feat: MediaConchValidato,validate can run without a policy file

Author: henryborchers

src/uiucprescon/tripwire/metadata.py

@@ -7,6 +7,7 @@
 
 import abc
 import itertools
+import warnings
 from collections import defaultdict
 import json
 from dataclasses import dataclass, field
@@ -231,13 +232,14 @@ def _iter_failing_rules(
                         yield self.issue_formatter(rule)
 
     def validate(self, glob: str) -> ValidationResult:
-        if not self.policy_file:
-            raise ValueError("Policy file must be set before validation.")
 
         mc = self.mediaconch or self._get_media_conch()
-        if not self.validate_policy_file(self.policy_file):
-            raise ValueError("Policy file must be valid policy file.")
-        mc.add_policy(str(self.policy_file))
+        if not self.policy_file:
+            warnings.warn(UserWarning("No policy was set before validation"))
+        else:
+            if not self.validate_policy_file(self.policy_file):
+                raise ValueError("Policy file must be valid policy file.")
+            mc.add_policy(str(self.policy_file))
         final_results = MediaConchValidator._Results()
 
         try:
@@ -280,7 +282,7 @@ def get_mediaconch_results(
             assert item["ref"] == str(filepath), (
                 f"Expected {item['ref']} to be {filepath}"
             )
-            failing_rules = set(self._iter_failing_rules(item["policies"]))
+            failing_rules = set(self._iter_failing_rules(item.get("policies", [])))
             if failing_rules:
                 file_is_valid = False
             results.files_with_issues.add(

tests/test_metadata.py

@@ -251,12 +251,11 @@ def test_validate_loging_valid(
         assert "Validating dummy.mov" in str(caplog.records[0])
         assert caplog.records[1].levelname == expected_levelname
 
-    def test_validate_raises_without_policy_file(self):
+    def test_validate_without_policy_file_produces_warning(self):
         validator = metadata_module.MediaConchValidator()
         validator.iglob = lambda *_, **__: ["dummy.mov"]
-        with pytest.raises(
-            ValueError, match="Policy file must be set before validation."
-        ):
+        validator.get_mediaconch_results = Mock(name="get_mediaconch_results", return_value=validator._Results())
+        with pytest.warns(UserWarning):
             validator.validate("*.mov")
 
     def test_validate_raises_with_invalid_policy_file(self):