Page object models
Introduction
Large test suites can be structured to optimize ease of authoring and maintenance. Page object models are one such approach to structure your test suite.
A page object represents a part of your web application. An e-commerce web application might have a home page, a listings page and a checkout page. Each of them can be represented by page object models.
Page objects simplify authoring by creating a higher-level API which suits your application and simplify maintenance by capturing element selectors in one place and create reusable code to avoid repetition.
Implementation
We will create a PlaywrightDevPage
helper class to encapsulate common operations on the playwright.dev
page. Internally, it will use the page
object.
- TypeScript
- JavaScript
- Library
import { expect, type Locator, type Page } from '@playwright/test';
export class PlaywrightDevPage {
readonly page: Page;
readonly getStartedLink: Locator;
readonly gettingStartedHeader: Locator;
readonly pomLink: Locator;
readonly tocList: Locator;
constructor(page: Page) {
this.page = page;
this.getStartedLink = page.locator('a', { hasText: 'Get started' });
this.gettingStartedHeader = page.locator('h1', { hasText: 'Installation' });
this.pomLink = page.locator('li', {
hasText: 'Guides',
}).locator('a', {
hasText: 'Page Object Model',
});
this.tocList = page.locator('article div.markdown ul > li > a');
}
async goto() {
await this.page.goto('https://playwright.dev');
}
async getStarted() {
await this.getStartedLink.first().click();
await expect(this.gettingStartedHeader).toBeVisible();
}
async pageObjectModel() {
await this.getStarted();
await this.pomLink.click();
}
}
const { expect } = require('@playwright/test');
exports.PlaywrightDevPage = class PlaywrightDevPage {
/**
* @param {import('@playwright/test').Page} page
*/
constructor(page) {
this.page = page;
this.getStartedLink = page.locator('a', { hasText: 'Get started' });
this.gettingStartedHeader = page.locator('h1', { hasText: 'Installation' });
this.pomLink = page.locator('li', {
hasText: 'Guides',
}).locator('a', {
hasText: 'Page Object Model',
});
this.tocList = page.locator('article div.markdown ul > li > a');
}
async goto() {
await this.page.goto('https://playwright.dev');
}
async getStarted() {
await this.getStartedLink.first().click();
await expect(this.gettingStartedHeader).toBeVisible();
}
async pageObjectModel() {
await this.getStarted();
await this.pomLink.click();
}
};
class PlaywrightDevPage {
/**
* @param {import('playwright').Page} page
*/
constructor(page) {
this.page = page;
this.getStartedLink = page.locator('a', { hasText: 'Get started' });
this.gettingStartedHeader = page.locator('h1', { hasText: 'Installation' });
this.pomLink = page.locator('li', {
hasText: 'Playwright Test',
}).locator('a', {
hasText: 'Page Object Model',
});
this.tocList = page.locator('article div.markdown ul > li > a');
}
async getStarted() {
await this.getStartedLink.first().click();
await expect(this.gettingStartedHeader).toBeVisible();
}
async pageObjectModel() {
await this.getStarted();
await this.pomLink.click();
}
}
module.exports = { PlaywrightDevPage };
Now we can use the PlaywrightDevPage
class in our tests.
- TypeScript
- JavaScript
- Library
import { test, expect } from '@playwright/test';
import { PlaywrightDevPage } from './playwright-dev-page';
test('getting started should contain table of contents', async ({ page }) => {
const playwrightDev = new PlaywrightDevPage(page);
await playwrightDev.goto();
await playwrightDev.getStarted();
await expect(playwrightDev.tocList).toHaveText([
`How to install Playwright`,
`What's Installed`,
`How to run the example test`,
`How to open the HTML test report`,
`Write tests using web first assertions, page fixtures and locators`,
`Run single test, multiple tests, headed mode`,
`Generate tests with Codegen`,
`See a trace of your tests`
]);
});
test('should show Page Object Model article', async ({ page }) => {
const playwrightDev = new PlaywrightDevPage(page);
await playwrightDev.goto();
await playwrightDev.pageObjectModel();
await expect(page.locator('article')).toContainText('Page Object Model is a common pattern');
});
const { test, expect } = require('@playwright/test');
const { PlaywrightDevPage } = require('./playwright-dev-page');
test('getting started should contain table of contents', async ({ page }) => {
const playwrightDev = new PlaywrightDevPage(page);
await playwrightDev.goto();
await playwrightDev.getStarted();
await expect(playwrightDev.tocList).toHaveText([
`How to install Playwright`,
`What's Installed`,
`How to run the example test`,
`How to open the HTML test report`,
`Write tests using web first assertions, page fixtures and locators`,
`Run single test, multiple tests, headed mode`,
`Generate tests with Codegen`,
`See a trace of your tests`
]);
});
test('should show Page Object Model article', async ({ page }) => {
const playwrightDev = new PlaywrightDevPage(page);
await playwrightDev.goto();
await playwrightDev.pageObjectModel();
await expect(page.locator('article')).toContainText('Page Object Model is a common pattern');
});
const { PlaywrightDevPage } = require('./playwright-dev-page');
// In the test
const page = await browser.newPage();
await playwrightDev.goto();
await playwrightDev.getStarted();
await expect(playwrightDev.tocList).toHaveText([
`How to install Playwright`,
`What's Installed`,
`How to run the example test`,
`How to open the HTML test report`,
`Write tests using web first assertions, page fixtures and locators`,
`Run single test, multiple tests, headed mode`,
`Generate tests with Codegen`,
`See a trace of your tests`
]);