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页面对象模型

介绍​

¥Introduction

可以构建大型测试套件以优化创作和维护的便利性。页面对象模型是构建测试套件的一种方法。

¥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.

页面对象代表 Web 应用的一部分。电商 Web 应用可能有主页、列表页面和结账页面。它们中的每一个都可以由页面对象模型来表示。

¥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.

页面对象通过创建适合你的应用的更高级别 API 来简化创作，通过在一处捕获元素选择器并创建可重用代码以避免重复来简化维护。

¥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.

执行​

¥Implementation

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

¥We will create a PlaywrightDevPage helper class to encapsulate common operations on the playwright.dev page. Internally, it will use the page object.

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.nodejs.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。

¥Now we can use the PlaywrightDevPage class in our tests.

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');
});