TST: Add tests for function used by entry-point.

Author: DWesl

src/check_python_h_first/__main__.py

@@ -19,18 +19,18 @@
 )
 
 
-def main():
+def main(argv: list[str] = None):
     """Run the checker on the files passed on the command line."""
-    args = PARSER.parse_args()
+    args = PARSER.parse_args(argv)
 
     files = args.files
     if len(files) == 1 and os.path.isdir(files[0]):
         files = find_c_cpp_files(files[0])
 
     # See which of the headers include Python.h and add them to the list
     n_out_of_order = process_files(files)
-    sys.exit(n_out_of_order)
+    return n_out_of_order
 
 
 if __name__ == "__main__":
-    main()
+    sys.exit(main())

tests/test_main.py

@@ -0,0 +1,21 @@
+"""Test the function used by the installed script."""
+
+import os.path
+
+import pytest
+
+from check_python_h_first.__main__ import main
+
+THIS_DIR = os.path.dirname(__file__)
+
+
+@pytest.mark.parametrize("to_pass", [None, []])
+def test_call_empty(to_pass):
+    """Test that calling without arguments fails."""
+    with pytest.raises(SystemExit):
+        assert main(to_pass) != 0
+
+
+def test_call_single():
+    """Test that calling with a single directory finds files."""
+    assert main([THIS_DIR]) > 0

tests/test_wrapper.py

@@ -42,7 +42,8 @@ def test_process_files():
     """
     result = process_files(HEADER_LIST + SOURCE_LIST)
     assert result == sum(
-        os.path.basename(name).startswith("system") or os.path.basename(name).startswith("bad")
+        os.path.basename(name).startswith("system")
+        or os.path.basename(name).startswith("bad")
         for name in HEADER_LIST + SOURCE_LIST
     )