MAGETWO-38180: Check if the theme is not a base for any virtual theme

 - Code style fixed
 - Move ChildVirtualTheme checking mechanism after validation() to avoid cyclomatic complexity and n-path complexity.
  - Remove unused objectManager member in test case
  - Test cases added to cover ChildVirtualTheme check.

Author: Fred Sung

app/code/Magento/Theme/Console/Command/ThemeUninstallCommand.php

@@ -197,6 +197,11 @@ protected function execute(InputInterface $input, OutputInterface $output)
             $output->writeln($validationMessages);
             return;
         }
+        $childVirtualThemeCheckMessages = $this->checkChildVirtualTheme($themePaths);
+        if (!empty($childVirtualThemeCheckMessages)) {
+            $output->writeln($childVirtualThemeCheckMessages);
+            return;
+        }
         $dependencyMessages = $this->checkDependencies($themePaths);
         if (!empty($dependencyMessages)) {
             $output->writeln($dependencyMessages);
@@ -240,7 +245,6 @@ private function validate($themePaths)
         $messages = [];
         $unknownPackages = [];
         $unknownThemes = [];
-        $themeHasChildren = [];
         $installedPackages = $this->composer->getRootRequiredPackages();
         foreach ($themePaths as $themePath) {
             if (array_search($this->getPackageName($themePath), $installedPackages) === false) {
@@ -249,17 +253,6 @@ private function validate($themePaths)
             if (!$this->themeCollection->hasTheme($this->themeCollection->getThemeByFullPath($themePath))) {
                 $unknownThemes[] = $themePath;
             }
-            else {
-                $theme = $this->themeProvider->getThemeByFullPath($themePath);
-                if($theme->hasChildThemes())
-                    $themeHasChildren[] = $themePath;
-            }
-        }
-        if(!empty($themeHasChildren)) {
-            $text = count($themeHasChildren) > 1 ?
-                ' are bases of' : ' is a base of';
-            $messages[] = '<error>Unable to delete. '
-                . implode(', ', $themeHasChildren) . $text . ' virtual theme</error>';
         }
         $unknownPackages = array_diff($unknownPackages, $unknownThemes);
         if (!empty($unknownPackages)) {
@@ -299,6 +292,31 @@ private function checkDependencies($themePaths)
         return $messages;
     }
 
+    /**
+     * Check theme if has child virtual theme
+     *
+     * @param string[] $themePaths
+     * @return string[] $messages
+     */
+    private function checkChildVirtualTheme($themePaths)
+    {
+        $messages = [];
+        $themeHasChildren = [];
+        foreach ($themePaths as $themePath) {
+            $theme = $this->themeProvider->getThemeByFullPath($themePath);
+            if ($theme->hasChildThemes()) {
+                $themeHasChildren[] = $themePath;
+            }
+        }
+        if (!empty($themeHasChildren)) {
+            $text = count($themeHasChildren) > 1 ?
+                ' are bases of' : ' is a base of';
+            $messages[] = '<error>Unable to delete. '
+                . implode(', ', $themeHasChildren) . $text . ' virtual theme</error>';
+        }
+        return $messages;
+    }
+
     /**
      * Get package name of a theme by its full theme path
      *

app/code/Magento/Theme/Test/Unit/Console/Command/ThemeUninstallCommandTest.php

@@ -26,11 +26,6 @@ class ThemeUninstallCommandTest extends \PHPUnit_Framework_TestCase
      */
     private $maintenanceMode;
 
