Use StyleCop styles
To apply StyleCop rules, JetBrains Rider relies on its own features and settings, which do not always map directly onto StyleCop rules:
JetBrains Rider supports most of StyleCop naming, maintainability, readability, and layout rules.
Some StyleCop rules may not be supported in a specific version of JetBrains Rider. However we will try to support more rules in coming versions.
Inspections for StyleCop rules
JetBrains Rider provides a number of code inspections for formatting and syntax style rules. These inspections do not find all code style problems that StyleCop finds, but they also can find some other problems that StyleCop cannot find, such as indenting problems.
As of version 2018.1, formatter inspections are disabled by default, but they will be automatically activated as soon as you enable StyleCop settings, and will offer you quick-fixes for code issues to automatically correct detected problems.
Apply settings from StyleCop files
By default, JetBrains Rider does not read settings from StyleCop files (RuleSet and Settings.StyleCop). To start taking these settings into account, select the Enable StyleCop support checkbox on the page of JetBrains Rider settings Ctrl+Alt+S and choose which StyleCop file format should be used. Make sure that Read settings from editorconfig, project settings and rule sets on the page of JetBrains Rider settings is selected.
When StyleCop integration is enabled, settings from StyleCop files (RuleSet and Settings.StyleCop) will override JetBrains Rider code formatting and code syntax styles, and enable corresponding code inspections.
If you use EditorConfig and StyleCop configuration files simultaneously, the EditorConfig settings will always take precedence over both StyleCop and JetBrains Rider settings. This means that if settings from StyleCop files (RuleSet and Settings.StyleCop) do not give desired results, you can always override specific settings using EditorConfig properties.
Yet another way to apply StyleCop rules in your code is by using StyleCop Analyzers for the .NET Compiler Platform instead of StyleCop. To harness these analyzers, enable the .NET compiler platform analyzers in JetBrains Rider and then install the corresponding analyzer package.