This should make Python updates easier.

MAINT use variables for Python version rather than hardcoding it. This should make Python updates easier.

import contextlib
import inspect
from base64 import b64encode
from typing import Callable, Collection, Optional

import pytest


def _run_in_pyodide_get_source(f):
    lines, start_line = inspect.getsourcelines(f)
    num_decorator_lines = 0
    for line in lines:
        if line.startswith("def") or line.startswith("async def"):
            break
        num_decorator_lines += 1
    start_line += num_decorator_lines - 1
    # Remove first line, which is the decorator. Then pad with empty lines to fix line number.
    lines = ["\n"] * start_line + lines[num_decorator_lines:]
    return "".join(lines)


def chunkstring(string, length):
    return (string[0 + i : length + i] for i in range(0, len(string), length))


from pprint import pformat


def run_in_pyodide(
    _function: Optional[Callable] = None,
    *,
    standalone: bool = False,
    module_scope: bool = False,
    packages: Collection[str] = (),
    xfail_browsers: Optional[dict[str, str]] = None,
    driver_timeout: Optional[float] = None,
) -> Callable:
    """
    This decorator can be called in two ways --- with arguments and without
    arguments. If it is called without arguments, then the `_function` kwarg
    catches the function the decorator is applied to. Otherewise, standalone
    and packages are the actual arguments to the decorator.

    See docs/testing.md for details on how to use this.

    Parameters
    ----------
    standalone : bool, default=False
        Whether to use a standalone selenium instance to run the test or not
    packages : List[str]
        List of packages to load before running the test
    driver_timeout : Optional[float]
        selenium driver timeout (in seconds)
    """

    xfail_browsers_local = xfail_browsers or {}

    def decorator(f):
        def inner(selenium):
            if selenium.browser in xfail_browsers_local:
                xfail_message = xfail_browsers_local[selenium.browser]
                pytest.xfail(xfail_message)
            with set_webdriver_script_timeout(selenium, driver_timeout):
                if len(packages) > 0:
                    selenium.load_package(packages)
                err = None
                try:
                    # When writing the function, we set the filename to the file
                    # containing the source. This results in a more helpful
                    # traceback
                    if inspect.iscoroutinefunction(f):
                        run_python = "pyodide.runPythonAsync"
                        await_kw = "await "
                    else:
                        run_python = "pyodide.runPython"
                        await_kw = ""
                    source = _run_in_pyodide_get_source(f)
                    filename = inspect.getsourcefile(f)
                    encoded = pformat(
                        list(chunkstring(b64encode(source.encode()).decode(), 100))
                    )

                    selenium.run_js(
                        f"""
                        let eval_code = pyodide.pyodide_py.eval_code;
                        eval_code.callKwargs(
                            {{
                                source : atob({encoded}.join("")),
                                globals : pyodide._api.globals,
                                filename : {filename!r}
                            }}
                        );
                        """
                    )
                    # When invoking the function, use the default filename <eval>
                    selenium.run_js(
                        f"""{await_kw}{run_python}("{await_kw}{f.__name__}()", pyodide.globals)"""
                    )
                except selenium.JavascriptException as e:
                    err = e

            if err is not None:
                pytest.fail(
                    "Error running function in pyodide\n\n" + str(err),
                    pytrace=False,
                )

        if standalone:

            def wrapped(selenium_standalone):  # type: ignore
                inner(selenium_standalone)

        elif module_scope:

            def wrapped(selenium_module_scope):  # type: ignore
                inner(selenium_module_scope)

        else:

            def wrapped(selenium):  # type: ignore
                inner(selenium)

        return wrapped

    if _function is not None:
        return decorator(_function)
    else:
        return decorator


@contextlib.contextmanager
def set_webdriver_script_timeout(selenium, script_timeout: Optional[float]):
    """Set selenium script timeout

