diff -u b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
--- b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
+++ b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
@@ -191,6 +191,28 @@
       $this->pass('The "name" field was found.');
     }
 
+    $this->assertFieldById('edit-name',NULL);
+    $this->assertFieldById('edit-name', 'Test name');
+    $this->assertFieldById('edit-description');
+
+    // Test that the assertion fails correctly if no value is passed in.
+    try {
+      $this->assertFieldById('edit-name');
+      $this->fail('The "edit-name" field with no value was found.');
+    }
+    catch (ExpectationException $e) {
+      $this->pass('The "edit-name" field with no value was not found.');
+    }
+
+    // Test that the assertion fails correctly if NULL is passed in.
+    try {
+      $this->assertFieldById('name', NULL);
+      $this->fail('The "name" field was found.');
+    }
+    catch (ExpectationException $e) {
+      $this->pass('The "name" field was not found.');
+    }    
+
     $this->assertNoFieldByName('name');
     $this->assertNoFieldByName('name', 'not the value');
     $this->assertNoFieldByName('notexisting');