diff --git a/lib/Service.php b/lib/Service.php
index bd02fc9..ed234d6 100644
--- a/lib/Service.php
+++ b/lib/Service.php
@@ -12,18 +12,14 @@ class Service {
     const DRIVER_NAMES = [
         'serial'     => \JKingWeb\Arsse\Service\Serial\Driver::class,
         'subprocess' => \JKingWeb\Arsse\Service\Subprocess\Driver::class,
-        'curl'       => \JKingWeb\Arsse\Service\Curl\Driver::class,
     ];
 
     /** @var Service\Driver */
     protected $drv;
-    /** @var \DateInterval */
-    protected $interval;
 
     public function __construct() {
         $driver = Arsse::$conf->serviceDriver;
         $this->drv = new $driver();
-        $this->interval = Arsse::$conf->serviceFrequency;
     }
 
     public function watch(bool $loop = true): \DateTimeInterface {
@@ -34,12 +30,12 @@ class Service {
             $list = Arsse::$db->feedListStale();
             if ($list) {
                 $this->drv->queue(...$list);
+                unset($list);
                 $this->drv->exec();
                 $this->drv->clean();
-                unset($list);
             }
             static::cleanupPost();
-            $t->add($this->interval);
+            $t->add(Arsse::$conf->serviceFrequency);
             // @codeCoverageIgnoreStart
             if ($loop) {
                 do {
diff --git a/lib/Service/Driver.php b/lib/Service/Driver.php
index 0f63383..e2dcf92 100644
--- a/lib/Service/Driver.php
+++ b/lib/Service/Driver.php
@@ -11,5 +11,5 @@ interface Driver {
     public static function requirementsMet(): bool;
     public function queue(int ...$feeds): int;
     public function exec(): int;
-    public function clean(): bool;
+    public function clean(): int;
 }
diff --git a/lib/Service/Serial/Driver.php b/lib/Service/Serial/Driver.php
index df3580c..dc2c74f 100644
--- a/lib/Service/Serial/Driver.php
+++ b/lib/Service/Serial/Driver.php
@@ -36,8 +36,9 @@ class Driver implements \JKingWeb\Arsse\Service\Driver {
         return Arsse::$conf->serviceQueueWidth - sizeof($this->queue);
     }
 
-    public function clean(): bool {
+    public function clean(): int {
+        $out = sizeof($this->queue);
         $this->queue = [];
-        return true;
+        return $out;
     }
 }
diff --git a/lib/Service/Subprocess/Driver.php b/lib/Service/Subprocess/Driver.php
index 5e79ed0..0986f2c 100644
--- a/lib/Service/Subprocess/Driver.php
+++ b/lib/Service/Subprocess/Driver.php
@@ -33,7 +33,7 @@ class Driver implements \JKingWeb\Arsse\Service\Driver {
             $id = (int) array_shift($this->queue);
             $php = escapeshellarg(\PHP_BINARY);
             $arsse = escapeshellarg($_SERVER['argv'][0]);
-            array_push($pp, popen("$php $arsse feed refresh $id", "r"));
+            array_push($pp, $this->execCmd("$php $arsse feed refresh $id"));
         }
         while ($pp) {
             $p = array_pop($pp);
@@ -43,8 +43,14 @@ class Driver implements \JKingWeb\Arsse\Service\Driver {
         return Arsse::$conf->serviceQueueWidth - sizeof($this->queue);
     }
 
