Assertion over each item in collection in Pester - powershell

Question

I am doing some infrastructure testing in Pester and there is repeating scenario that I don't know how to approach.
Let's say, I want to check whether all required web roles are enabled on IIS. I have a collection of required web roles and for each of them I want to assert it is enabled.
My current code looks like this:
$requiredRoles = #(
"Web-Default-Doc",
"Web-Dir-Browsing",
"Web-Http-Errors",
"Web-Static-Content",
"Web-Http-Redirect"
)
Context "WebRoles" {
It "Has installed proper web roles" {
$requiredRoles | % {
$feature = Get-WindowsOptionalFeature -FeatureName $_ -online
$feature.State | Should Be "Enabled"
}
}
}
It works in the sense that the test will fail if any of the roles are not enabled/installed. But that is hardly useful if the output of such Pester test looks like this:
Context WebRoles
[-] Has installed proper web roles 2.69s
Expected: {Enabled}
But was: {Disabled}
283: $feature.State | Should Be "Enabled"
This result doesn't give any clue about which feature is the Disabled one.
Is there any recommended practice in these scenarios? I was thinking about some string manipulation...
Context "WebRoles" {
It "Has installed proper web roles" {
$requiredRoles | % {
$feature = Get-WindowsOptionalFeature -FeatureName $_ -online
$toCompare = "{0}_{1}" -f $feature.FeatureName,$feature.State
$toCompare | Should Be ("{0}_{1}" -f $_,"Enabled")
}
}
}
which would output:
Context WebRoles
[-] Has installed proper web roles 2.39s
Expected string length 27 but was 28. Strings differ at index 20.
Expected: {IIS-DefaultDocument_Enabled}
But was: {IIS-DefaultDocument_Disabled}
-------------------------------^
284: $toCompare | Should Be ("{0}_{1}" -f $_,"Enabled")
...which is better, but it doesn't feel very good...
Also, there is second problem with the fact that the test will stop on first fail and I would need to re-run the test after I fix each feature...
Any ideas?

Answer 1

Put your It inside the loop like so:
Context "WebRoles" {
$requiredRole | ForEach-Object {
It "Has installed web role $_" {
(Get-WindowsOptionalFeature -FeatureName $_ -online).State | Should Be "Enabled"
}
}
}