feat(results): improve human readability of semantic validation results

nac_validate/validator.py

@@ -176,9 +176,9 @@ def validate_semantics(self, input_paths: list[Path]) -> None:
 
         if len(results) > 0:
             for id, paths in results.items():
-                msg = (
-                    f"Semantic error, rule {id}: {self.rules[id].description} ({paths})"
-                )
+                header = f"Semantic error, rule {id}: {self.rules[id].description}:"
+                items = "\n".join(f"    - {path}" for path in paths)
+                msg = f"{header}\n{items}"
                 logger.error(msg)
                 semantic_errors.append(msg)
 

tests/integration/test_integration.py

@@ -225,3 +225,22 @@ def test_merge(tmpdir: Path) -> None:
     )
     assert result.exit_code == 0
     assert filecmp.cmp(output_path, result_path, shallow=False)
+
+
+def test_semantic_error_output_format() -> None:
+    """Test that semantic errors are formatted as a human-readable bulleted list."""
+    runner = CliRunner()
+    input_path = "tests/integration/fixtures/data_semantic_error/"
+    rules_path = "tests/integration/fixtures/rules/"
+    result = runner.invoke(
+        nac_validate.cli.main.app,
+        ["-r", rules_path, "-v", "ERROR", input_path],
+    )
+    assert result.exit_code == 1
+    # Verify bulleted list format with 4-space indent
+    assert "    - " in result.output
+    # Verify header ends with colon (not parentheses with list)
+    assert "Semantic error, rule 101:" in result.output
+    # Verify no Python list representation in output
+    assert '["' not in result.output
+    assert "']" not in result.output