Fix countability bug.

module/VuFindSearch/src/VuFindSearch/ParamBag.php

@@ -41,7 +41,7 @@ namespace VuFindSearch;
  * @license  http://opensource.org/licenses/gpl-2.0.php GNU General Public License
  * @link     https://vufind.org
  */
-class ParamBag
+class ParamBag implements \Countable
 {
     /**
      * Parameters
@@ -238,4 +238,14 @@ class ParamBag
         }
         return $request;
     }
+
+    /**
+     * Get a count of parameters set in the bag.
+     *
+     * @return int
+     */
+    public function count()
+    {
+        return count($this->params);
+    }
 }

module/VuFindSearch/tests/unit-tests/src/VuFindTest/ParamBagTest.php

@@ -97,4 +97,19 @@ class ParamBagTest extends TestCase
         $bag3->mergeWithAll([$bag1, $bag2]);
         $this->assertEquals(['a' => [1], 'b' => [2], 'c' => [3]], $bag3->getArrayCopy());
     }
+
+    /**
+     * Test countability.
+     *
+     * @return void
+     */
+    public function testCountability()
+    {
+        $bag = new ParamBag();
+        $this->assertEquals(0, count($bag));
+        $bag->set('foo', 'bar');
+        $this->assertEquals(1, count($bag));
+        $bag->set('xyzzy', 'baz');
+        $this->assertEquals(2, count($bag));
+    }
 }