File created by Microsoft Visual Studio, a program used by software developers to create Windows applications and other software; contains configuration information for a test project, including the set of roles required for the application being tested, the role used to run the tests, and diagnostic data adapters for each role.

Developers use test settings files to specify diagnostic data adapters, which collect different types of data during test execution. To create a test settings file in Visual Studio 2010, create a test project, right-click on the "Solution Items" folder in the Solution Explorer, select Add → New Item..., and then choose Test Settings. NOTE: Microsoft introduced TESTSETTINGS files with Visual Studio 2010. Visual Studio 2008 and earlier use the .TESTRUNCONFIG extension.