1 files changed, 20 insertions, 12 deletions
diff --git a/lint/run_strict_deps.py b/lint/run_strict_deps.py
index c963f3cd..7f2ddcf4 100755
--- a/lint/run_strict_deps.py
+++ b/lint/run_strict_deps.py
@@ -16,25 +16,33 @@
 import json
 import os
 
-import json
-import os
 import sys
 
+from typing import List
 
-def dump_meta(src, cmd):
+
+def dump_meta(src: str, cmd: List[str]) -> None:
+    """Dump linter action metadata for further analysis."""
     OUT = os.environ.get("OUT")
     if OUT:
         with open(os.path.join(OUT, "config.json"), "w") as f:
             json.dump({"src": src, "cmd": cmd}, f)
 
 
-def run_lint(src, cmd):
+def run_lint(src: str, cmd: List[str]) -> int:
+    """Run the lint command for the specified source file."""
     dump_meta(src, cmd)
 
-    with open(os.environ.get("META")) as f:
+    META = os.environ.get("META")
+    if META is None:
+        print("Failed to get META", file=sys.stderr)
+        return 1
+
+    direct: List[str] = []
+    with open(META) as f:
         direct = json.load(f)["direct deps artifact names"]
 
-    include_dirs = []
+    include_dirs: List[str] = []
     for i in range(len(cmd)):
         if cmd[i] in ["-I", "-isystem"]:
             include_dirs += [cmd[i + 1]]
@@ -42,16 +50,16 @@ def run_lint(src, cmd):
     with open(src) as f:
         lines = f.read().splitlines()
 
-    failed = False
+    failed: bool = False
 
-    def include_covered(include_path):
+    def include_covered(include_path: str) -> bool:
         for d in direct:
             rel_path = os.path.relpath(include_path, d)
             if not rel_path.startswith('../'):
                 return True
         return False
 
-    def handle_resolved_include(i, to_include, resolved):
+    def handle_resolved_include(i: int, resolved: str) -> None:
         nonlocal failed
         if not include_covered(resolved):
             failed = True
@@ -60,11 +68,11 @@ def run_lint(src, cmd):
                 "    ---> including %r which is only provided by an indirect dependency"
                 % (resolved, ))
 
-    def handle_include(i, to_include):
+    def handle_include(i: int, to_include: str) -> None:
         for d in include_dirs:
             candidate = os.path.join(d, to_include)
             if os.path.exists(candidate):
-                handle_resolved_include(i, to_include, candidate)
+                handle_resolved_include(i, candidate)
 
     for i in range(len(lines)):
         to_include = None
@@ -72,7 +80,7 @@ def run_lint(src, cmd):
             to_include = lines[i].split('"')[1]
         if lines[i].startswith('#include <'):
             to_include = lines[i].split('<', 1)[1].split('>')[0]
-        if to_include:
+        if to_include:  # if non-empty string
             handle_include(i, to_include)
 
     return 1 if failed else 0