See the discussion on #2174. An uncaught C++ error on main causes an error like:
```
TypeError: Cannot create property 'pyodide_fatal_error' on number '28811048'
```
With this the same error looks like:
```
Pyodide has suffered a fatal error. Please report this to the Pyodide maintainers.
The cause of the fatal error was:
CppException: Unable to cast Python instance to C++ type (compile in debug mode for details)
```
Support for C++ exceptions in packages. See the discussion on #2174. An uncaught C++ error on main causes an error like:
```
TypeError: Cannot create property 'pyodide_fatal_error' on number '28811048'
```
With this the same error looks like:
```
Pyodide has suffered a fatal error. Please report this to the Pyodide maintainers.
The cause of the fatal error was:
CppException: Unable to cast Python instance to C++ type (compile in debug mode for details)
```
import pytest
import os
from pathlib import Path
from typing import List, Dict
import functools
import json

from pyodide_build.io import parse_package_config
from conftest import built_packages, ROOT_PATH

PKG_DIR = ROOT_PATH / "packages"


@functools.cache
def registered_packages() -> List[str]:
    """Returns a list of registered package names"""
    packages = []
    for name in os.listdir(PKG_DIR):
        if (PKG_DIR / name).is_dir() and (PKG_DIR / name / "meta.yaml").exists():
            packages.append(name)
    return packages


def registered_packages_meta():
    """Returns a dictionary with the contents of `meta.yaml`
    for each registered package
    """
    packages = registered_packages
    return {
        name: parse_package_config(PKG_DIR / name / "meta.yaml") for name in packages
    }


UNSUPPORTED_PACKAGES: Dict[str, List[str]] = {
    "chrome": [],
    "firefox": [],
    "node": [],
}
if "CI" in os.environ:
    UNSUPPORTED_PACKAGES["chrome"].extend(["statsmodels"])


@pytest.mark.parametrize("name", registered_packages())
def test_parse_package(name):
    # check that we can parse the meta.yaml
    meta = parse_package_config(PKG_DIR / name / "meta.yaml")

    skip_host = meta.get("build", {}).get("skip_host", True)
    if name == "numpy":
        assert skip_host is False
    elif name == "pandas":
        assert skip_host is True


@pytest.mark.skip_refcount_check
@pytest.mark.driver_timeout(40)
@pytest.mark.parametrize("name", registered_packages())
def test_import(name, selenium_standalone):
    if name not in built_packages():
        raise AssertionError(
            "Implementation error. Test for an unbuilt package "
            "should have been skipped in selenium_standalone fixture"
        )

    meta = parse_package_config(PKG_DIR / name / "meta.yaml")

    if name in UNSUPPORTED_PACKAGES[selenium_standalone.browser]:
        pytest.xfail(
            "{} fails to load and is not supported on {}.".format(
                name, selenium_standalone.browser
            )
        )

    selenium_standalone.run("import glob, os")

    baseline_pyc = selenium_standalone.run(
        """
        len(list(glob.glob(
            '/lib/python3.9/site-packages/**/*.pyc',
            recursive=True)
        ))
        """
    )
    for import_name in meta.get("test", {}).get("imports", []):
        selenium_standalone.run_async("import %s" % import_name)
        # Make sure that even after importing, there are no additional .pyc
        # files
        assert (
            selenium_standalone.run(
                """
                len(list(glob.glob(
                    '/lib/python3.9/site-packages/**/*.pyc',
                    recursive=True)
                ))
                """
            )
            == baseline_pyc
        )
        # Make sure no exe files were loaded!
        assert (
            selenium_standalone.run(
                """
                len(list(glob.glob(
                    '/lib/python3.9/site-packages/**/*.exe',
                    recursive=True)
                ))
                """
            )
            == 0
        )

import pytest
import os
from pathlib import Path
from typing import List, Dict
import functools
import json

from pyodide_build.io import parse_package_config
from conftest import built_packages, ROOT_PATH

PKG_DIR = ROOT_PATH / "packages"


@functools.cache
def registered_packages() -> List[str]:
    """Returns a list of registered package names"""
    packages = []
    for name in os.listdir(PKG_DIR):
        if (PKG_DIR / name).is_dir() and (PKG_DIR / name / "meta.yaml").exists():
            packages.append(name)
    return packages


def registered_packages_meta():
    """Returns a dictionary with the contents of `meta.yaml`
    for each registered package
    """
    packages = registered_packages
    return {
        name: parse_package_config(PKG_DIR / name / "meta.yaml") for name in packages
    }


UNSUPPORTED_PACKAGES: Dict[str, List[str]] = {
    "chrome": [],
    "firefox": [],
    "node": [],
}
if "CI" in os.environ:
    UNSUPPORTED_PACKAGES["chrome"].extend(["statsmodels"])


@pytest.mark.parametrize("name", registered_packages())
def test_parse_package(name):
    # check that we can parse the meta.yaml
    meta = parse_package_config(PKG_DIR / name / "meta.yaml")

    skip_host = meta.get("build", {}).get("skip_host", True)
    if name == "numpy":
        assert skip_host is False
    elif name == "pandas":
        assert skip_host is True


@pytest.mark.skip_refcount_check
@pytest.mark.driver_timeout(40)
@pytest.mark.parametrize("name", registered_packages())
def test_import(name, selenium_standalone):
    if name not in built_packages():
        raise AssertionError(
            "Implementation error. Test for an unbuilt package "
            "should have been skipped in selenium_standalone fixture"
        )

    meta = parse_package_config(PKG_DIR / name / "meta.yaml")

    if name in UNSUPPORTED_PACKAGES[selenium_standalone.browser]:
        pytest.xfail(
            "{} fails to load and is not supported on {}.".format(
                name, selenium_standalone.browser
            )
        )

    selenium_standalone.run("import glob, os")

    baseline_pyc = selenium_standalone.run(
        """
        len(list(glob.glob(
            '/lib/python3.9/site-packages/**/*.pyc',
            recursive=True)
        ))
        """
    )
    for import_name in meta.get("test", {}).get("imports", []):
        selenium_standalone.run_async("import %s" % import_name)
        # Make sure that even after importing, there are no additional .pyc
        # files
        assert (
            selenium_standalone.run(
                """
                len(list(glob.glob(
                    '/lib/python3.9/site-packages/**/*.pyc',
                    recursive=True)
                ))
                """
            )
            == baseline_pyc
        )
        # Make sure no exe files were loaded!
        assert (
            selenium_standalone.run(
                """
                len(list(glob.glob(
                    '/lib/python3.9/site-packages/**/*.exe',
                    recursive=True)
                ))
                """
            )
            == 0
        )
