In this page of ReSharper options, you can adjust unit testing settings related to xUnit.net tests.
|Enable xUnit.net support|
By default, ReSharper adds action indicators allowing you to execute xUnit.net tests right from the editor and automatically discovers xUnit.net tests in your solution. Clear this checkbox to disable this behavior.
|xUnit.net config file|
ReSharper will try to find and load your xUnit.net configuration file in any of standard locations. If your configuration file is in a custom location, select Use specific configuration file and specify the path to this file. To learn about the format of the configuration files, see configuring xUnit.net with JSON and configuring xUnit.net with XML