    Parameters
    ----------
    selenum : SeleniumWrapper
       a SeleniumWrapper wrapper instance
    script_timeout : int | float
       value of the timeout in seconds
    """
    if script_timeout is not None:
        selenium.set_script_timeout(script_timeout)
    yield
    # revert to the initial value
    if script_timeout is not None:
        selenium.set_script_timeout(selenium.script_timeout)


def parse_driver_timeout(request) -> Optional[float]:
    """Parse driver timeout value from pytest request object"""
    mark = request.node.get_closest_marker("driver_timeout")
    if mark is None:
        return None
    else:
        return mark.args[0]

import contextlib
import inspect
from base64 import b64encode
from typing import Callable, Collection, Optional

import pytest

from .common import get_make_flag

PYMAJOR = get_make_flag("PYMAJOR")
PYMINOR = get_make_flag("PYMINOR")
PYVERSION = f"python{PYMAJOR}.{PYMINOR}"


def _run_in_pyodide_get_source(f):
    lines, start_line = inspect.getsourcelines(f)
    num_decorator_lines = 0
    for line in lines:
        if line.startswith("def") or line.startswith("async def"):
            break
        num_decorator_lines += 1
    start_line += num_decorator_lines - 1
    # Remove first line, which is the decorator. Then pad with empty lines to fix line number.
    lines = ["\n"] * start_line + lines[num_decorator_lines:]
    return "".join(lines)


def chunkstring(string, length):
    return (string[0 + i : length + i] for i in range(0, len(string), length))


from pprint import pformat


def run_in_pyodide(
    _function: Optional[Callable] = None,
    *,
    standalone: bool = False,
    module_scope: bool = False,
    packages: Collection[str] = (),
    xfail_browsers: Optional[dict[str, str]] = None,
    driver_timeout: Optional[float] = None,
) -> Callable:
    """
    This decorator can be called in two ways --- with arguments and without
    arguments. If it is called without arguments, then the `_function` kwarg
    catches the function the decorator is applied to. Otherewise, standalone
    and packages are the actual arguments to the decorator.

    See docs/testing.md for details on how to use this.

    Parameters
    ----------
    standalone : bool, default=False
        Whether to use a standalone selenium instance to run the test or not
    packages : List[str]
        List of packages to load before running the test
    driver_timeout : Optional[float]
        selenium driver timeout (in seconds)
    """

    xfail_browsers_local = xfail_browsers or {}

    def decorator(f):
        def inner(selenium):
            if selenium.browser in xfail_browsers_local:
                xfail_message = xfail_browsers_local[selenium.browser]
                pytest.xfail(xfail_message)
            with set_webdriver_script_timeout(selenium, driver_timeout):
                if len(packages) > 0:
                    selenium.load_package(packages)
                err = None
                try:
                    # When writing the function, we set the filename to the file
                    # containing the source. This results in a more helpful
                    # traceback
                    if inspect.iscoroutinefunction(f):
                        run_python = "pyodide.runPythonAsync"
                        await_kw = "await "
                    else:
                        run_python = "pyodide.runPython"
                        await_kw = ""
                    source = _run_in_pyodide_get_source(f)
                    filename = inspect.getsourcefile(f)
                    encoded = pformat(
                        list(chunkstring(b64encode(source.encode()).decode(), 100))
                    )

                    selenium.run_js(
                        f"""
                        let eval_code = pyodide.pyodide_py.eval_code;
                        eval_code.callKwargs(
                            {{
                                source : atob({encoded}.join("")),
                                globals : pyodide._api.globals,
                                filename : {filename!r}
                            }}
                        );
                        """
                    )
                    # When invoking the function, use the default filename <eval>
                    selenium.run_js(
                        f"""{await_kw}{run_python}("{await_kw}{f.__name__}()", pyodide.globals)"""
                    )
                except selenium.JavascriptException as e:
                    err = e

            if err is not None:
                pytest.fail(
                    "Error running function in pyodide\n\n" + str(err),
                    pytrace=False,
                )

        if standalone:

            def wrapped(selenium_standalone):  # type: ignore
                inner(selenium_standalone)

        elif module_scope:

            def wrapped(selenium_module_scope):  # type: ignore
                inner(selenium_module_scope)

        else:

            def wrapped(selenium):  # type: ignore
                inner(selenium)

        return wrapped

    if _function is not None:
        return decorator(_function)
    else:
        return decorator


@contextlib.contextmanager
def set_webdriver_script_timeout(selenium, script_timeout: Optional[float]):
    """Set selenium script timeout

    Parameters
    ----------
    selenum : SeleniumWrapper
       a SeleniumWrapper wrapper instance
    script_timeout : int | float
       value of the timeout in seconds
    """
    if script_timeout is not None:
        selenium.set_script_timeout(script_timeout)
    yield
    # revert to the initial value
    if script_timeout is not None:
        selenium.set_script_timeout(selenium.script_timeout)


def parse_driver_timeout(request) -> Optional[float]:
    """Parse driver timeout value from pytest request object"""
    mark = request.node.get_closest_marker("driver_timeout")
    if mark is None:
        return None
    else:
        return mark.args[0]
