Platform design creation fails if Java class already exists

[anssit]

Steps to reproduce

Create new platform design main-view.html in the base starter from vaadin.com/start. Choose to create a java file in the main package of the application (where MainView class already exists.)

Actual behavior

Cannot create file '/Users/anssit/_designerteam/projects/designer-test-data/flow-app/src/main/java/com/vaadin/starter/skeleton/MainView.java'. File already exists.
com.intellij.util.IncorrectOperationException: Cannot create file '/Users/anssit/_designerteam/projects/designer-test-data/flow-app/src/main/java/com/vaadin/starter/skeleton/MainView.java'. File already exists.
	at com.intellij.psi.impl.file.PsiDirectoryImpl.checkName(PsiDirectoryImpl.java:488)
	at com.intellij.psi.impl.file.PsiDirectoryImpl.checkAdd(PsiDirectoryImpl.java:477)
	at com.intellij.psi.impl.file.PsiJavaDirectoryImpl.checkAdd(PsiJavaDirectoryImpl.java:79)
	at com.intellij.psi.impl.file.PsiDirectoryImpl.add(PsiDirectoryImpl.java:411)
	at com.intellij.psi.impl.file.PsiJavaDirectoryImpl.add(PsiJavaDirectoryImpl.java:64)
	at com.vaadin.designer2.intellij.util.PsiUtil.createFile(PsiUtil.java:179)
	at com.vaadin.designer2.intellij.actions.flow.CreateFlowAction.createJavaCompanion(CreateFlowAction.java:168)
	at com.vaadin.designer2.intellij.actions.flow.CreateFlowAction.create(CreateFlowAction.java:134)
	at com.vaadin.designer2.intellij.actions.AbstractCreationAction$1.run(AbstractCreationAction.java:62)
	at com.intellij.openapi.application.RunResult.run(RunResult.java:35)
	at com.intellij.openapi.command.WriteCommandAction$2.run(WriteCommandAction.java:108)
	at com.intellij.openapi.command.impl.CoreCommandProcessor.executeCommand(CoreCommandProcessor.java:124)
	at com.intellij.openapi.command.impl.CoreCommandProcessor.executeCommand(CoreCommandProcessor.java:99)
	at com.intellij.openapi.command.WriteCommandAction.performWriteCommandAction(WriteCommandAction.java:103)
	at com.intellij.openapi.command.WriteCommandAction.access$000(WriteCommandAction.java:34)
	at com.intellij.openapi.command.WriteCommandAction$1.run(WriteCommandAction.java:85)
	at com.intellij.openapi.application.impl.ApplicationImpl.invokeAndWait(ApplicationImpl.java:723)
	at com.intellij.openapi.command.WriteCommandAction.execute(WriteCommandAction.java:82)
	at com.vaadin.designer2.intellij.actions.AbstractCreationAction.showDialog(AbstractCreationAction.java:64)
	at com.vaadin.designer2.intellij.actions.AbstractCreationAction.showCreateDesignDialog(AbstractCreationAction.java:49)
	at com.vaadin.designer2.intellij.actions.flow.CreateFlowAction.actionPerformed(CreateFlowAction.java:100)
	at com.intellij.openapi.actionSystem.ex.ActionUtil.performActionDumbAware(ActionUtil.java:191)
	at com.intellij.openapi.actionSystem.impl.ActionMenuItem$ActionTransmitter$1.run(ActionMenuItem.java:311)
	at com.intellij.openapi.wm.impl.FocusManagerImpl.runOnOwnContext(FocusManagerImpl.java:958)
	at com.intellij.openapi.wm.impl.IdeFocusManagerImpl.runOnOwnContext(IdeFocusManagerImpl.java:124)
	at com.intellij.openapi.actionSystem.impl.ActionMenuItem$ActionTransmitter.actionPerformed(ActionMenuItem.java:281)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
	at com.intellij.openapi.actionSystem.impl.ActionMenuItem.fireActionPerformed(ActionMenuItem.java:109)
	at com.intellij.ui.plaf.beg.BegMenuItemUI.doClick(BegMenuItemUI.java:513)
	at com.intellij.ui.plaf.beg.BegMenuItemUI.access$300(BegMenuItemUI.java:45)
	at com.intellij.ui.plaf.beg.BegMenuItemUI$MyMenuDragMouseHandler.menuDragMouseReleased(BegMenuItemUI.java:560)
	at javax.swing.JMenuItem.fireMenuDragMouseReleased(JMenuItem.java:586)
	at javax.swing.JMenuItem.processMenuDragMouseEvent(JMenuItem.java:483)
	at javax.swing.JMenuItem.processMouseEvent(JMenuItem.java:429)
	at javax.swing.MenuSelectionManager.processMouseEvent(MenuSelectionManager.java:329)
	at com.intellij.ui.plaf.beg.BegMenuItemUI$MyMouseInputHandler.mouseReleased(BegMenuItemUI.java:535)
	at java.awt.Component.processMouseEvent(Component.java:6533)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
	at java.awt.Component.processEvent(Component.java:6298)
	at java.awt.Container.processEvent(Container.java:2236)
	at java.awt.Component.dispatchEventImpl(Component.java:4889)
	at java.awt.Container.dispatchEventImpl(Container.java:2294)
	at java.awt.Component.dispatchEvent(Component.java:4711)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
	at java.awt.Container.dispatchEventImpl(Container.java:2280)
	at java.awt.Window.dispatchEventImpl(Window.java:2746)
	at java.awt.Component.dispatchEvent(Component.java:4711)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
	at java.awt.EventQueue$4.run(EventQueue.java:731)
	at java.awt.EventQueue$4.run(EventQueue.java:729)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:857)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:654)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:386)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

Expected behavior

Wizard cannot be completed if the class already exists in that location.

IDE, Designer and OS version

Designer 4.0.0.beta1, at least IDEA. Check Eclipse too.

[anssit]

Not a problem in Eclipse.