. $PSScriptRoot\..\..\Load-PesterModules.ps1
$here = Split-Path -Parent $MyInvocation.MyCommand.Path
$sut = (Split-Path -Leaf $MyInvocation.MyCommand.Path) -replace '\.tests\.', '.'
$functionPath = Join-Path -Path $here -ChildPath $sut
Write-Host "Overriding SUT: $functionPath"
Import-Module $functionPath -Force
$moduleForMock = ""

#region Test-IsNull

Describe "Legacy Test-IsNull" {

    Mock -ModuleName $moduleForMock Write-Warning -MockWith {}
    Context "When Value A is Null" {

        It "Returns Value B" {

            Test-IsNull $null "ValueB" | Should -Be "ValueB"
        }
    }

    Context "When Value A is an Empty String" {

        It "Returns Value B" {

            Test-IsNull "" "ValueB" | Should -Be "ValueB"
        }
    }

    Context "When Value A is Not Null" {

        It "Returns Value A" {

            Test-IsNull "ValueA" "ValueB" | Should -Be "ValueA"
        }
    }

    Context "When Value A is `$false" {

        It "Returns ValueB" {

            Test-IsNull $false "ValueB" | Should -Be "ValueB"
        }
    }

    Context "When Called Without Strict Parameter" {
        It "Warns The User They're Using An Old Version" {
            Test-IsNull "ValueA" "ValueB"
            Assert-MockCalled -CommandName Write-Warning -Times 1 -Exactly -Scope It -ModuleName $moduleForMock -ParameterFilter { $Message -match "You are using the old version of this function" }
        }
    }
}

Describe "Strict Test-IsNull" {

    Context "When Value A is Null" {

        It "Returns Value B" {

            Test-IsNull $null "ValueB" -Strict | Should -Be "ValueB"
        }
    }

    Context "When Value A is an Empty String" {

        It "Returns an Empty String" {

            Test-IsNull "" "ValueB" -Strict | Should -Be ""
        }
    }

    Context "When Value A is Not Null" {

        It "Returns Value A" {

            Test-IsNull "ValueA" "ValueB" -Strict | Should -Be "ValueA"
        }
    }

    Context "When Value A is `$false" {

        It "Returns Value A `$false" {

            Test-IsNull $false "ValueB" -Strict | Should -Be $false
        }
    }
}

#endregion Test-IsNull