diff --git a/cake/tests/cases/libs/test_manager.test.php b/cake/tests/cases/libs/test_manager.test.php
index b4e5defa3a7..2fd4c86b355 100644
--- a/cake/tests/cases/libs/test_manager.test.php
+++ b/cake/tests/cases/libs/test_manager.test.php
@@ -50,7 +50,7 @@ class TestManagerTest extends CakeTestCase {
 	public function setUp() {
 		$this->_countFiles = 0;
 		$this->TestManager = new TestTestManager();
-		$this->testSuiteStub = $this->getMock('PHPUnit_Framework_TestSuite');
+		$this->testSuiteStub = $this->getMock('CakeTestSuite');
 
 		$this->testSuiteStub
 			->expects($this->any())
@@ -93,6 +93,7 @@ protected function _getAllTestFiles($directory = CORE_TEST_CASES, $type = 'test'
  * @return void
  */
 	public function testRunAllTests() {
+		$this->Reporter->params = array('show' => 'cases');
 		$files = $this->_getAllTestFiles();
 		$result = $this->TestManager->runAllTests($this->Reporter, true);
 
@@ -115,7 +116,7 @@ public function testRunUnexistentCase() {
  * @return void
  */
 	public function testRunTestCase() {
-		$file = str_replace(CORE_TEST_CASES, '', __FILE__);
+		$file = __FILE__;
 		$result = $this->TestManager->runTestCase($file, $this->Reporter, true);
 		$this->assertEquals(1, $this->_countFiles);
 		$this->assertType('PHPUnit_Framework_TestResult', $result);
@@ -133,7 +134,7 @@ public function testRunGroupTest() {
 			return;
 		}
 		list($groupFile,) = explode('.', array_pop($groups), 2);
-		$result = $this->TestManager->runGroupTest(basename($groupFile), $this->Reporter);
+		$result = $this->TestManager->runGroupTest($groupFile, $this->Reporter);
 		$this->assertGreaterThan(0, $this->_countFiles);
 		$this->assertType('PHPUnit_Framework_TestResult', $result);
 	}
diff --git a/cake/tests/lib/test_manager.php b/cake/tests/lib/test_manager.php
index 2f322cf43d2..65d3a5fbedf 100644
--- a/cake/tests/lib/test_manager.php
+++ b/cake/tests/lib/test_manager.php
@@ -87,7 +87,7 @@ class TestManager {
  *
  * @return void
  */
-	public function __construct($params) {
+	public function __construct($params = array()) {
 		require_once(CAKE_TESTS_LIB . 'cake_test_case.php');
 		if (isset($params['app'])) {
 			$this->appTest = true;
@@ -111,7 +111,7 @@ public function __construct($params) {
  * @return mixed
  */
 	public function runAllTests(&$reporter) {
-		$testCases = $this->_getTestFileList($this->_getTestsPath());
+		$testCases = $this->_getTestFileList($this->_getTestsPath($reporter->params));
 
 		if ($this->appTest) {
 			$test = $this->getTestSuite(__('All App Tests', true));
@@ -157,7 +157,7 @@ public function runTestCase($testCaseFile, PHPUnit_Framework_TestListener $repor
  * @return mixed Results of group test being run.
  */
 	public function runGroupTest($groupTestName, $reporter, $codeCoverage = false) {
-		$filePath = $this->_getTestsPath($reporter->params) . DS . strtolower($groupTestName) . $this->getExtension('group');
+		$filePath = $this->_getTestsPath($reporter->params) . strtolower($groupTestName) . $this->getExtension('group');
 
 		if (!file_exists($filePath) || strpos($filePath, '..')) {
 			throw new InvalidArgumentException(sprintf(
@@ -169,8 +169,9 @@ public function runGroupTest($groupTestName, $reporter, $codeCoverage = false) {
 		}
 
 		require_once $filePath;
-		$suite = $this->getTestSuite(sprintf(__('%s group test', true), $groupTestName));
-		$groupClassName = Inflector::classify($groupTestName) . 'GroupTest';
+		$class = basename($groupTestName);
+		$suite = $this->getTestSuite(sprintf(__('%s group test', true), $class));
+		$groupClassName = Inflector::classify($class) . 'GroupTest';
 		$group = new $groupClassName();
 		$suite->addTestSuite($group);
 		if (isset($group->label)) {
@@ -361,6 +362,7 @@ protected static function _hasExpectedExtension($file, $extension) {
  * @static
  */
 	protected static function _getTestsPath($params) {
+		$result = null;
 		if (!empty($params['app'])) {
 			if ($params['show'] == 'cases' || !empty($params['case'])) {
 				$result = APP_TEST_CASES;
@@ -374,7 +376,7 @@ protected static function _getTestsPath($params) {
 				$_pluginBasePath = $pluginPath . DS . 'tests';
 			}
 			$result = $_pluginBasePath . DS . $type;
-		} else {
+		} elseif (!empty($params['show'])) {
 			if ($params['show'] == 'cases' || !empty($params['case'])) {
 				$result = CORE_TEST_CASES;
 			} else if ($params['show'] == 'groups') {