Index Pester

function MyFunction {
    [CmdletBinding()]
    param (
        [System.String[]]$MyStringParameter = "ThisIsMyString",
        [System.Int32[]]$MyIntParameter = 32,
        [System.Array]$Filter = @()
    )
}

It 'Parameter MyStringParamter should be present and be of type String' {
    Get-Command MyFunction | Should -HaveParameter 'MyStringParameter' -Type [System.String[]]
    }
It 'Parameter MyIntParamter should be present and be of type Int32' {
    Get-Command MyFunction | Should -HaveParameter 'MyIntParameter' -Type [System.Int32[]]
    }
It 'Parameter Filter should be present and be of type Array' {
    Get-Command MyFunction | Should -HaveParameter 'Filter' -Type [System.Array]
    }

It 'Parameter MyStringParamter should have ThisIsMyString by default' {
    Get-Command MyFunction | Should -HaveParameter 'MyStringParameter' -DefaultValue 'ThisIsMyString'
    }
It 'Parameter MyIntParamter should have 32 by default' {
    Get-Command MyFunction | Should -HaveParameter 'MyIntParameter' -DefaultValue 32
    }
It 'Parameter Filtre should be empty by default' {
    Get-Command MyFunction | Should -HaveParameter 'Filter' -DefaultValue '@()'
    }