diff --git a/lib/REST/TinyTinyRSS/API.php b/lib/REST/TinyTinyRSS/API.php
index 11b983d..3732623 100644
--- a/lib/REST/TinyTinyRSS/API.php
+++ b/lib/REST/TinyTinyRSS/API.php
@@ -947,7 +947,7 @@ class API extends \JKingWeb\Arsse\REST\AbstractHandler {
             throw new Exception("INCORRECT_USAGE");
         }
         try {
-            Arsse::$db->feedUpdate(Arsse::$db->subscriptionPropertiesGet(Arsse::$user->id, $data['feed_id'])['feed']);
+            Arsse::$db->feedUpdate((int) Arsse::$db->subscriptionPropertiesGet(Arsse::$user->id, $data['feed_id'])['feed']);
         } catch (ExceptionInput $e) {
             throw new Exception("FEED_NOT_FOUND");
         }
@@ -973,7 +973,7 @@ class API extends \JKingWeb\Arsse\REST\AbstractHandler {
         // this function doesn't complain about invalid article IDs
         $article = V::id($data['article_id']) ? $data['article_id'] : 0;
         try {
-            $list = $article ? Arsse::$db->articleLabelsGet(Arsse::$user->id, $article) : [];
+            $list = $article ? Arsse::$db->articleLabelsGet(Arsse::$user->id, (int) $article) : [];
         } catch (ExceptionInput $e) {
             $list = [];
         }
diff --git a/lib/User/Driver.php b/lib/User/Driver.php
index 8766879..fcf2010 100644
--- a/lib/User/Driver.php
+++ b/lib/User/Driver.php
@@ -7,8 +7,6 @@ declare(strict_types=1);
 namespace JKingWeb\Arsse\User;
 
 interface Driver {
-    public function __construct();
-
     /** Returns a human-friendly name for the driver (for display in installer, for example) */
     public static function driverName(): string;
 
diff --git a/tests/lib/AbstractTest.php b/tests/lib/AbstractTest.php
index 5d9eb5e..3ed6fc4 100644
--- a/tests/lib/AbstractTest.php
+++ b/tests/lib/AbstractTest.php
@@ -226,7 +226,7 @@ abstract class AbstractTest extends \PHPUnit\Framework\TestCase {
         }
         foreach ($value as $k => $v) {
             if (is_array($v)) {
-                $value[$k] = $this->v($v);
+                $value[$k] = $this->stringify($v);
             } elseif (is_int($v) || is_float($v)) {
                 $value[$k] = (string) $v;
             }
@@ -324,6 +324,10 @@ abstract class AbstractTest extends \PHPUnit\Framework\TestCase {
     }
 
     public function assertResult(array $expected, Result $data): void {
+        // stringify our expectations if necessary
+        if (static::$stringOutput ?? false) {
+            $expected = $this->stringify($expected);
+        }
         $data = $data->getAll();
         $this->assertCount(sizeof($expected), $data, "Number of result rows (".sizeof($data).") differs from number of expected rows (".sizeof($expected).")");
         if (sizeof($expected)) {
@@ -337,12 +341,19 @@ abstract class AbstractTest extends \PHPUnit\Framework\TestCase {
             }
             // filter the result set to contain just the desired keys (we don't care if the result has extra keys)
             $rows = [];
+            $keys = array_keys($keys);
             foreach ($data as $row) {
-                $rows[] = array_intersect_key($row, $keys);
+                $r = [];
+                foreach ($keys as $k) {
+                    if (array_key_exists($k, $row)) {
+                        $r[$k] = $row[$k];
+                    }
+                }
+                $rows[] = $r;
             }
             // compare the result set to the expectations
             foreach ($rows as $row) {
-                $this->assertEquals($row, $expected, "Result set contains unexpected record.");
+                $this->assertContains($row, $expected, "Result set contains unexpected record.\n".var_export($expected, true));
                 $found = array_search($row, $expected);
                 unset($expected[$found]);
             }