Output testing for own functions

Question

I have a function which returns the contents of the a config file:

function Get-VA.Settings {
<#
.SYNOPSIS
Fetches settings from a XML file
.DESCRIPTION
Fetches settings from a XML file and outputs a XML Object
.EXAMPLE
Get-VA.Settings -path <path-to-config-file> -Rollback <path-to-rollback-file>
#>
  Param (
    [Parameter(Mandatory=$true,Position=0)]
    [string]$path,
    [Parameter(Mandatory=$true,Position=1)]
    [string]$Rollback
  )
  try {
    [xml]$config = Get-Content -Path $path
    Write-Output -InputObject $config
  } catch {
    Write-VA.EventLog -Message ("Could not load Configuration File: `r`n" + $Error) -Id 11 -type Error
    Invoke-VA.Rollback -Path $($Rollback)
  }
}

Now I have a test in Pester which just check if the funtion actually returns something:

Import-Module ($PSScriptRoot + "\utility.psm1")
Describe "Settings Module" {
  InModuleScope utility {
    Context "Get-VA.Settings" {
      It "should have Help and Examples" {
        $helpinfo = Get-Help Get-VA.Settings
        $helpinfo.examples | should not BeNullOrEmpty # should have examples
        $helpinfo.details | should not BeNullOrEmpty # should have Details
        $helpinfo.description | Should not BeNullOrEmpty # Should have a Description for the Function
      }

      It "should fail safely on read Error" {
        Mock Get-Content {throw}
        Mock Write-VA.EventLog { }
        Mock Invoke-VA.Rollback { }
        Get-VA.Settings -path "1" -Rollback "1"
        Assert-MockCalled Invoke-VA.Rollback -Times 1
      }

      It "should return a value" {
        Set-Content -Value "<xml><foo>bar</foo></xml>" -Path "settings-test.ps1" 
        Get-VA.Settings -path .\settings-test.ps1 -Rollback "1" | should not BeNullOrEmpty
        Remove-Item "settings-test.ps1"
      }
    }
  }
}

Now whatever I do to output the configuration settings I can't seem to pass the test with Pester even tough the function properly runs.

[-] should return a value 18ms
Expected: value to not be empty
Get-ConfigSettings -path .\settings-test.ps1 -Rollback "1" | should not BeNullOrEmpty

Am I missing something here? How do I handle function output properly then?

Answer 1

Get-Help Context

Any Mocks defined inside a Context are removed at the end of the Context scope,

Since It "should fail safely on read Error"(1) and It "should return a value"(2) belong to same Context block, Mock Get-Content {throw} defined in (1) still have effect in (2), so that Get-VA.Settings does not call Get-Content cmdlet, but call mock instead.