import inspect
import subprocess
import sys
import textwrap
from typing import Any, Callable
def dangerously_run_function_in_subprocess(func: Callable[[], Any]) -> tuple[str, str, int]:
"""**Use with caution! This should _only_ be used with trusted code!**
Extracts a function's source and runs it in a separate subprocess. Returns stdout, stderr, and return code
from the subprocess.
This is useful for tests where an isolated environment is required.
The function to be called must not have any arguments and must not have any closures over the scope in which is was
defined.
Any modules that the function depends on must be imported inside the function.
"""
source_code = inspect.getsource(func)
dedented_source_code = textwrap.dedent(source_code)
func_name = func.__name__
script = f"""
import sys
{dedented_source_code}
if __name__ == "__main__":
{func_name}()
"""
result = subprocess.run(
[sys.executable, "-c", textwrap.dedent(script)],
capture_output=True,
text=True,
)
return result.stdout, result.stderr, result.returncode