I agree. Partial classes are for supplementing machine-generated code: winforms designer files, generated entity framework classes etc.
That is, wherever the IDE would overwrite any edits you made. I'm currently refactoring a 3 partial class monster usercontrol: 238 lines, 2370 lines, and 4526 lines. Fun.
Maybe this says more about the quality of the code I have to work on or my own lack of ability.
Our legacy code often comes along with a large number of interfaces and dependency injection and it's difficult to find where the code actually 'does something'. So the only way I can understand what the code is doing is by stepping through it in a debugger.
If I just try to read it, I end up half a dozen classes away from the method I'm trying to understand in no time.
That is, wherever the IDE would overwrite any edits you made. I'm currently refactoring a 3 partial class monster usercontrol: 238 lines, 2370 lines, and 4526 lines. Fun.