fix: report invalid HAR archives cleanly

python/extract_har.py

@@ -70,7 +70,12 @@ def extract_har(harzip, mimetypes, output, paths, pretty_json):
     output_dir = Path(output)
     output_dir.mkdir(parents=True, exist_ok=True)
 
-    with zipfile.ZipFile(harzip) as zf:
+    try:
+        archive = zipfile.ZipFile(harzip)
+    except zipfile.BadZipFile as exc:
+        raise click.ClickException(f"Invalid ZIP archive: {harzip}") from exc
+
+    with archive as zf:
         # Read the HAR JSON file
         try:
             har_content = json.loads(zf.read("har.har"))

python/test_extract_har.py

@@ -0,0 +1,33 @@
+import importlib.util
+import tempfile
+import unittest
+from pathlib import Path
+
+from click.testing import CliRunner
+
+
+SCRIPT = Path(__file__).with_name("extract_har.py")
+SPEC = importlib.util.spec_from_file_location("extract_har", SCRIPT)
+MODULE = importlib.util.module_from_spec(SPEC)
+SPEC.loader.exec_module(MODULE)
+
+
+class ExtractHarBadZipTests(unittest.TestCase):
+    def test_non_zip_input_returns_a_click_error_without_traceback(self):
+        runner = CliRunner()
+        with tempfile.TemporaryDirectory() as directory:
+            input_path = Path(directory) / "invalid.txt"
+            input_path.write_text("not a zip file", encoding="utf-8")
+
+            result = runner.invoke(
+                MODULE.extract_har,
+                [str(input_path), "text/plain", "--output", str(Path(directory) / "out")],
+            )
+
+        self.assertEqual(result.exit_code, 1)
+        self.assertIn("Invalid ZIP archive", result.output)
+        self.assertNotIn("Traceback", result.output)
+
+
+if __name__ == "__main__":
+    unittest.main()