check dependency footprint (#38825)

scripts/lint/check_dependencies.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+import sys
+import tomllib
+import importlib.metadata
+from pathlib import Path
+
+
+def main() -> int:
+  if sys.prefix == sys.base_prefix:
+    print("Dependency checks require a virtual environment. Run tools/op.sh setup first.")
+    return 1
+
+  project = tomllib.loads((Path(__file__).resolve().parents[2] / "pyproject.toml").read_text())["project"]
+  direct = len(project["dependencies"]) + sum(len(deps) for deps in project["optional-dependencies"].values())
+  # Count each installed package once, including transitive dependencies and all extras.
+  packages = {dist.metadata["Name"].lower().replace("_", "-") for dist in importlib.metadata.distributions()}
+  # Logical file sizes avoid filesystem block-size differences. Don't follow links to the interpreter or source tree.
+  size = sum(path.stat().st_size for path in Path(sys.prefix).rglob("*") if not path.is_symlink() and path.is_file())
+
+  """
+    This test prevents our depency footprint from growing.
+    These values are *not* intended to be increased, and we
+    expect to strictly drive these down over time.
+  """
+  failed = False
+  for name, value, limit in (
+    ("Direct dependencies (all extras)", direct, 37),
+    ("Total dependencies", len(packages), 65),
+    ("Venv size (MiB)", size / 1024**2, 550),
+  ):
+    print(f"{name}: {value:g} (limit: {limit})")
+    failed |= value > limit
+  return int(failed)
+
+
+if __name__ == "__main__":
+  raise SystemExit(main())

scripts/lint/lint.sh

@@ -46,6 +46,7 @@ function run_tests() {
   PYTHON_FILES=$2
 
   run "ruff" ruff check openpilot --quiet
+  run "check_dependencies" python3 $DIR/check_dependencies.py
   run "check_indentation" $DIR/check_indentation.py $PYTHON_FILES
   run "check_added_large_files" $DIR/check_added_large_files.py --maxkb=120 $ALL_FILES
   run "check_shebang_scripts_are_executable" $DIR/check_shebang_scripts_are_executable.py $ALL_FILES
@@ -67,6 +68,7 @@ function help() {
   echo ""
   echo -e "${BOLD}${UNDERLINE}Tests:${NC}"
   echo -e "  ${BOLD}ruff${NC}"
+  echo -e "  ${BOLD}check_dependencies${NC}"
   echo -e "  ${BOLD}check_indentation${NC}"
   echo -e "  ${BOLD}ty${NC}"
   echo -e "  ${BOLD}codespell${NC}"