What is the .idea folder?

Question

What is the .idea folder and what is it used for?

Answer

The .idea folder (hidden on OS X) in the solution root contains IntelliJ’s project-specific settings files. These include per-project details such as VCS mapping and run and debug configurations, as well as per-user details, such as currently open files, navigation history and currently selected configuration.

Some files should be committed to source control, some should be excluded. Usually, one needs to share the following:

• indexLayout.xml - this file is for the information about external folders attached to the solution, which are not the part of a .NET project. Such folders can be added via right-click on a solution -> “Attach Existing Folder...”.
• vcs.xml - this file is for VCS-related internal information, as which VCS is enabled, etc.
• runConfigurations - this folder is for shared run configurations.

Other files inside the .idea folder can be safely excluded from VCS (ex. modules.xml and riderModule.iml), as Rider can generate them again.

Refer to this JetBrains.gitignore on GitHub to see what exactly should be ignored.