#Invoke pester code#

I have tried to include relevant parts of the code in my blog, but readability isn’t as good as I would like it to be.

Checking code coverage, modifying code / tests, rerunning tests and checking code coverage.

Analyzing the results, fixing code and re-running tests until all tests pass.

Actually writing the PowerShell / Pester code for the tests you came up with.

To be honest I didn’t expect many advantages of using Pester for this specific script.Īctually getting started with Pester consisted of the following steps that will be described in more detail: Basically it would take the input ‘192.168.1.1/24’ split it at the forward slash ( / ) and then use a switch statement to translate the CIDR notation (by example 24) to the subnet mask notation (by example 255.255.255.0).

The example I decided to start was a simple script I wrote in the past for a colleague to translate network addresses in the IP CIDR format to the IP subnet mask format. Instead of continuing to read the book, I decided to simply start using Pester with a simple real-life example and then build upon that. It did provide me with the basics I needed to get started though. I started reading the first couple of chapters, but didn’t finish it yet. If you want to know more about it, check Microsoft’s article ‘Building a Continuous Integration and Continuous Deployment pipeline with DSC’.įirst, I started reading some articles about Pester, then I purchased ‘The Pester Book’ by Adam Bertram. But that’s beyond my knowledge and this post. If you want to, you can use Pester as part of your Continuous Integration and Continuous Deployment (CI/CD) pipeline. Keep in mind however that if you change your code, you might also need to change and/or add tests. A more common reason is when you change (parts of) your code that you can easily verify if your changes did not break anything.

#Invoke pester windows#

Reasons to re-run these tests could be if you run the code under other circumstances like by example with PowerShell Core instead of Windows PowerShell or on Windows Server 2019 instead of Windows Server 2012 R2. By example if you’ve created an Operating System deployment or configured DSC, you can check if the configuration has been applied (correctly) or not.Īnother advantage of having Pester tests is that you can easily re-run tests without spending much time.

Instead of using it to test your code, you can also use it to test if a configuration is the way it should be/you want it to be. This way you can verify if your code works as expected. Then the result of the test either passes or fails. So basically you use it to run scripts/functions/code with a specific input and tell Pester what the expected output should be. “Pester provides a framework for running Unit Tests to execute and validate PowerShell commands”. I have been playing around a bit already with parallelization and Github and the next thing on my list was Pester.įor those that do not know it, the Pester Wiki describes Pester as follows: These include, but are not limited to parallelization, GitHub, DSC, PowerShell Core, JEA, Plaster, DBAtools and DBAchecks. $RemoteHost = Read-Host 'Enter the computer to connect' $userprincipalname = ' $( ( $ env : USERNAME ) $creds = ( Get-Credential -Message 'Enter the credentials' -UserName $userprincipalname ) Enter-PSSession -ComputerName $RemoteHost -Credential $creds Import-Module Pester -MinimumVersion 4.4.On my list I have a couple of PowerShell related subjects I want/need to learn more about.