Output debug information from pester test - output

Question

I'm writing a system in C# that has lots of features to test. One feature is a set of PowerShell custom cmdlets for managing my system.
I'm using pester (v5) to test my cmdlets and will have a lot of test cases for the many scenarios that I want to test.
I can use pester successfully but I can't get any debug output from the tests - only the test report. The test report is fine to see what's passing and failing but if I have a failure then I want to be able to output results that can give me the context of what is going wrong.
I've tried all the settings I can think of for PesterConfiguration to no avail, e.g.
$PesterPreference = [PesterConfiguration]::Default
#$PesterPreference.Output.Verbosity = "Diagnostic"
$PesterPreference.Debug.WriteDebugMessages = $true
#$PesterPreference.Debug.WriteDebugMessagesFrom = "*"
As an example, imagine I have a get-foo cmdlet that returns an object with a Thing property that should have a value of "Bar".
I can write a pester test to check this but I would like to be able to output the returned object as part of the test to see something like:
Name Value
---- -----
Thing Bar
Other 124
Describe 'Test My CmdLet' {
It 'get-foo should return bar' {
$obj = get-foo
write-output $obj
$obj | Should -Not -BeNullOrEmpty
$obj.Thing | Should -Be "Bar"
}
}
Without the ability to get output then I have to reconstruct the test setup and structure outside of pester directly in PowerShell - which is a painful process.
If anyone has any advice on how to get my output then I'd appreciate the advice.
Thanks,
David

Answer 1

The answer seems to be to set the $VerbosePreference="Continue" in the script
E.g.
$VerbosePreference = "Continue"
Describe 'Test My CmdLet' {
It 'get-foo should return bar' {
$obj = get-foo
$obj | out-string | write-verbose
$obj | Should -Not -BeNullOrEmpty
$obj.Thing | Should -Be "Bar"
}
}
Will dump out the detail of $obj as expected. This also works with $DebugPreference, $InformationPeference etc.

Answer 2

You can access StandardOutput per test by using the result-object you get with -PassThru. Demo:
# Just using a container here to avoid creating a testfile
$container = New-PesterContainer -ScriptBlock {
Describe 'Test My CmdLet' {
It 'get-foo should return bar' {
function get-foo { 1..3 | % { "hello $_" } }
$obj = get-foo
write-output $obj
$obj | Should -Not -BeNullOrEmpty
}
}
}
$pesterResult = Invoke-Pester -Container $container -PassThru
$pesterResult.tests | Format-Table ExpandedPath, StandardOutput
ExpandedPath StandardOutput
------------ --------------
Test My CmdLet.get-foo should return bar {hello 1, hello 2, hello 3}

Answer 3

I couldn't find any configuration option to show the same I would see on the console so I'm using the PassThru and a for loop to print all the tests output afterwards:
$(Invoke-pester -PassThru).Tests | ForEach-Object -Process {"-"*80;$_.Result + ": " + $_.Name;"-"*80;$_.StandardOutput}