stubgen: Add flagfile support (#18061)

KapJI · web-flow · commit 06a566b81993 · 2024-10-28T11:17:42.000-07:00
## Description This is already supported by main `mypy` binary and `dmypy` but not by `stubgen`. ## Context I maintain https://github.com/KapJI/homeassistant-stubs which automatically generates typing stubs. Currently list of arguments there is 50 KB long and this can be longer that supported by OS (depending on configuration). It'd help to write these args to flagfile.
diff --git a/mypy/stubgen.py b/mypy/stubgen.py
@@ -1793,7 +1793,9 @@ def generate_stubs(options: Options) -> None:
 
 
 def parse_options(args: list[str]) -> Options:
-    parser = argparse.ArgumentParser(prog="stubgen", usage=HEADER, description=DESCRIPTION)
+    parser = argparse.ArgumentParser(
+        prog="stubgen", usage=HEADER, description=DESCRIPTION, fromfile_prefix_chars="@"
+    )
 
     parser.add_argument(
         "--ignore-errors",
