diff --git a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
new file mode 100644
index 0000000..f341ec1
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
@@ -0,0 +1,128 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\Core\Config\Schema\SchemaCheckTrait.
+ */
+
+namespace Drupal\Core\Config\Schema;
+
+use Drupal\Core\Config\TypedConfigManagerInterface;
+use Drupal\Core\TypedData\PrimitiveInterface;
+use Drupal\Core\TypedData\Type\BooleanInterface;
+use Drupal\Core\TypedData\Type\StringInterface;
+use Drupal\Core\TypedData\Type\FloatInterface;
+use Drupal\Core\TypedData\Type\IntegerInterface;
+
+/**
+ * Provides a class for checking configuration schema.
+ */
+trait SchemaCheckTrait {
+
+  /**
+   * The config schema wrapper object for the configuration object under test.
+   *
+   * @var \Drupal\Core\Config\Schema\Element
+   */
+  protected $schema;
+
+  /**
+   * The configuration object name under test.
+   *
+   * @var string
+   */
+  protected $configName;
+
+  /**
+   * Checks the TypedConfigManager has a valid schema for the configuration.
+   *
+   * @param \Drupal\Core\Config\TypedConfigManagerInterface $typed_config
+   *   The TypedConfigManager.
+   * @param string $config_name
+   *   The configuration name.
+   * @param array $config_data
+   *   The configuration data.
+   *
+   * @return array|FALSE|TRUE
+   *   False if no schema found. List of errors if any found. TRUE if fully
+   *   valid.
+   */
+  public function checkConfigSchema(TypedConfigManagerInterface $typed_config, $config_name, $config_data) {
+    $this->configName = $config_name;
+    if (!$typed_config->hasConfigSchema($config_name)) {
+      return FALSE;
+    }
+    $definition = $typed_config->getDefinition($config_name);
+    $this->schema = $typed_config->create($definition, $config_data);
+    foreach ($config_data as $key => $value) {
+      $errors = $this->checkValue($key, $value);
+    }
+    if (empty($errors)) {
+      return TRUE;
+    }
+    return $errors;
+  }
+
+  /**
+   * Helper method to check data type.
+   *
+   * @param string $key
+   *   A string of configuration key.
+   * @param mixed $value
+   *   Value of given key.
+   *
+   * @return array
+   *   List of errors found while checking with the corresponding schema.
+   */
+  protected function checkValue($key, $value) {
+    $error_key = $this->configName . ':' . $key;
+    $element = FALSE;
+    try {
+      $element = $this->schema->get($key);
+    }
+    catch (SchemaIncompleteException $e) {
+      if (is_scalar($value) || $value === NULL) {
+        return array($error_key => 'Missing schema.');
+      }
+    }
+    // Do not check value if it is defined to be ignored.
+    if ($element && $element instanceof Ignore) {
+      return array();
+    }
+
+    if ($element && is_scalar($value) || $value === NULL) {
+      $success = FALSE;
+      $type = gettype($value);
+      if ($element instanceof PrimitiveInterface) {
+        $success =
+          ($type == 'integer' && $element instanceof IntegerInterface) ||
+          ($type == 'double' && $element instanceof FloatInterface) ||
+          ($type == 'boolean' && $element instanceof BooleanInterface) ||
+          ($type == 'string' && $element instanceof StringInterface) ||
+          // Null values are allowed for all types.
+          ($value === NULL);
+      }
+      $class = get_class($element);
+      if (!$success) {
+        return array($error_key => "Variable type is $type but applied schema class is $class.");
+      }
+    }
+    else {
+      $errors = array();
+      if (!$element instanceof ArrayElement) {
+        $errors[$error_key] = 'Non-scalar value but not defined as an array (such as mapping or sequence)';
+      }
+
+      // Go on processing so we can get errors on all levels. Any non-scalar
+      // value must be an array so cast to an array.
+      if (!is_array($value)) {
+        $value = (array) $value;
+      }
+      // Recurse into any nested keys.
+      foreach ($value as $nested_value_key => $nested_value) {
+        $errors = array_merge($errors, $this->checkValue($key . '.' . $nested_value_key, $nested_value));
+      }
+      return $errors;
+    }
+  }
+}
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTestBase.php b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTestBase.php
index eac1a75..f1400d0 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTestBase.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTestBase.php
@@ -7,42 +7,16 @@
 
 namespace Drupal\config\Tests;
 
