Describe 'Calculator' {
    BeforeAll {
        # Easy breezy tests
        $test1 = Calculator -n1 4 -n2 5 -s '+'
        $test2 = Calculator -n1 12 -n2 5 -s '-'
        $test3 = Calculator -n1 20 -n2 3 -s '*'
        $test4 = { Calculator "Write-Host" "Hello World" }
    }
    Context 'FixedTests' {
        It "Should pass" {
            $test1 | Should -Be 9
        }
        It "Should pass" {
            $test2 | Should -Be 7
        }
        It "Should pass" {
            $test3 | Should -Be 60
        }
        It "Should throw" {
            { $test4.Invoke() } | Should -Throw
        }
    }

    Context 'RandomTests' {
        function ans($n1, $s, $n2 ) {
            Invoke-Expression ("$n1  $s  $n2")
        }
        0..100 | ForEach-Object {
            $s = '+', '-', '*' | Get-Random
            $n1 = Get-Random -Maximum 1000
            $n2 = Get-Random -Maximum 1000
            $ans = ans($n1, $s, $n2)
            It "Should pass" {
                Calculator $n1 $s $n2 | Should -be $ans
            }
        }
    }
}