...
So for a plugin it boils down to 4 points:
*1 Write a ignored (not run on BS) test that can create a dsproj file with all persistent objects you have in your plugin. You create a 'representative' project here. Update this test as your plugin evolves and add the category **\the category [BackwardCompatibility\]* Wiki Markup
*2 If you have a release with file-format changes run test 1) and copy the result to the release version. Write a test that reads in that project file and add the category \the category [BackwardCompatibility\]* Wiki Markup
For example if you release 1.1 you should run the test of 1) and copy the result to project1_1.dsproj + data. Check in this project and write a test ReadVersion1_1 that reads this project. You will never change this checked in project again.
...