Change find flavors method into utility function

fimfarchive/stampers.py

@@ -22,12 +22,13 @@ Stampers for Fimfarchive.
 #
 
 
-from typing import Any, Dict, Optional, Set, Type, TypeVar
+from typing import Any, Dict, Set
 
 import arrow
 
-from fimfarchive.flavors import Flavor, UpdateStatus
+from fimfarchive.flavors import UpdateStatus
 from fimfarchive.stories import Story
+from fimfarchive.utils import find_flavor
 
 
 __all__ = (
@@ -36,9 +37,6 @@ __all__ = (
 )
 
 
-F = TypeVar('F', bound=Flavor)
-
-
 class Stamper:
     """
     Adds archive-related information to stories.
@@ -90,23 +88,6 @@ class UpdateStamper(Stamper):
         },
     }
 
-    def find_flavor(self, story: Story, flavor: Type[F]) -> Optional[F]:
-        """
-        Searches for a flavor of a specific type.
-
-        Args:
-            story: The story to search in.
-            flavor: The flavor type to find.
-
-        Returns:
-            A flavor of the desired type, or None.
-        """
-        for current in story.flavors:
-            if isinstance(current, flavor):
-                return current
-
-        return None
-
     def __call__(self, story: Story) -> None:
         """
         Applies modification dates to a story.
@@ -115,7 +96,7 @@ class UpdateStamper(Stamper):
             story: The story to stamp.
         """
         timestamp = arrow.utcnow().isoformat()
-        flavor = self.find_flavor(story, UpdateStatus)
+        flavor = find_flavor(story, UpdateStatus)
         archive = self.get_archive(story)
 
         archive['date_checked'] = timestamp

fimfarchive/utils.py

@@ -25,15 +25,22 @@ Various utilities.
 import json
 import os
 import shutil
-from typing import Dict, Any
+from typing import Any, Dict, Optional, Type, TypeVar
+
+from fimfarchive.flavors import Flavor
+from fimfarchive.stories import Story
 
 
 __all__ = (
     'Empty',
     'PersistedDict',
+    'find_flavor',
 )
 
 
+F = TypeVar('F', bound=Flavor)
+
+
 class EmptyMeta(type):
     """
     Meta-class for Empty.
@@ -101,3 +108,21 @@ class PersistedDict(Dict[str, Any]):
 
         if os.path.exists(self.temp):
             os.remove(self.temp)
+
+
+def find_flavor(story: Story, flavor: Type[F]) -> Optional[F]:
+    """
+    Searches for a flavor of a specific type.
+
+    Args:
+        story: The story to search in.
+        flavor: The flavor type to find.
+
+    Returns:
+        A flavor of the desired type, or None.
+    """
+    for current in story.flavors:
+        if isinstance(current, flavor):
+            return current
+
+    return None

tests/test_stampers.py

@@ -63,8 +63,8 @@ class TestStamper:
         meta['archive'] = original
         archive = stamper.get_archive(story)
 
-        assert archive is original
         assert meta['archive'] is original
+        assert archive is original
 
 
 class TestUpdateStamper:

tests/test_utils.py

@@ -27,7 +27,8 @@ import os
 
 import pytest
 
-from fimfarchive.utils import Empty, PersistedDict
+from fimfarchive.flavors import DataFormat, MetaFormat, MetaPurity
+from fimfarchive.utils import find_flavor, Empty, PersistedDict
 
 
 class TestEmpty:
@@ -189,3 +190,33 @@ class TestPersistedDict:
         data = PersistedDict(tmpfile, default=extra)
 
         assert dict(data) == sample
+
+
+class TestFindFlavor:
+    """
+    find_flavor tests.
+    """
+
+    @pytest.fixture
+    def story(self, story):
+        """
+        Returns a meta-flavored story.
+        """
+        return story.merge(flavors=[
+            MetaFormat.BETA,
+            MetaPurity.CLEAN,
+        ])
+
+    def test_present_flavor(self, story):
+        """
+        Tests flavor is returned when present.
+        """
+        found = find_flavor(story, MetaFormat)
+        assert found == MetaFormat.BETA
+
+    def test_missing_flavor(self, story):
+        """
+        Tests None is returned when flavor is missing.
+        """
+        found = find_flavor(story, DataFormat)
+        assert found is None