import ast

import pathlib

from collections import defaultdict

class RaiseFromNoneVisitor(ast.NodeVisitor):

line_numbers = defaultdict(list)

def __init__(self, filename):

self.filename = filename

def visit_Raise(self, node: ast.Raise):

if node.cause is not None:

if isinstance(node.cause, ast.Constant) and node.cause.value is None:

RaiseFromNoneVisitor.line_numbers[self.filename].append(node.lineno)

self.generic_visit(node)

def scan_file(module_path: pathlib.Path):

source = pathlib.Path(module_path).read_text(encoding="utf-8")

tree = ast.parse(source, filename=module_path)

RaiseFromNoneVisitor(module_path).visit(tree)

def walk_package_modules():

for p in pathlib.Path("sentry_sdk").rglob("*.py"):

yield p

def format_detected_raises(line_numbers) -> str:

lines = []

for filepath, line_numbers_in_file in line_numbers.items():

lines_string = ", ".join(f"line {ln}" for ln in sorted(line_numbers_in_file))

lines.append(

f"{filepath}: {len(line_numbers_in_file)} occurrence(s) at {lines_string}"

)

return "\n".join(lines)

def main():

for module_path in walk_package_modules():

scan_file(module_path)

# TODO: Investigate why we suppress exception chains here.

ignored_raises = {

pathlib.Path("sentry_sdk/integrations/asgi.py"): 2,

pathlib.Path("sentry_sdk/integrations/asyncio.py"): 1,

}

raise_from_none_count = {

file: len(occurences)

for file, occurences in RaiseFromNoneVisitor.line_numbers.items()

}

if raise_from_none_count != ignored_raises:

exc = Exception("Detected unexpected raise ... from None.")

exc.add_note(

"Raise ... from None suppresses chained exceptions, removing valuable context."

)

exc.add_note(format_detected_raises(RaiseFromNoneVisitor.line_numbers))

raise exc

if __name__ == "__main__":

main()