#4 added failing test for cache pruning

cellxgene_gateway/prune_process_cache.py

@@ -21,17 +21,20 @@ class PruneProcessCache:
     def __call__(self):
         while True:
             time.sleep(60)
+            self.prune()
 
-            timestamp = current_time_stamp()
+    def prune(self):
+        timestamp = current_time_stamp()
 
-            processes_to_delete = []
-            for p in self.cache.entry_list:
-                if timestamp - p.timestamp > (3600 if ttl is None else ttl):
-                    processes_to_delete.append(p)
-                    processes_to_delete
+        processes_to_delete = []
+        for p in self.cache.entry_list:
+            if timestamp - p.timestamp > (3600 if ttl is None else ttl):
+                processes_to_delete.append(p)
+                processes_to_delete
+
+        for process in processes_to_delete:
+            try:
+                cache.prune(process)
+            except Exception:
+                logging.getLogger("werkzeug").exception("failed to prune process")
 
-            for process in processes_to_delete:
-                try:
-                    cache.prune(process)
-                except Exception:
-                    logging.getLogger("werkzeug").exception("failed to prune process")

tests/test_prune_process_cache.py

@@ -0,0 +1,26 @@
+import unittest
+from unittest.mock import MagicMock, patch
+from cellxgene_gateway.cache_entry import CacheEntry
+from cellxgene_gateway.backend_cache import BackendCache
+
+class TestPruneProcessCache(unittest.TestCase):
+    @patch('cellxgene_gateway.util.current_time_stamp', new=lambda:0)
+    @patch('cellxgene_gateway.env.ttl', new='10')
+    @patch('cellxgene_gateway.cache_entry.CacheEntry')
+    @patch('cellxgene_gateway.cache_entry.CacheEntry')
+    def test_GIVEN_one_old_one_new_THEN_prune_old(self, old, new):
+        from cellxgene_gateway.prune_process_cache import PruneProcessCache
+
+        cache = BackendCache()
+        old.timestamp = -100
+        cache.entry_list.append(old)
+        new.timestamp = -5
+        cache.entry_list.append(new)
+        self.assertEqual(len(cache.entry_list), 2)
+        ppc = PruneProcessCache(cache)
+        ppc.prune()
+        self.assertEqual(len(cache.entry_list), 1)
+        self.assertEqual(cache.entry_list[0], new)
+
+if __name__ == '__main__':
+    unittest.main()