diff -u b/core/modules/simpletest/simpletest.module b/core/modules/simpletest/simpletest.module
--- b/core/modules/simpletest/simpletest.module
+++ b/core/modules/simpletest/simpletest.module
@@ -820,20 +820,10 @@
   if (!$contents) {
     return;
   }
-  $xml = new SimpleXMLElement($contents);
   $records = array();
-  foreach ($xml->testsuite as $testsuite) {
-    foreach ($testsuite as $suite) {
-      // The file element won't be on testcase objects created with
-      // @dataProvider, so just use the one from the test suite at this level
-      // because it should be the same.
-      $file = (string) $suite->attributes()->file;
-
-      $testcases = simpletest_phpunit_find_testcases($suite);
-      foreach ($testcases as $testcase) {
-        $records[] = simpletest_phpunit_testcase_to_row($test_id, $testcase, $file);
-      }
-    }
+  $testcases = simpletest_phpunit_find_testcases(new SimpleXMLElement($contents));
+  foreach ($testcases as $testcase) {
+    $records[] = simpletest_phpunit_testcase_to_row($test_id, $testcase);
   }
   return $records;
 }
@@ -841,27 +831,38 @@
 /**
  * Finds all test cases recursively from a test suite list.
  *
- * @param \SimpleXMLElement[] $suite
- *   The list of test cases contained in the PHPUnit XML.
+ * @param \SimpleXMLElement $element
+ *   The PHPUnit xml to search for test cases.
+ * @param \SimpleXMLElement $suite
+ *   (Optional) The parent of the current element. Defaults to NULL.
  *
  * @return array
  *   A list of all test cases.
  */
-function simpletest_phpunit_find_testcases($suite) {
+function simpletest_phpunit_find_testcases(\SimpleXMLElement $element, \SimpleXMLElement $parent = NULL) {
   $testcases = array();
 
-  foreach ($suite as $testcase) {
-    // Beside from being 'testcases', it could be also a group of testcases.
-    // This happens if you use a data provider in the PHPUnit tests.
-    if ($testcase->getName() === 'testcase') {
-      $testcases[] = $testcase;
+  if (!isset($parent)) {
+    $parent = $element;
+  }
+
+  if ($element->getName() === 'testcase' && (int) $parent->attributes()->tests > 0) {
+    // Add the class attribute if the testcase does not have one. This is the
+    // case for tests using a data provider. The name of the parent testsuite
+    // will be in the format class::method.
+    if (!$element->attributes()->class) {
+      $name = explode('::', $parent->attributes()->name, 2);
+      $element->addAttribute('class', $name[0]);
     }
-    elseif (isset($testcase->testcase) && ((int) $testcase->attributes()->tests) > 0) {
-      foreach ($testcase->testcase as $childtestcase) {
-        // Add the class attribute since the child test case will not have it.
-        $childtestcase->addAttribute('class', $suite->attributes()->name);
-        $testcases[] = $childtestcase;
+    $testcases[] = $element;
+  }
+  else {
+    foreach ($element as $child) {
+      $file = (string) $parent->attributes()->file;
+      if ($file && !$child->attributes()->file) {
+        $child->addAttribute('file', $file);
       }
+      $testcases = array_merge($testcases, simpletest_phpunit_find_testcases($child, $element));
     }
   }
   return $testcases;
@@ -874,13 +875,11 @@
  *   The current test ID.
  * @param \SimpleXMLElement $testcase
  *   The PHPUnit test case represented as XML element.
- * @param string $file
- *   The path to test file, which was executed.
  *
  * @return array
  *   An array containing the {simpletest} result row.
  */
-function simpletest_phpunit_testcase_to_row($test_id, \SimpleXMLElement $testcase, $file) {
+function simpletest_phpunit_testcase_to_row($test_id, \SimpleXMLElement $testcase) {
   $message = '';
   $pass = TRUE;
   if ($testcase->failure) {
@@ -904,7 +903,7 @@
     'message_group' => 'Other',
     'function' => $attributes->class . '->' . $attributes->name . '()',
     'line' => $attributes->line ?: 0,
-    'file' => $file,
+    'file' => $attributes->file,
   );
   return $record;
 }