How to create unit test for WIX installer (msi database)

If we want to test installer in WIX technology we can use API from Microsoft.Deployment.WindowsInstaller.dll which is included to WiX Toolset. Below is manual step by step how to test installer database for attached files.

1 Use WiX Toolset v3.6\bin\Microsoft.Deployment.WindowsInstaller.dll and decompile by .dotPeek (it's free) and browse Database class. Now you can execute SELECT query on installer database.
2 Create unit test project, for example for NUnit test framework.
3 Add reference to dll WiX Toolset v3.6\bin\Microsoft.Deployment.WindowsInstaller.dll
4 Create NUnit Test and add to test "Database database = new Database(path to msi, DatabaseOpenMode)
List listFiles = (database.ExecuteNonQuery("select 'FileName' from 'File' ")).Cast().ToList();”

5 Check expected file names in your WIX installer(like .wxs, wxi) with list listFiles. Data could be extracted from .wxs, .wxi by .Net xmlDoc class to read XML and next by foreach to compare file name with above listFiles.

Now you have unit test to check your files names from WIX Installer .wxs,.wxi configuration with compiled installer MSI.
The described unit test How To for WIX is only one of the ideas to test functionality of installer because we can also create unit test for custom actions or use Wix Lux.


dotPeek web site
WIX Lux
Useless WIX unit test example