pytest_playwright.py

# Copyright (c) Microsoft Corporation.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import shutil
import os
import sys
import warnings
from typing import Any, Callable, Dict, Generator, List, Optional

import pytest
from playwright.sync_api import (
    Browser,
    BrowserContext,
    BrowserType,
    Error,
    Page,
    Playwright,
    sync_playwright,
)
from slugify import slugify
import tempfile


artifacts_folder = tempfile.TemporaryDirectory(prefix="playwright-pytest-")


@pytest.fixture(scope="session", autouse=True)
def delete_output_dir(pytestconfig: Any) -> None:
    output_dir = pytestconfig.getoption("--output")
    if os.path.exists(output_dir):
        try:
            shutil.rmtree(output_dir)
        except FileNotFoundError:
            # When running in parallel, another thread may have already deleted the files
            pass


def pytest_generate_tests(metafunc: Any) -> None:
    if "browser_name" in metafunc.fixturenames:
        browsers = metafunc.config.option.browser or ["chromium"]
        metafunc.parametrize("browser_name", browsers, scope="session")


def pytest_configure(config: Any) -> None:
    config.addinivalue_line(
        "markers", "skip_browser(name): mark test to be skipped a specific browser"
    )
    config.addinivalue_line(
        "markers", "only_browser(name): mark test to run only on a specific browser"
    )


# Making test result information available in fixtures
# https://docs.pytest.org/en/latest/example/simple.html#making-test-result-information-available-in-fixtures
@pytest.hookimpl(tryfirst=True, hookwrapper=True)
def pytest_runtest_makereport(item: Any) -> Generator[None, Any, None]:
    # execute all other hooks to obtain the report object
    outcome = yield
    rep = outcome.get_result()

    # set a report attribute for each phase of a call, which can
    # be "setup", "call", "teardown"

    setattr(item, "rep_" + rep.when, rep)


def _get_skiplist(item: Any, values: List[str], value_name: str) -> List[str]:
    skipped_values: List[str] = []
    # Allowlist
    only_marker = item.get_closest_marker(f"only_{value_name}")
    if only_marker:
        skipped_values = values
        skipped_values.remove(only_marker.args[0])

    # Denylist
    skip_marker = item.get_closest_marker(f"skip_{value_name}")
    if skip_marker:
        skipped_values.append(skip_marker.args[0])

    return skipped_values


def pytest_runtest_setup(item: Any) -> None:
    if not hasattr(item, "callspec"):
        return
    browser_name = item.callspec.params.get("browser_name")
    if not browser_name:
        return

    skip_browsers_names = _get_skiplist(
        item, ["chromium", "firefox", "webkit"], "browser"
    )

    if browser_name in skip_browsers_names:
        pytest.skip("skipped for this browser: {}".format(browser_name))


VSCODE_PYTHON_EXTENSION_ID = "ms-python.python"


@pytest.fixture(scope="session")
def browser_type_launch_args(pytestconfig: Any) -> Dict:
    launch_options = {}
    headed_option = pytestconfig.getoption("--headed")
    if headed_option:
        launch_options["headless"] = False
    elif VSCODE_PYTHON_EXTENSION_ID in sys.argv[0] and _is_debugger_attached():
        # When the VSCode debugger is attached, then launch the browser headed by default
        launch_options["headless"] = False
    browser_channel_option = pytestconfig.getoption("--browser-channel")
    if browser_channel_option:
        launch_options["channel"] = browser_channel_option
    slowmo_option = pytestconfig.getoption("--slowmo")
    if slowmo_option:
        launch_options["slow_mo"] = slowmo_option
    return launch_options


def _is_debugger_attached() -> bool:
    pydevd = sys.modules.get("pydevd")
    if not pydevd or not hasattr(pydevd, "get_global_debugger"):
        return False
    debugger = pydevd.get_global_debugger()
    if not debugger or not hasattr(debugger, "is_attached"):
        return False
    return debugger.is_attached()


def _build_artifact_test_folder(
    pytestconfig: Any, request: pytest.FixtureRequest, folder_or_file_name: str
) -> str:
    output_dir = pytestconfig.getoption("--output")
    return os.path.join(output_dir, slugify(request.node.nodeid), folder_or_file_name)


@pytest.fixture(scope="session")
def browser_context_args(
    pytestconfig: Any,
    playwright: Playwright,
    device: Optional[str],
) -> Dict:
    context_args = {}
    if device:
        context_args.update(playwright.devices[device])
    base_url = pytestconfig.getoption("--base-url")
    if base_url:
        context_args["base_url"] = base_url

    video_option = pytestconfig.getoption("--video")
    capture_video = video_option in ["on", "retain-on-failure"]
    if capture_video:
        context_args["record_video_dir"] = artifacts_folder.name

    return context_args


@pytest.fixture(scope="session")
def playwright() -> Generator[Playwright, None, None]:
    pw = sync_playwright().start()
    yield pw
    pw.stop()


@pytest.fixture(scope="session")
def browser_type(playwright: Playwright, browser_name: str) -> BrowserType:
    return getattr(playwright, browser_name)


