I hope you’ve been finding this series helpful. I made an assumption that you know a little bit about Pester. I’m showing you examples of real-world tests, but you might want to review the documentation at https://pester.dev/docs/quick-start.

At the end of the previous article, I had a Pester test file that validated parameters and design decisions. I also wrote enough of the function to pass the test. Since then, I decided to add one more design test. I want the Latitude and Longitude parameters to be positional and everything else to be named.

    Param(
        [Parameter(
            Position = 0,
            Mandatory,
            ValueFromPipelineByPropertyName,
            HelpMessage = "Specify the location's latitude."
        )]
        [double]$Latitude,
        [Parameter(
            Position = 1,
            Mandatory,
            ValueFromPipelineByPropertyName,
            HelpMessage = "Specify the location's longitude."
        )]
        [double]$Longitude,
        [Parameter(
            Mandatory,
            ValueFromPipelineByPropertyName,
            HelpMessage = "Specify the location's time zone like America/Los_Angeles."
        )]
        [string]$TimeZone,
        [Parameter(HelpMessage = "Specify if you want to use metric or imperial measurement units.")]
        [ValidateSet("Metric","Imperial")]
        [string]$Units = "Imperial"
    )

I updated the test file with new test cases.