Migrating from Protractor
Migration Principles
- No need for "webdriver-manager" / Selenium.
- Protractor’s ElementFinder ⇄ Playwright Test Locator
- Protractor’s
waitForAngular
⇄ Playwright Test auto-waiting - Don’t forget to await in Playwright Test
Cheat Sheet
Protractor | Playwright Test |
---|---|
element(by.buttonText('...')) | page.locator('button, input[type="button"], input[type="submit"] >> text="..."') |
element(by.css('...')) | page.locator('...') |
element(by.cssContainingText('..1..', '..2..')) | page.locator('..1.. >> text=..2..') |
element(by.id('...')) | page.locator('#...') |
element(by.model('...')) | page.locator('[ng-model="..."]') |
element(by.repeater('...')) | page.locator('[ng-repeat="..."]') |
element(by.xpath('...')) | page.locator('xpath=...') |
element.all | page.locator |
browser.get(url) | await page.goto(url) |
browser.getCurrentUrl() | page.url() |
Example
Protractor:
describe('angularjs homepage todo list', function() {
it('should add a todo', function() {
browser.get('https://angularjs.org');
element(by.model('todoList.todoText')).sendKeys('first test');
element(by.css('[value="add"]')).click();
const todoList = element.all(by.repeater('todo in todoList.todos'));
expect(todoList.count()).toEqual(3);
expect(todoList.get(2).getText()).toEqual('first test');
// You wrote your first test, cross it off the list
todoList.get(2).element(by.css('input')).click();
const completedAmount = element.all(by.css('.done-true'));
expect(completedAmount.count()).toEqual(2);
});
});
Line-by-line migration to Playwright Test:
const { test, expect } = require('@playwright/test'); // 1
test.describe('angularjs homepage todo list', () => {
test('should add a todo', async ({ page }) => { // 2, 3
await page.goto('https://angularjs.org'); // 4
await page.locator('[ng-model="todoList.todoText"]').fill('first test');
await page.locator('[value="add"]').click();
const todoList = page.locator('[ng-repeat="todo in todoList.todos"]'); // 5
await expect(todoList).toHaveCount(3);
await expect(todoList.nth(2)).toHaveText('first test', {
useInnerText: true,
});
// You wrote your first test, cross it off the list
await todoList.nth(2).getByRole('textbox').click();
const completedAmount = page.locator('.done-true');
await expect(completedAmount).toHaveCount(2);
});
});
Migration highlights (see inline comments in the Playwright Test code snippet):
- Each Playwright Test file has explicit import of the
test
andexpect
functions - Test function is marked with
async
- Playwright Test is given a
page
as one of its parameters. This is one of the many useful fixtures in Playwright Test. - Almost all Playwright calls are prefixed with
await
- Locator creation with page.locator() is one of the few methods that is sync.
Polyfilling waitForAngular
Playwright Test has built-in auto-waiting that makes protractor's waitForAngular
unneeded in general case.
However, it might come handy in some edge cases. Here's how to polyfill waitForAngular
function in Playwright Test:
-
Make sure you have protractor installed in your package.json
-
Polyfill function
async function waitForAngular(page) {
const clientSideScripts = require('protractor/built/clientsidescripts.js');
async function executeScriptAsync(page, script, ...scriptArgs) {
await page.evaluate(`
new Promise((resolve, reject) => {
const callback = (errMessage) => {
if (errMessage)
reject(new Error(errMessage));
else
resolve();
};
(function() {${script}}).apply(null, [...${JSON.stringify(scriptArgs)}, callback]);
})
`);
}
await executeScriptAsync(page, clientSideScripts.waitForAngular, '');
}If you don't want to keep a version protractor around, you can also use this simpler approach using this function (only works for Angular 2+):
async function waitForAngular(page) {
await page.evaluate(async () => {
// @ts-expect-error
if (window.getAllAngularTestabilities) {
// @ts-expect-error
await Promise.all(window.getAllAngularTestabilities().map(whenStable));
// @ts-expect-error
async function whenStable(testability) {
return new Promise(res => testability.whenStable(res));
}
}
});
} -
Polyfill usage
const page = await context.newPage();
await page.goto('https://example.org');
await waitForAngular(page);
Playwright Test Super Powers
Once you're on Playwright Test, you get a lot!
- Full zero-configuration TypeScript support
- Run tests across all web engines (Chrome, Firefox, Safari) on any popular operating system (Windows, macOS, Ubuntu)
- Full support for multiple origins, (i)frames, tabs and contexts
- Run tests in parallel across multiple browsers
- Built-in test artifact collection
You also get all these ✨ awesome tools ✨ that come bundled with Playwright Test:
- Playwright Inspector
- Playwright Test Code generation
- Playwright Tracing for post-mortem debugging
Further Reading
Learn more about Playwright Test runner: