Software Testing - create a PowerShell script part 3

Hi all,

Welcome to another episode of the Software Testing series. Today, we will continue our work with PowerShell script that allows us to automatically create a new Windows user. If You miss that - check the first episode of the series: https://read.cash/@Otek/software-testing-create-a-powershell-script-part-1-bb9d9df4 .

Last time when We finished our script look s that way:

<#
.DESCRIPTION
    Create a new Windows User.
.EXAMPLE
    C:\PS> Set-ExecutionPolicy remotesigned
    C:\PS> Import-Module createNewUser.ps1
    C:\PS> CreateUser -Name TestUserScript1
#>

So let's go further with that, :) Our next lines will look like in the code block above:

function CreateUser {
    [CmdletBinding(SupportsShouldProcess=$true)]
    param(
        # Specifies a user name
        [Parameter(Mandatory=$true,
                   Position=0,
                   ParameterSetName="Name",
                   HelpMessage="Name of new User")]
        [Alias("UserName")]
        [ValidateNotNullOrEmpty()]
        [String]
        $Name
    )
}

Like always, we will discuss it line by line.

function CreateUser {

First-line start our function. Each script can have multiple of them. Our function name is: CreateUser (it is a good practice to the naming of the function that will clearly show what that function will do). Whole lines between {} will belong to CreateUser function.

Next line:

[CmdletBinding(SupportsShouldProcess=$true)]

is our function attribute. The CmdletBinding attribute is an attribute of functions that makes them operate like compiled cmdlets written in C#. It provides access to the features of cmdlets - so in a short words it allows us to create more complicated scripts and use a cmdlts functions which are very useful.

 param(

Here we specify what parameters our function will have and have they will work.

# Specifies a user name

Here we just create a comment to someone who will use our script later - it just informs what parameter we specify above - it can be extremely useful when our script will have more of them.

[Parameter(Mandatory=$true,

Next line we will start set attributes of our function Parameter. Each of them are separated by ",". The first one is Mandatory=$true here we decide if our parameter will be mandatory (values that we can set are true and false) - in our case it should be mandatory - cause script needs to know with what name he should create a new user.

Position=0, that one is very useful when the function will have multiple parameters. If the user gives them e.g. CreateUser 'firstParameter' 'secondParameter' position 0 means that script will take 'firstParameter' here.

ParameterSetName="Name", - here we give our parameter name :)

HelpMessage="Name of new User")] - if script user will use help function, information we set here will display to him :) It is important to not forget to end the whole Parameter section with "]" character.

[Alias("UserName")]

Here, we set an alias for our parameter. It is an alternate name or nickname for a cmdlet or for a command element, such as a function, script, file, or executable file. You can use the alias instead of the command name in any PowerShell commands.

[ValidateNotNullOrEmpty()]

The ValidateNotNullOrEmpty attribute specifies that the parameter value can't be $null or be empty as well. If that happened PowerShell generates an error.

[String]

That is very important part - here we decide what format or more what type parameter should be. It can be a numeric value, text, table etc. In programming convention String value will treat all parameters provide by user as a text.

$Name

Here is just define of how our parameter will be called in our script.

Ok, let's sum that all up.

Today we created the function CreateUser. It got one mandatory parameter which name is "Name" and it is a text (String) type.

Next time we will use that parameter in our script and create a new user based on it :)