What test cases should I include in order to test the diagrams that have been migrated from gliffy to draw.io i.e to check if the have migrated successfully and nothing was missed
The macro usage admin page will tell you how many gliffy macros are remaining. The migration log will also list any issues.
Check out the page Diagramming in Confluence - Mass import from Gliffy to draw.io.
You can find info on:
Hope that helps!
Fore more general info on draw.io for Confluence or Jira, please refer to our draw.io webpage.
And some great blogposts! Blog - draw.io