Daily Archives: October 9, 2018

Pester Mocking, ParameterFilters and Write-Output

I just spend an annoyed 45 minutes or so puzzling over a Pester test I was writing. I needed to test an if/elseif/else branching block of PowerShell code, written by someone else, which did very similar things to install powershell modules, uninstall, reinstall, or not, depending on some evaluated conditions and based on a list of modules and their versions

The final else condition was, in essence, not doing anything other than writing to the output stream to say “I’m not doing anything at this point”, so obviously I figured I could use Assert-MockCalled on Write-Output and I’d know what path the code was going down and I’d be sorted.

Anything but. Continue reading →