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页面对象模型

介绍​

可以通过构建大型测试套件来优化编写和维护的便捷性。页面对象模型就是一种构建测试套件的方法。

页面对象代表你的 Web 应用的一部分。例如，一个电商 Web 应用可能有一个首页、一个商品列表页和一个结算页。它们都可以用页面对象模型来表示。

页面对象通过创建适合你的应用的更高级别 API 来简化编写，并通过将元素选择器集中到一处并创建可重用代码来避免重复，从而简化维护。

实现​

我们将创建一个 PlaywrightDevPage 辅助类来封装对 playwright.dev 页面的常见操作。在内部，它将使用 page 对象。

playwright-dev-page.ts
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.net.cn');
  }

  async getStarted() {
    await this.getStartedLink.first().click();
    await expect(this.gettingStartedHeader).toBeVisible();
  }

  async pageObjectModel() {
    await this.getStarted();
    await this.pomLink.click();
  }
}

现在我们可以在测试中使用 PlaywrightDevPage 类了。

example.spec.ts
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');
});