Reporting Pester Code Coverage Metrics to TeamCity

As previously mentioned I’ve been doing a lot of work with PowerShell modules at work where I have recently gotten all the parts for a full continuous delivery pipeline working for those modules. A big section of that pipeline runs through TeamCity and while the existing ability to have Pester test results show up in the build results is really great, code coverage is slightly less obvious but in the end fairly simple.

The trick is to use the -PassThru parameter with Invoke-Pester and then use TeamCity’s build reporting interaction to get the values into the system. The end result will look a lot like this:

$testResults = Invoke-Pester -OutputFile Test.xml -OutputFormat NUnitXml -CodeCoverage (Get-ChildItem -Path $PSScriptRoot\*.ps1 -Exclude *.Tests.* ).FullName -PassThru
Write-Output "##teamcity[buildStatisticValue key='CodeCoverageAbsLTotal' value='$($testResults.CodeCoverage.NumberOfCommandsAnalyzed)']"
Write-Output "##teamcity[buildStatisticValue key='CodeCoverageAbsLCovered' value='$($testResults.CodeCoverage.NumberOfCommandsExecuted)']"