diff --git b/core/modules/update/tests/Drupal/update/Tests/UpdateCoreTest.php a/core/modules/update/tests/Drupal/update/Tests/UpdateCoreUnitTest.php
similarity index 55%
rename from core/modules/update/tests/Drupal/update/Tests/UpdateCoreTest.php
rename to core/modules/update/tests/Drupal/update/Tests/UpdateCoreUnitTest.php
index 445906a..08badcb 100644
--- b/core/modules/update/tests/Drupal/update/Tests/UpdateCoreTest.php
+++ a/core/modules/update/tests/Drupal/update/Tests/UpdateCoreUnitTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains \Drupal\update\Tests\UpdateCoreTest.
+ * Contains \Drupal\update\Tests\UpdateCoreUnitTest.
  */
 
 namespace Drupal\update\Tests;
@@ -13,56 +13,82 @@
 /**
  * Tests update functionality unrelated to the database.
  */
-class UpdateCoreTest extends UnitTestCase {
+class UpdateCoreUnitTest extends UnitTestCase {
+
+  /**
+   * Mimic this constant from bootstrap.inc.
+   */
+  const DRUPAL_CORE_COMPATIBILITY = '8.x';
+
+  /**
+   * The update fetcher to use.
+   *
+   * @var \Drupal\update\UpdateFetcher
+   */
+  protected $updateFetcher;
 
   public static function getInfo() {
     return array(
-      'name' => 'Unit tests',
+      'name' => 'Core update tests',
       'description' => 'Test update functionality unrelated to the database.',
       'group' => 'Update',
     );
   }
 
+  protected function setUp() {
+    $config_factory = $this->getConfigFactoryStub(array('update.settings' => array('fetch_url' => 'http://www.example.com')));
+    $this->updateFetcher = new UpdateFetcher($config_factory);
+  }
+
   /**
    * Tests that buildFetchUrl() builds the URL correctly.
+   *
+   * @dataProvider testUpdateBuildFetchUrlProvider
    */
-  public function testUpdateBuildFetchUrl() {
+  public function testUpdateBuildFetchUrl(array $project, $site_key, $expected) {
+    $url = $this->updateFetcher->buildFetchUrl($project, $site_key);
+    $this->assertEquals($url, $expected);
+  }
+
+  public function testUpdateBuildFetchUrlProvider() {
+    $data = array();
+
     // First test that we didn't break the trivial case.
-    $config_factory = $this->getConfigFactoryStub(array('update.settings' => array('fetch_url' => 'http://www.example.com')));
-    $update_fetcher = new UpdateFetcher($config_factory);
     $project['name'] = 'update_test';
     $project['project_type'] = '';
     $project['info']['version'] = '';
     $project['info']['project status url'] = 'http://www.example.com';
     $project['includes'] = array('module1' => 'Module 1', 'module2' => 'Module 2');
     $site_key = '';
-    $expected = 'http://www.example.com/' . $project['name'] . '/' . DRUPAL_CORE_COMPATIBILITY;
-    $url = $update_fetcher->buildFetchUrl($project, $site_key);
-    $this->assertEquals($url, $expected, "'$url' when no site_key provided should be '$expected'.");
+    $expected = 'http://www.example.com/' . $project['name'] . '/' . static::DRUPAL_CORE_COMPATIBILITY;
+
+    $data[] = array($project, $site_key, $expected);
 
-    //For disabled projects it shouldn't add the site key either.
+    // For disabled projects it shouldn't add the site key either.
     $site_key = 'site_key';
     $project['project_type'] = 'disabled';
-    $expected = 'http://www.example.com/' . $project['name'] . '/' . DRUPAL_CORE_COMPATIBILITY;
-    $url = $update_fetcher->buildFetchUrl($project, $site_key);
-    $this->assertEquals($url, $expected, "'$url' should be '$expected' for disabled projects.");
+    $expected = 'http://www.example.com/' . $project['name'] . '/' . static::DRUPAL_CORE_COMPATIBILITY;
 
-    //for enabled projects, adding the site key
+    $data[] = array($project, $site_key, $expected);
+
+    // For enabled projects, adding the site key
     $project['project_type'] = '';
-    $expected = 'http://www.example.com/' . $project['name'] . '/' . DRUPAL_CORE_COMPATIBILITY;
+    $expected = 'http://www.example.com/' . $project['name'] . '/' . static::DRUPAL_CORE_COMPATIBILITY;
     $expected .= '?site_key=site_key';
     $expected .= '&list=' . rawurlencode('module1,module2');
-    $url = $update_fetcher->buildFetchUrl($project, $site_key);
-    $this->assertEquals($url, $expected, "When site_key provided, '$url' should be '$expected'.");
+
+    $data[] = array($project, $site_key, $expected);
 
     // http://drupal.org/node/1481156 test incorrect logic when URL contains
     // a question mark.
     $project['info']['project status url'] = 'http://www.example.com/?project=';
-    $expected = 'http://www.example.com/?project=/' . $project['name'] . '/' . DRUPAL_CORE_COMPATIBILITY;
+    $expected = 'http://www.example.com/?project=/' . $project['name'] . '/' . static::DRUPAL_CORE_COMPATIBILITY;
     $expected .= '&site_key=site_key';
     $expected .= '&list=' . rawurlencode('module1,module2');
-    $url = $update_fetcher->buildFetchUrl($project, $site_key);
-    $this->assertEquals($url, $expected, "When ? is present, '$url' should be '$expected'.");
+
+    $data[] = array($project, $site_key, $expected);
+
+    return $data;
   }
 
 }