tolgaumut,
Thank you for bringing this to our notice. I am able to reproduce this at my end. When a .js file is opened, it opens by default in MyEclipse JavaScript Editor, now if you try the short cut key for Open Type, the open type window doesn’t open. Whereas, if you open a .js file in text editor and try the shortcut key, it opens the Open Type window. I have filed a PR for the dev team.