Handle System using statements correctly

[tugberkugurlu]

When there is no System using statement or the class/struct is not under a System or System.* namespace, the current implementation is buggy:

Questions:

• Is there an Annotation like thing in roslyn to add which would indicate "add relevant using statements for this code fix"?

[sharwell]

You need to use the fully-qualified name, and then add Simplifier.Annotation.

[tugberkugurlu]

Doesn't work :disappointed:

Am I doing something wrong: https://github.com/DotNetAnalyzers/NullParameterCheckRefactoring/commit/91868474bd7512f395f6962851ccb7605505dad7?

[sharwell]

It looks like it's working to me, assuming it inserts just ArgumentNullException when the file does contain a using System; declaration.

[tugberkugurlu]

Weird, I cannot get it working in my box. It always adds it as System.ArgumentNullException if I don't have a using statement for System. Is this the right place to add Simplifier.Annotation: https://github.com/DotNetAnalyzers/NullParameterCheckRefactoring/commit/91868474bd7512f395f6962851ccb7605505dad7#diff-cdeec3cc19b47b81331208ac85ae1c83R107?

[sharwell]

The important part is that it always inserts a valid reference to System.ArgumentNullException. You also want it to use the shortest form available during the code fix. For now you probably won't get it to automatically insert the using System; statement, but this is arguably a bad idea anyway (perhaps the user omitted it on purpose).