abstract class, which used to enforce structure for all page objects. Thus all page object should inherit BasePage.

• Common methods like waitForResponse and getClipboardText.
• Provides structure for page objects, enforces all Page objects to have rootPage property, which is the root page object of the test.
• Enforces all pages to have a get method which will return the locator of the main container of that page, hence we can have focused dom selection, i.e.

// This will only select the button inside the container of the concerned page
await this.get().querySelector('button').count();

Writing an action method

This a method which will reset/clear all the filters. Since this is an action method, it will also wait for the delete filter api to return. Ignoring this api call will cause flakiness in the test, down the line.

async resetFilter() {
  await this.waitForResponse({
    uiAction: this.get().locator('.nc-filter-item-remove-btn').click(),
    httpMethodsToMatch: ['DELETE'],
    requestUrlPathToMatch: '/api/v1/db/meta/filters/',
  });
}

Writing an assertion/verification method

Here we use expect from @playwright/test library, which has retry logic built in.

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

async verifyFilter({ title }: { title: string }) {
  await expect(
    this.get().locator(`[data-testid="nc-fields-menu-${title}"]`).locator('input[type="checkbox"]')
  ).toBeChecked();
}

Tips to avoid flakiness

• If an ui action, causes an api call or the UI state change, then wait for that api call to complete or the UI state to change.
• What to wait out can be situation specific, but in general, is best to wait for the final state to be reached, i.e. in the case of creating filter, while it seems like waiting for the filter api to complete is enough, but after its return the table rows are reloaded and the UI state changes, so its better to wait for the table rows to be reloaded.