diff --git a/lib/Conf.php b/lib/Conf.php
index 15a8345..13635c8 100644
--- a/lib/Conf.php
+++ b/lib/Conf.php
@@ -264,6 +264,7 @@ class Conf {
                     $type |= Value::M_NULL;
                 }
             } else {
+                // catch-all for custom properties
                 $type = Value::T_MIXED; // @codeCoverageIgnore
             }
             $out[$p->name] = ['name' => $match[0], 'const' => $type];
@@ -286,6 +287,7 @@ class Conf {
                 }
                 switch (self::EXPECTED_TYPES[$key] ?? gettype($this->$key)) {
                     case "integer":
+                        // no properties are currently typed as integers
                         return Value::normalize($value, Value::T_INT | $mode); // @codeCoverageIgnore
                     case "double":
                         return Value::normalize($value, Value::T_FLOAT | $mode);
@@ -293,6 +295,7 @@ class Conf {
                     case "object":
                         return $value;
                     default:
+                        // this should never occur
                         throw new Conf\Exception("ambiguousDefault", ['param' => $key]); // @codeCoverageIgnore
                 }
             }
diff --git a/lib/REST/Fever/API.php b/lib/REST/Fever/API.php
index ac85aa8..16bd889 100644
--- a/lib/REST/Fever/API.php
+++ b/lib/REST/Fever/API.php
@@ -207,7 +207,7 @@ class API extends \JKingWeb\Arsse\REST\AbstractHandler {
                 // indexed arrays
                 $p->appendChild($this->makeXMLIndexed($v, $d->createElement($k), substr($k, 0, strlen($k) - 1)));
             } else {
-                // this case does not actually occur in a proper Fever response
+                // this case is never encountered with Fever's output
                 $p->appendChild($this->makeXMLAssoc($v, $d->createElement($k))); // @codeCoverageIgnore
             }
         }
diff --git a/lib/Service.php b/lib/Service.php
index aed35c7..bd02fc9 100644
--- a/lib/Service.php
+++ b/lib/Service.php
@@ -40,11 +40,13 @@ class Service {
             }
             static::cleanupPost();
             $t->add($this->interval);
+            // @codeCoverageIgnoreStart
             if ($loop) {
                 do {
                     @time_sleep_until($t->getTimestamp());
                 } while ($t->getTimestamp() > time());
             }
+            // @codeCoverageIgnoreEnd
         } while ($loop);
         return $t;
     }
diff --git a/tests/cases/Service/TestService.php b/tests/cases/Service/TestService.php
index 3f6ea6b..a1db862 100644
--- a/tests/cases/Service/TestService.php
+++ b/tests/cases/Service/TestService.php
@@ -39,4 +39,24 @@ class TestService extends \JKingWeb\Arsse\Test\AbstractTest {
         $this->assertTrue(Service::hasCheckedIn());
         $this->assertFalse(Service::hasCheckedIn());
     }
+
+    public function testPerformPreCleanup() {
+        $this->assertTrue(Service::cleanupPre());
+        \Phake::verify(Arsse::$db)->feedCleanup();
+        \Phake::verify(Arsse::$db)->sessionCleanup();
+    }
+
+    public function testPerformShortPostCleanup() {
+        \Phake::when(Arsse::$db)->articleCleanup()->thenReturn(0);
+        $this->assertTrue(Service::cleanupPost());
+        \Phake::verify(Arsse::$db)->articleCleanup();
+        \Phake::verify(Arsse::$db, \Phake::times(0))->driverMaintenance();
+    }
+
+    public function testPerformFullPostCleanup() {
+        \Phake::when(Arsse::$db)->articleCleanup()->thenReturn(1);
+        $this->assertTrue(Service::cleanupPost());
+        \Phake::verify(Arsse::$db)->articleCleanup();
+        \Phake::verify(Arsse::$db)->driverMaintenance();
+    }
 }