-    public function clean(): bool {
+    /** @codeCoverageIgnore */
+    protected function execCmd(string $cmd) {
+        return popen($cmd, "r");
+    }
+
+    public function clean(): int {
+        $out = sizeof($this->queue);
         $this->queue = [];
-        return true;
+        return $out;
     }
 }
diff --git a/tests/cases/Service/TestSerial.php b/tests/cases/Service/TestSerial.php
new file mode 100644
index 0000000..5a96078
--- /dev/null
+++ b/tests/cases/Service/TestSerial.php
@@ -0,0 +1,47 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\TestCase\Service;
+
+use JKingWeb\Arsse\Arsse;
+use JKingWeb\Arsse\Database;
+use JKingWeb\Arsse\Service\Driver as DriverInterface;
+use JKingWeb\Arsse\Service\Serial\Driver;
+
+/** @covers \JKingWeb\Arsse\Service\Serial\Driver */
+class TestSerial extends \JKingWeb\Arsse\Test\AbstractTest {
+    public function setUp() {
+        self::clearData();
+        self::setConf();
+        Arsse::$db = \Phake::mock(Database::class);
+    }
+
+    public function testConstruct() {
+        $this->assertTrue(Driver::requirementsMet());
+        $this->assertInstanceOf(DriverInterface::class, new Driver);
+    }
+
+    public function testFetchDriverName() {
+        $this->assertTrue(strlen(Driver::driverName()) > 0);
+    }
+
+    public function testEnqueueFeeds() {
+        $d = new Driver;
+        $this->assertSame(3, $d->queue(1, 2, 3));
+        $this->assertSame(5, $d->queue(4, 5));
+        $this->assertSame(5, $d->clean());
+        $this->assertSame(1, $d->queue(5));
+    }
+
+    public function testRefreshFeeds() {
+        $d = new Driver;
+        $d->queue(1, 4, 3);
+        $this->assertSame(Arsse::$conf->serviceQueueWidth, $d->exec());
+        \Phake::verify(Arsse::$db)->feedUpdate(1);
+        \Phake::verify(Arsse::$db)->feedUpdate(4);
+        \Phake::verify(Arsse::$db)->feedUpdate(3);
+    }
+}
diff --git a/tests/cases/Service/TestService.php b/tests/cases/Service/TestService.php
index a1db862..102a9ce 100644
--- a/tests/cases/Service/TestService.php
+++ b/tests/cases/Service/TestService.php
@@ -59,4 +59,25 @@ class TestService extends \JKingWeb\Arsse\Test\AbstractTest {
         \Phake::verify(Arsse::$db)->articleCleanup();
         \Phake::verify(Arsse::$db)->driverMaintenance();
     }
+
+    public function testRefreshFeeds() {
+        // set up mock database actions
+        \Phake::when(Arsse::$db)->metaSet->thenReturn(true);
+        \Phake::when(Arsse::$db)->feedCleanup->thenReturn(true);
+        \Phake::when(Arsse::$db)->sessionCleanup->thenReturn(true);
+        \Phake::when(Arsse::$db)->articleCleanup->thenReturn(0);
+        \Phake::when(Arsse::$db)->feedListStale->thenReturn([1,2,3]);
+        // perform the test
+        $d = \Phake::mock(\JKingWeb\Arsse\Service\Driver::class);
+        $s = new \JKingWeb\Arsse\Test\Service($d);
+        $this->assertInstanceOf(\DateTimeInterface::class, $s->watch(false));
+        // verify invocations
+        \Phake::verify($d)->queue(1, 2, 3);
+        \Phake::verify($d)->exec();
+        \Phake::verify($d)->clean();
+        \Phake::verify(Arsse::$db)->feedCleanup();
+        \Phake::verify(Arsse::$db)->sessionCleanup();
+        \Phake::verify(Arsse::$db)->articleCleanup();
+        \Phake::verify(Arsse::$db)->metaSet("service_last_checkin", $this->anything(), "datetime");
+    }
 }
diff --git a/tests/cases/Service/TestSubprocess.php b/tests/cases/Service/TestSubprocess.php
new file mode 100644
index 0000000..c02c4b2
--- /dev/null
+++ b/tests/cases/Service/TestSubprocess.php
@@ -0,0 +1,48 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\TestCase\Service;
+
+use JKingWeb\Arsse\Arsse;
+use JKingWeb\Arsse\Database;
+use JKingWeb\Arsse\Service\Driver as DriverInterface;
+use JKingWeb\Arsse\Service\Subprocess\Driver;
+
+/** @covers \JKingWeb\Arsse\Service\Subprocess\Driver */
+class TestSubprocess extends \JKingWeb\Arsse\Test\AbstractTest {
+    public function setUp() {
+        self::clearData();
+        self::setConf();
+    }
+
+    public function testConstruct() {
+        $this->assertTrue(Driver::requirementsMet());
+        $this->assertInstanceOf(DriverInterface::class, new Driver);
+    }
+
+    public function testFetchDriverName() {
+        $this->assertTrue(strlen(Driver::driverName()) > 0);
+    }
+
+    public function testEnqueueFeeds() {
+        $d = new Driver;
+        $this->assertSame(3, $d->queue(1, 2, 3));
+        $this->assertSame(5, $d->queue(4, 5));
+        $this->assertSame(5, $d->clean());
+        $this->assertSame(1, $d->queue(5));
+    }
+
+    public function testRefreshFeeds() {
+        $d = \Phake::partialMock(Driver::class);
+        \Phake::when($d)->execCmd->thenReturnCallback(function(string $cmd) {
+            // FIXME: Does this work in Windows?
+            return popen("echo ".escapeshellarg($cmd), "r");
+        });
+        $this->assertSame(3, $d->queue(1, 4, 3));
+        $this->assertSame(Arsse::$conf->serviceQueueWidth, $d->exec());
+        \Phake::verify($d, \Phake::times(3))->execCmd;
+    }
+}
diff --git a/tests/cases/TestArsse.php b/tests/cases/TestArsse.php
index 179f399..f28e7ee 100644
--- a/tests/cases/TestArsse.php
+++ b/tests/cases/TestArsse.php
@@ -37,6 +37,9 @@ class TestArsse extends \JKingWeb\Arsse\Test\AbstractTest {
     }
 
     public function testLoadNewData() {
+        if (!\JKingWeb\Arsse\Db\SQLite3\Driver::requirementsMet() && !\JKingWeb\Arsse\Db\SQLite3\PDODriver::requirementsMet()) {
+            $this->markTestSkipped("A functional SQLite interface is required for this test");
+        }
         $conf = (new Conf)->import(['dbSQLite3File' => ":memory:"]);
         Arsse::load($conf);
         $this->assertInstanceOf(Conf::class, Arsse::$conf);
diff --git a/tests/lib/Service.php b/tests/lib/Service.php
new file mode 100644
index 0000000..cfd11f4
--- /dev/null
+++ b/tests/lib/Service.php
@@ -0,0 +1,13 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\Test;
+
+class Service extends \JKingWeb\Arsse\Service {
+    public function __construct(\JKingWeb\Arsse\Service\Driver $drv) {
+        $this->drv = $drv;
+    }
+}
diff --git a/tests/phpunit.dist.xml b/tests/phpunit.dist.xml
index dd2ba50..997c6a7 100644
--- a/tests/phpunit.dist.xml
+++ b/tests/phpunit.dist.xml
@@ -128,6 +128,8 @@
     </testsuite>
     <testsuite name="Admin tools">
         <file>cases/Service/TestService.php</file>
+        <file>cases/Service/TestSerial.php</file>
+        <file>cases/Service/TestSubprocess.php</file>
         <file>cases/CLI/TestCLI.php</file>
         <file>cases/TestArsse.php</file>
     </testsuite>