-use Drupal\Core\Config\Schema\ArrayElement;
 use Drupal\Core\Config\TypedConfigManagerInterface;
-use Drupal\Core\TypedData\Type\BooleanInterface;
-use Drupal\Core\TypedData\Type\StringInterface;
 use Drupal\Component\Utility\String;
-use Drupal\Core\Config\Schema\SchemaIncompleteException;
-use Drupal\Core\TypedData\PrimitiveInterface;
-use Drupal\Core\TypedData\Type\FloatInterface;
-use Drupal\Core\TypedData\Type\IntegerInterface;
+use Drupal\Core\Config\Schema\SchemaCheckTrait;
 use Drupal\simpletest\WebTestBase;
 
 /**
  * Provides a base class to help test configuration schema.
  */
 abstract class ConfigSchemaTestBase extends WebTestBase {
-
-  /**
-   * The config schema wrapper object for the configuration object under test.
-   *
-   * @var \Drupal\Core\Config\Schema\Element
-   */
-  protected $schema;
-
-  /**
-   * The configuration object name under test.
-   *
-   * @var string
-   */
-  protected $configName;
-
-  /**
-   * Global state for whether the config has a valid schema.
-   *
-   * @var boolean
-   */
-  protected $configPass;
+  use SchemaCheckTrait;
 
   /**
    * Asserts the TypedConfigManager has a valid schema for the configuration.
@@ -55,89 +29,18 @@
    *   The configuration data.
    */
   public function assertConfigSchema(TypedConfigManagerInterface $typed_config, $config_name, $config_data) {
-    $this->configName = $config_name;
-    if (!$typed_config->hasConfigSchema($config_name)) {
+    $errors = $this->checkConfigSchema($typed_config, $config_name, $config_data);
+    if ($errors === FALSE) {
       $this->fail(String::format('No schema for !config_name', array('!config_name' => $config_name)));
       return;
     }
-    $definition = $typed_config->getDefinition($config_name);
-    $this->schema = $typed_config->create($definition, $config_data);
-    $this->configPass = TRUE;
-    foreach ($config_data as $key => $value) {
-      $this->checkValue($key, $value);
-    }
-    if ($this->configPass) {
+    elseif ($errors === TRUE) {
       $this->pass(String::format('Schema found for !config_name and values comply with schema.', array('!config_name' => $config_name)));
     }
-  }
-
-  /**
-   * Helper method to check data type.
-   *
-   * @param string $key
-   *   A string of configuration key.
-   * @param mixed $value
-   *   Value of given key.
-   *
-   * @return mixed
-   *   Returns mixed value.
-   */
-  protected function checkValue($key, $value) {
-    $element = FALSE;
-    try {
-      $element = $this->schema->get($key);
-    }
-    catch (SchemaIncompleteException $e) {
-      if (is_scalar($value) || $value === NULL) {
-        $this->fail("{$this->configName}:$key has no schema.");
-      }
-    }
-    // Do not check value if it is defined to be ignored.
-    if ($element && $element instanceof Ignore) {
-      return $value;
-    }
-
-    if (is_scalar($value) || $value === NULL) {
-      $success = FALSE;
-      $type = gettype($value);
-      if ($element instanceof PrimitiveInterface) {
-        $success =
-          ($type == 'integer' && $element instanceof IntegerInterface) ||
-          ($type == 'double' && $element instanceof FloatInterface) ||
-          ($type == 'boolean' && $element instanceof BooleanInterface) ||
-          ($type == 'string' && $element instanceof StringInterface) ||
-          // Null values are allowed for all types.
-          ($value === NULL);
-      }
-      $class = get_class($element);
-      if (!$success) {
-        $this->fail("{$this->configName}:$key has the wrong schema. Variable type is $type and schema class is $class.");
-      }
-    }
     else {
-      if (!$element instanceof ArrayElement) {
-        $this->fail("Non-scalar {$this->configName}:$key is not defined as an array type (such as mapping or sequence).");
-      }
-
-      // Go on processing so we can get errors on all levels. Any non-scalar
-      // value must be an array so cast to an array.
-      if (!is_array($value)) {
-        $value = (array) $value;
-      }
-      // Recurse into any nested keys.
-      foreach ($value as $nested_value_key => $nested_value) {
-        $value[$nested_value_key] = $this->checkValue($key . '.' . $nested_value_key, $nested_value);
+      foreach ($errors as $key => $error) {
+        $this->fail($key . ': ' . $error);
       }
     }
-    return $value;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function fail($message = NULL, $group = 'Other') {
-    $this->configPass = FALSE;
-    return parent::fail($message, $group);
   }
-
 }