I am trying to figure out the best way to parameterise my Pester (V 5.3.3) testcases. The scenario is this. I would like to check that a list of logins exist on a group of database instances. My code is pretty repetitive, and looks like this:
Describe 'Check that logins exist' {
It "Check that <value> exists on <dbInstance>" -Tag "DEV" -TestCases @(
@{ Value = "login1"; dbInstance = 'dev01'}
@{ Value = "login2"; dbInstance = 'dev01'}
@{ Value = "login3"; dbInstance = 'dev01'}
) {
$login = Get-DbaLogin -sqlinstance $dbInstance -SqlCredential $cred -Login $Value
$login | Should -not -BeNullOrEmpty
}
It "Check that <value> exists on <dbInstance>" -Tag "SIT" -TestCases @(
@{ Value = "login1"; dbInstance = 'sit01'}
@{ Value = "login2"; dbInstance = 'sit01'}
@{ Value = "login3"; dbInstance = 'sit01'}
) {
$login = Get-DbaLogin -sqlinstance $dbInstance -SqlCredential $cred -Login $Value
$login | Should -not -BeNullOrEmpty
}
}
What I’d like to do is to parameterise that dbInstance value. That way, my code would look more like this:
Describe 'Check that logins exist' {
It "Check that <value> exists on <dbInstance>" -Tag "DEV" -TestCases @(
@{ Value = "login1"; dbInstance = #dbInstance#}
@{ Value = "login2"; dbInstance = #dbInstance#}
@{ Value = "login3"; dbInstance = #dbInstance#}
) {
$login = Get-DbaLogin -sqlinstance $dbInstance -SqlCredential $cred -Login $Value
$login | Should -not -BeNullOrEmpty
}
}
Then when I run my test, I’d like to pass multiple values to #dbInstance#, and then I’d like the code to run once per value passed to #dbInstance#. That way it doesn’t matter how many database instances I need to run it against, and I’m keeping code repetition to a minimum. Hopefully that makes sense. Anyone got any good ideas, or examples I could follow?
Thanks a lot!
>Solution :
If I understand your intent correctly, wrapping your test in a ForEach-Object pipeline as follows may work:
Describe 'Check that logins exist' {
# Provide the names of the DB instances as input.
'dev01', 'sit01' |
ForEach-Object {
$tag = $_.Substring(0, 3).ToUpper() # derive the -Tag value
# Note the use of $_ in the hashtables to refer to the instance at hand.
It "Check that <value> exists on <dbInstance>" -Tag $tag -TestCases @(
@{ Value = "login1"; dbInstance = $_ }
@{ Value = "login2"; dbInstance = $_ }
@{ Value = "login3"; dbInstance = $_ }
) {
$login = Get-DbaLogin -sqlinstance $dbInstance -SqlCredential $cred -Login $Value
$login | Should -not -BeNullOrEmpty
}
}
}