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Pytest Plugin Reference

Playwright provides a Pytest plugin to write end-to-end tests. To get started with it, refer to the getting started guide.

Usage

To run your tests, use Pytest CLI.

pytest --browser webkit --headed

If you want to add the CLI arguments automatically without specifying them, you can use the pytest.ini file:

CLI arguments

  • --headed: Run tests in headed mode (default: headless).
  • --browser: Run tests in a different browser chromium, firefox, or webkit. It can be specified multiple times (default: chromium).
  • --browser-channel Browser channel to be used.
  • --slowmo Run tests with slow mo.
  • --device Device to be emulated.
  • --output Directory for artifacts produced by tests (default: test-results).
  • --tracing Whether to record a trace for each test. on, off, or retain-on-failure (default: off).
  • --video Whether to record video for each test. on, off, or retain-on-failure (default: off).
  • --screenshot Whether to automatically capture a screenshot after each test. on, off, or only-on-failure (default: off).

Fixtures

This plugin configures Playwright-specific fixtures for pytest. To use these fixtures, use the fixture name as an argument to the test function.

def test_my_app_is_working(fixture_name):
# Test using fixture_name
# ...

Function scope: These fixtures are created when requested in a test function and destroyed when the test ends.

Session scope: These fixtures are created when requested in a test function and destroyed when all tests end.

  • playwright: Playwright instance.
  • browser_type: BrowserType instance of the current browser.
  • browser: Browser instance launched by Playwright.
  • browser_name: Browser name as string.
  • browser_channel: Browser channel as string.
  • is_chromium, is_webkit, is_firefox: Booleans for the respective browser types.

Customizing fixture options: For browser and context fixtures, use the following fixtures to define custom launch options.

Parallelism: Running Multiple Tests at Once

If your tests are running on a machine with a lot of CPUs, you can speed up the overall execution time of your test suite by using pytest-xdist to run multiple tests at once:

# install dependency
pip install pytest-xdist
# use the --numprocesses flag
pytest --numprocesses auto

Depending on the hardware and nature of your tests, you can set numprocesses to be anywhere from 2 to the number of CPUs on the machine. If set too high, you may notice unexpected behavior.

See Running Tests for general information on pytest options.

Examples

Configure Mypy typings for auto-completion

# test_my_application.py
from playwright.sync_api import Page

def test_visit_admin_dashboard(page: Page):
page.goto("/admin")
# ...

Configure slow mo

Run tests with slow mo with the --slowmo argument.

pytest --slowmo 100

Skip test by browser

# test_my_application.py
import pytest

@pytest.mark.skip_browser("firefox")
def test_visit_example(page):
page.goto("https://example.com")
# ...

Run on a specific browser

# conftest.py
import pytest

@pytest.mark.only_browser("chromium")
def test_visit_example(page):
page.goto("https://example.com")
# ...

Run with a custom browser channel like Google Chrome or Microsoft Edge

pytest --browser-channel chrome
# test_my_application.py
def test_example(page):
page.goto("https://example.com")

Configure base-url

Start Pytest with the base-url argument. The pytest-base-url plugin is used for that which allows you to set the base url from the config, CLI arg or as a fixture.

pytest --base-url http://localhost:8080
# test_my_application.py
def test_visit_example(page):
page.goto("/admin")
# -> Will result in http://localhost:8080/admin

Ignore HTTPS errors

# conftest.py
import pytest

@pytest.fixture(scope="session")
def browser_context_args(browser_context_args):
return {
**browser_context_args,
"ignore_https_errors": True
}

Use custom viewport size

# conftest.py
import pytest

@pytest.fixture(scope="session")
def browser_context_args(browser_context_args):
return {
**browser_context_args,
"viewport": {
"width": 1920,
"height": 1080,
}
}

Device emulation

# conftest.py
import pytest

@pytest.fixture(scope="session")
def browser_context_args(browser_context_args, playwright):
iphone_11 = playwright.devices['iPhone 11 Pro']
return {
**browser_context_args,
**iphone_11,
}

Or via the CLI --device="iPhone 11 Pro"

Persistent context

# conftest.py
import pytest
from playwright.sync_api import BrowserType
from typing import Dict

@pytest.fixture(scope="session")
def context(
browser_type: BrowserType,
browser_type_launch_args: Dict,
browser_context_args: Dict
):
context = browser_type.launch_persistent_context("./foobar", **{
**browser_type_launch_args,
**browser_context_args,
"locale": "de-DE",
})
yield context
context.close()

When using that all pages inside your test are created from the persistent context.

Using with unittest.TestCase

See the following example for using it with unittest.TestCase. This has a limitation, that only a single browser can be specified and no matrix of multiple browsers gets generated when specifying multiple.

import pytest
import unittest

from playwright.sync_api import Page


class MyTest(unittest.TestCase):
@pytest.fixture(autouse=True)
def setup(self, page: Page):
self.page = page

def test_foobar(self):
self.page.goto("https://microsoft.com")
self.page.locator("#foobar").click()
assert self.page.evaluate("1 + 1") == 2

Debugging

Use with pdb

Use the breakpoint() statement in your test code to pause execution and get a pdb REPL.

def test_bing_is_working(page):
page.goto("https://bing.com")
breakpoint()
# ...

Deploy to CI

See the guides for CI providers to deploy your tests to CI/CD.