If you type an arbitrary character, then delete it immediately, does the extra whitespace stay in place when you move the cursor away?
yes, the spaces remain.
If it does, you may resort to adding a placeholder comment, like: function MyFunc() { /* TODO: code needed here */ };
you mean just add several character using a quick-key map? but then everytime i type the code before "/* TODO: code needed here */", i have to delete it. can i change the default behavior of vim not to delete the indent?