Inactive preprocessor branches will be ignored during refactoring

Problem

This issue impacts both ReSharper and Rider

Inactive preprocessor branches are not taken into account on Refactoring. For example, consider the following dependency injection configuration of an ASP.NET program:

using Microsoft.Extensions.Logging;

// some code ...
#if DEBUG
            options.EnableSensitiveDataLogging();
#else
            options.LogTo(System.Console.WriteLine, LogLevel.None);
#endif

If the current launch profile is Release, code inspection will suggest deleting the unused using Microsoft.Extensions.Logging; . It will cause issue if the program is on Release.

The same issue happens on Unity as well, like using #if UNITY_WEBGL, #if UNITY_EDITOR, etc.

Cause [Optional]

ReSharper (Rider ReSharper backend) will respect the preprocessor settings of the current context. It causes the unused preprocessor will not be taken during analysis. It's a critical issue impacted R#/Rider basic implementation.

Resolution

A workaround is enclosing the mis-refactoring context with the same preprocessor directives, R#/Rider will skip the code during Code Cleanup. For example, the previous code sample:

#if DEBUG
using Microsoft.Extensions.Logging;
#endif

// some code ...

#if DEBUG
            options.EnableSensitiveDataLogging();
#else
            options.LogTo(System.Console.WriteLine, LogLevel.None);
#endif