search

sillsdev / solid

Solid is a software tool that can be used to check, clean up, and convert Standard Format (e.g. Toolbox) lexicon data.
MIT License
0 stars 2 forks source link

Fix some "nullable reference type" warnings #26

Open rmunn opened 1 week ago

rmunn commented 1 week ago

This fixes some of the compiler warnings about nullable reference types that you get when you build this with a modern C# compiler. It doesn't fix nearly all of them, because I realized that a lot of these can't be easily fixed as long as the project is targeting net461. For example, this section of code produces a compiler warning on line 276 that switchToCitationForm might be null:

https://github.com/sillsdev/solid/blob/96dc3322a1b3514c43bedea07b354b3ba86b65f8/src/SolidGui/QuickFixer.cs#L269-L276

It's immediately obvious that switchToCitationForm cannot be null on line 276, but the compiler doesn't know that as long as the target framework is net461. That's because the annotations that tell the compiler "If this function returns true/false, then its parameter can/cannot be null" were added to library code sometime during the .NET Core / .NET 5 era, and the net461 framework libraries don't have those annotations. So the compiler can't infer anything about the nullness of the parameter to string.IsNullOrEmpty, and therefore it gives a warning. You could suppress it by using the ! operator, as I did in this particular case, but doing that everywhere is tedious. And ultimately pointless, when switching to a more modern .NET target will end up fixing the issue anyway.

Therefore, I suggest postponing the rest of this work until after the code is switched to target a more modern version of .NET, say 6 or 8. At that point many of the compiler warnings will go away, and the ones that are left will be ones actually worth fixing.

megahirt commented 1 week ago

After some discussion in the office, we will hold off on merging this until we can understand more about the effort it will take to upgrade to .Net 8 windows forms. Upgrading will eliminate some compiler warnings and reveal the ones that are actually a problem.