Hello Eng Keat,

Test Studio project is a complex strucutre of files which work together. The changes applied in the test may actually reflect on more than one file. Therefore Test Studio prompts for saving unsaved changes on closing the complete project.

In the meantime, while the changes are still not saved, the test remains bold (dirty) in the Project Explorer. At any time in between you can use the Ctrl+S keyboard shortcut to save the current item on focus and the Ctrl+Shift+S keyboard shortcut to save all. 

On project close there's a Save File prompt where you can choose the files to save. Adding an additional save dialog on closing each tab (for opened test or code-behind) doesn's sound convenient from user experience perspective. Also this would be a significant change in the workflow established so far. Therefore I will encourage you to try using the keyboard shortcuts to save recent changes to ease you in working on the project.

If it comes to changes you don't want to keep, the only possible approach remains the option to close the entire project and choose the files you want to save and which you want to discard. 

Regards,
Elena
Progress Telerik