magento#4292: Ability to sitch to default mode

- mode can be switched back to default w/o throving an error

Author: Etty

app/code/Magento/Deploy/Console/Command/SetModeCommand.php

@@ -101,6 +101,9 @@ protected function execute(InputInterface $input, OutputInterface $output)
                         $modeController->enableProductionMode();
                     }
                     break;
+                case State::MODE_DEFAULT:
+                    $modeController->enableDefaultMode();
+                    break;
                 default:
                     throw new LocalizedException(__('Cannot switch into given mode "%1"', $toMode));
             }

app/code/Magento/Deploy/Model/Mode.php

@@ -177,6 +177,25 @@ public function enableDeveloperMode()
         $this->setStoreMode(State::MODE_DEVELOPER);
     }
 
+    /**
+     * Enable Default mode
+     *
+     * @return void
+     */
+    public function enableDefaultMode()
+    {
+        $this->filesystem->cleanupFilesystem(
+            [
+                DirectoryList::CACHE,
+                DirectoryList::GENERATED_CODE,
+                DirectoryList::GENERATED_METADATA,
+                DirectoryList::TMP_MATERIALIZATION_DIR,
+                DirectoryList::STATIC_VIEW,
+            ]
+        );
+        $this->setStoreMode(State::MODE_DEFAULT);
+    }
+
     /**
      * Get current mode information
      *

app/code/Magento/Deploy/Test/Unit/Console/Command/SetModeCommandTest.php

@@ -67,6 +67,18 @@ public function testSetDeveloperMode()
         );
     }
 
+    public function testSetDefaultMode()
+    {
+        $this->modeMock->expects($this->once())->method('enableDefaultMode');
+
+        $tester = new CommandTester($this->command);
+        $tester->execute(['mode' => 'default']);
+        $this->assertContains(
+            "default mode",
+            $tester->getDisplay()
+        );
+    }
+
     public function testSetProductionSkipCompilation()
     {
         $this->modeMock->expects($this->once())->method('enableProductionModeMinimal');