@pytest.fixture(scope="session")
def launch_browser(
    browser_type_launch_args: Dict,
    browser_type: BrowserType,
) -> Callable[..., Browser]:
    def launch(**kwargs: Dict) -> Browser:
        launch_options = {**browser_type_launch_args, **kwargs}
        browser = browser_type.launch(**launch_options)
        return browser

    return launch


@pytest.fixture(scope="session")
def browser(launch_browser: Callable[[], Browser]) -> Generator[Browser, None, None]:
    browser = launch_browser()
    yield browser
    browser.close()
    artifacts_folder.cleanup()


@pytest.fixture
def context(
    browser: Browser,
    browser_context_args: Dict,
    pytestconfig: Any,
    request: pytest.FixtureRequest,
) -> Generator[BrowserContext, None, None]:
    pages: List[Page] = []
    context = browser.new_context(**browser_context_args)
    context.on("page", lambda page: pages.append(page))

    tracing_option = pytestconfig.getoption("--tracing")
    capture_trace = tracing_option in ["on", "retain-on-failure"]
    if capture_trace:
        context.tracing.start(
            name=slugify(request.node.nodeid),
            screenshots=True,
            snapshots=True,
            sources=True,
        )

    yield context

    # If requst.node is missing rep_call, then some error happened during execution
    # that prevented teardown, but should still be counted as a failure
    failed = request.node.rep_call.failed if hasattr(request.node, "rep_call") else True

    if capture_trace:
        retain_trace = tracing_option == "on" or (
            failed and tracing_option == "retain-on-failure"
        )
        if retain_trace:
            trace_path = _build_artifact_test_folder(pytestconfig, request, "trace.zip")
            context.tracing.stop(path=trace_path)
        else:
            context.tracing.stop()

    screenshot_option = pytestconfig.getoption("--screenshot")
    capture_screenshot = screenshot_option == "on" or (
        failed and screenshot_option == "only-on-failure"
    )
    if capture_screenshot:
        for index, page in enumerate(pages):
            human_readable_status = "failed" if failed else "finished"
            screenshot_path = _build_artifact_test_folder(
                pytestconfig, request, f"test-{human_readable_status}-{index+1}.png"
            )
            try:
                page.screenshot(timeout=5000, path=screenshot_path)
            except Error:
                pass

    context.close()

    video_option = pytestconfig.getoption("--video")
    preserve_video = video_option == "on" or (
        failed and video_option == "retain-on-failure"
    )
    if preserve_video:
        for page in pages:
            video = page.video
            if not video:
                continue
            try:
                video_path = video.path()
                file_name = os.path.basename(video_path)
                video.save_as(
                    path=_build_artifact_test_folder(pytestconfig, request, file_name)
                )
            except Error:
                # Silent catch empty videos.
                pass


@pytest.fixture
def page(context: BrowserContext) -> Generator[Page, None, None]:
    page = context.new_page()
    yield page


@pytest.fixture(scope="session")
def is_webkit(browser_name: str) -> bool:
    return browser_name == "webkit"


@pytest.fixture(scope="session")
def is_firefox(browser_name: str) -> bool:
    return browser_name == "firefox"


@pytest.fixture(scope="session")
def is_chromium(browser_name: str) -> bool:
    return browser_name == "chromium"


@pytest.fixture(scope="session")
def browser_name(pytestconfig: Any) -> Optional[str]:
    # When using unittest.TestCase it won't use pytest_generate_tests
    # For that we still try to give the user a slightly less feature-rich experience
    browser_names = pytestconfig.getoption("--browser")
    if len(browser_names) == 0:
        return "chromium"
    if len(browser_names) == 1:
        return browser_names[0]
    warnings.warn(
        "When using unittest.TestCase specifying multiple browsers is not supported"
    )
    return browser_names[0]


@pytest.fixture(scope="session")
def browser_channel(pytestconfig: Any) -> Optional[str]:
    return pytestconfig.getoption("--browser-channel")


@pytest.fixture(scope="session")
def device(pytestconfig: Any) -> Optional[str]:
    return pytestconfig.getoption("--device")


def pytest_addoption(parser: Any) -> None:
    group = parser.getgroup("playwright", "Playwright")
    group.addoption(
        "--browser",
        action="append",
        default=[],
        help="Browser engine which should be used",
        choices=["chromium", "firefox", "webkit"],
    )
    group.addoption(
        "--headed",
        action="store_true",
        default=False,
        help="Run tests in headed mode.",
    )
    group.addoption(
        "--browser-channel",
        action="store",
        default=None,
        help="Browser channel to be used.",
    )
    group.addoption(
        "--slowmo",
        default=0,
        type=int,
        help="Run tests with slow mo",
    )
    group.addoption(
        "--device", default=None, action="store", help="Device to be emulated."
    )
    group.addoption(
        "--output",
        default="test-results",
        help="Directory for artifacts produced by tests, defaults to test-results.",
    )
    group.addoption(
        "--tracing",
        default="off",
        choices=["on", "off", "retain-on-failure"],
        help="Whether to record a trace for each test.",
    )
    group.addoption(
        "--video",
        default="off",
        choices=["on", "off", "retain-on-failure"],
        help="Whether to record video for each test.",
    )
    group.addoption(
        "--screenshot",
        default="off",
        choices=["on", "off", "only-on-failure"],
        help="Whether to automatically capture a screenshot after each test.",
    )