Test array of values in a loop of assertions?

[cra...@gmail.com]

Assuming a simple command:

# Invoke-Foo.ps1
function invoke-foo {
    param(
        [int]$Value
    )
    $value * 2
}

Is this an acceptable way to test multiple values:

# Invoke-Foo.Tests.ps1
$here = Split-Path -Parent $MyInvocation.MyCommand.Path
$sut = (Split-Path -Leaf $MyInvocation.MyCommand.Path).Replace(".Tests.", ".")
. "$here\$sut"

Describe "invoke-foo" {

    $Orignals=@(2,4,6)

    $current=$null

    BeforeEach {
        Write-Host 'BeforeEach'
        Write-Host "Current: $Current"
    }
    AfterEach {
        Write-Host 'AfterEach'
        Write-Host "Current: $Current"
    }

    $Orignals | % {
        $current=$_
        It "Should return $_ x 2" {
       
            $Actual = Invoke-Foo $current

            $Actual | Should Be ($current*2)

        }

    }
}

I'm especially interested in utilizing the `BeforeEach` and `AfterEach` block with the value being tested in the `It` block.

Is there a more-efficient way to do so?

[Dave Wyatt]

You can write your own loops like that, if you want.  You can also use the -TestCases parameter of the It command, which looks something like this:

Describe "invoke-foo" {

    $testCases = @(
        @{ Value = 2; ExpectedResult = 4 }
        @{ Value = 4; ExpectedResult = 8 }
        @{ Value = 6; ExpectedResult = 12 }
    )

    It "Should return <Value> x 2 (<ExpectedResult>)" -TestCases $testCases {
        param ($Value, $ExpectedResult)

        $Actual = Invoke-Foo $Value
        $Actual | Should Be $ExpectedResult

[cra...@gmail.com]

Is there a way to pass the current values of $value and $expecteresult to the BeforeEach and AfterEach blocks? 

This doesn't work:

    BeforeEach -TestCases $testCases {

        param ($Value, $Expected)

        Write-Host "Value: $value"
        Write-Host "Expected: $Expected"

    }

[Manuel Henke]

Describe "invoke-foo" {
    $testCases = @(
        @{ Value = 2; ExpectedResult = 4 }
        @{ Value = 4; ExpectedResult = 8 }
        @{ Value = 6; ExpectedResult = 12 }
    )

    It "Should return <Value> x 2 (<ExpectedResult>)" -TestCases $testCases {
        param ($Value, $ExpectedResult)
        $Actual = Invoke-Foo

$Value
        write-verbose -Message ('Actual: {0}' -f $Actual) -Verbose
        $Actual | Should Be $ExpectedResult
    }
}