-    /**
-     * @var \Magento\Framework\ObjectManagerInterface|\PHPUnit_Framework_MockObject_MockObject
-     */
-    private $objectManager;
-
     /**
      * @var \Magento\Framework\Filesystem|\PHPUnit_Framework_MockObject_MockObject
      */
@@ -204,8 +199,7 @@ public function testExecuteFailedValidationMixed()
                 [
                     ['test1/composer.json', null, null, '{"name": "dummy1"}'],
                     ['test2/composer.json', null, null, '{"name": "magento/theme-b"}'],
-                    ['test4/composer.json', null, null, '{"name": "dummy2"}'],
-                    ['test5/composer.json', null, null, '{"name": "magento/theme-b"}']
+                    ['test4/composer.json', null, null, '{"name": "dummy2"}']
                 ]
             ));
         $dirRead->expects($this->any())
@@ -215,8 +209,7 @@ public function testExecuteFailedValidationMixed()
                     ['test1/composer.json', true],
                     ['test2/composer.json', true],
                     ['test3/composer.json', false],
-                    ['test4/composer.json', true],
-                    ['test5/composer.json', true]
+                    ['test4/composer.json', true]
                 ]
             ));
         $this->collection->expects($this->any())
@@ -226,17 +219,11 @@ public function testExecuteFailedValidationMixed()
         $this->collection->expects($this->at(3))->method('hasTheme')->willReturn(true);
         $this->collection->expects($this->at(5))->method('hasTheme')->willReturn(false);
         $this->collection->expects($this->at(7))->method('hasTheme')->willReturn(true);
-        $this->collection->expects($this->at(9))->method('hasTheme')->willReturn(true);
         $this->filesystem->expects($this->any())
             ->method('getDirectoryRead')
             ->with(DirectoryList::THEMES)
             ->willReturn($dirRead);
-        $theme = $this->getMock('Magento\Theme\Model\Theme', [], [], '', false);
-        $theme->expects($this->at(1))->method('hasChildThemes')->willReturn(false);
-        $theme->expects($this->at(2))->method('hasChildThemes')->willReturn(false);
-        $theme->expects($this->at(3))->method('hasChildThemes')->willReturn(true);
-        $this->themeProvider->expects($this->any())->method('getThemeByFullPath')->willReturn($theme);
-        $this->tester->execute(['theme' => ['test1', 'test2', 'test3', 'test4', 'test5']]);
+        $this->tester->execute(['theme' => ['test1', 'test2', 'test3', 'test4']]);
         $this->assertContains(
             'test1, test4 are not installed composer packages',
             $this->tester->getDisplay()
@@ -249,10 +236,6 @@ public function testExecuteFailedValidationMixed()
             'Unknown theme(s): test3' . PHP_EOL,
             $this->tester->getDisplay()
         );
-        $this->assertContains(
-            'test5 is a base of virtual theme',
-            $this->tester->getDisplay()
-        );
     }
 
     public function setUpPassValidation()
@@ -274,14 +257,45 @@ public function setUpPassValidation()
             ->method('getThemeByFullPath')
             ->willReturn($this->getMockForAbstractClass('Magento\Framework\View\Design\ThemeInterface', [], '', false));
         $this->collection->expects($this->any())->method('hasTheme')->willReturn(true);
+    }
+
+    public function setupPassChildVirtualThemeCheck()
+    {
         $theme = $this->getMock('Magento\Theme\Model\Theme', [], [], '', false);
         $theme->expects($this->any())->method('hasChildThemes')->willReturn(false);
         $this->themeProvider->expects($this->any())->method('getThemeByFullPath')->willReturn($theme);
     }
 
+    public function testExecuteFailedChildVirtualThemeCheck()
+    {
+        $this->setUpPassValidation();
+        $theme = $this->getMock('Magento\Theme\Model\Theme', [], [], '', false);
+        $theme->expects($this->any())->method('hasChildThemes')->willReturn(true);
+        $this->themeProvider->expects($this->any())->method('getThemeByFullPath')->willReturn($theme);
+        $this->tester->execute(['theme' => ['frontend/Magento/a']]);
+        $this->assertContains(
+            'Unable to delete. frontend/Magento/a is a base of virtual theme',
+            $this->tester->getDisplay()
+        );
+    }
+
+    public function testExecuteFailedMultipleChildVirtualThemeCheck()
+    {
+        $this->setUpPassValidation();
+        $theme = $this->getMock('Magento\Theme\Model\Theme', [], [], '', false);
+        $theme->expects($this->any())->method('hasChildThemes')->willReturn(true);
+        $this->themeProvider->expects($this->any())->method('getThemeByFullPath')->willReturn($theme);
+        $this->tester->execute(['theme' => ['frontend/Magento/a', 'frontend/Magento/b']]);
+        $this->assertContains(
+            'Unable to delete. frontend/Magento/a, frontend/Magento/b are bases of virtual theme',
+            $this->tester->getDisplay()
+        );
+    }
+
     public function testExecuteFailedDependencyCheck()
     {
         $this->setUpPassValidation();
+        $this->setupPassChildVirtualThemeCheck();
         $this->dependencyChecker->expects($this->once())
             ->method('checkDependencies')
             ->willReturn(['magento/theme-a' => ['magento/theme-b', 'magento/theme-c']]);