Some Useful Assertions in Playwright – Part -2

In the last part, we saw some useful assertions from Playwright. These assertions help in a lot of ways and to assert some things on the web app. Since Playwright has a rich set of features, so these assertions are also one useful addition to that armoury.

Again, the disclaimer – these assertions are provided by the default test runner given by Playwright. So we’d consider that only, not Jest.

• toHaveCount()

This assertion allows us to assert that a given locator has a exact no. of DOM nodes. A good example would be, counting the no of options from a drop down, and asserting that there are N options.

e.g.

const list = page.locator('ul > li');
await expect(list).toHaveCount(3);

Syntax :

expect(locator).toHaveCount(n);

• toHaveJSProperty()

This assertion allows to assert if a given element has a required JS Property. Note that this property can be of a primitive type as well as a plain serializable JavaScript object.

Syntax :

expect(locator).toHaveJSProperty('loaded',true);

• toHaveScreenshot()

This assertion takes two consecutive locator screenshots and then compares the last one with the expected screenshot.

Syntax :

expect(locator).toHaveScreenshot();

• toHaveText()

This assertion is useful for matching a certain DOM element if they have certain text. The assertion will assert that the locator under question points to element with the expected text.

Syntax :

expect(locator).toHaveText(expected_text);

• toHaveValue()

This assertions allows us to assert whether a given input element is having certain values. Let’s say we want to see if an input value has an integer value, then we can use this assertion

const locator = page.locator('input[type=number]');
await expect(locator).toHaveValue(/[0-9]/);

Syntax :

expect(locator).toHaveValue(expected_value);

• toHaveTitle()

This is a page level assertion and we can assert whether a given web page has a specific title,

await expect(page).toHaveTitle(expected_title);

• toHaveURL()

Asserts that the page contains the specific URL.

Syntax:

expect(page).toHaveURL(url);

• toBeOK()

Asserts that the response code of the API is under the range 200..299 status.

expect(response).toBeOK();

So these are the assertions provided in Playwright. You can use this link by LambdaTest if you want to see code pieces for all the important assertions in Playwright.