Become a Patron of the PSKoans project!
Inspired by Chris Marinos's fantastic F# koans, the goal of the PowerShell koans is to teach you PowerShell by presenting you with a set of questions. Each kōan (each question) is represented by a failing Pester test. Your goal is to make those tests pass by filling out the correct answer, or writing the correct code. The koans start very simple to get you familiar with the basic concepts and progress towards more difficult. Teaching you multiple beginner, intermediate and advanced aspects of PowerShell in the process.
To get started please navigate to prerequisites and getting started.
- Windows PowerShell version 5.1 / PowerShell 6+
- Pester
To install the latest version of Pester, use the appropriate command for your version of PowerShell:
# PS 5.1 (upgrade to latest Pester)
Install-Module Pester -Force -SkipPublisherCheck -Scope CurrentUser
# PS 6.0+ (Install Pester under current user)
Install-Module Pester -Scope CurrentUser
Install-Module PSKoans -Scope CurrentUser
git clone
the repository into your desired directory, or download the repository as a .zip file and extract into a directory of your choice.- From a normal powershell session run
Get-ChildItem -Recurse | Unblock-File
in that directory to remove the "downloaded from internet" flag that blocks them from running. - Check
Get-ExecutionPolicy
: if it says 'Restricted' or 'Undefined', you need to also runSet-ExecutionPolicy RemoteSigned
in order to allow the scripts to run. - Add the repository folder to
$env:PSModulePath
so that PowerShell can see it.- From the repository main folder, run:
$env:PSModulePath = "$(Get-Location)$([IO.Path]::PathSeparator)${env:PSModulePath}"
- From the repository main folder, run:
You will be presented with a page describing your goal:
Welcome, seeker of enlightenment.
Please wait a moment while we examine your karma...
Describing 'Equality' has damaged your karma.
You have not yet reached enlightenment.
The answers you seek...
Expected strings to be the same, but they were different.
Expected length: 5
Actual length: 2
Strings differ at index 0.
Expected: 'True!'
But was: '__'
-----------^
Please meditate on the following code:
[It] expects you to fill in values
at <ScriptBlock>, C:\Users\Joel\PSKoans\Foundations\AboutAssertions.Koans.ps1: line 32
32: '__' | Should -Be 'True!'
▌ Mountains are merely mountains.
You examine the path beneath your feet...
[AboutAssertions]: [――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――] 0/4
[Total]: [―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――] 1/279
Type 'Measure-Karma -Meditate' when you are ready to begin your meditations.
Inspect the red messages carefully, most importantly the last one.
The error message contains path to the file that you need to edit in order to progress forward.
In this case, you'll need to examine Foundations\AboutAssertions.Koans.ps1
.
Navigate to Foundations\AboutAssertions.Koans.ps1
. Near the top you'll see:
It 'is a simple comparison' {
# Some truths are absolute.
'__' | Should -Be 'True!'
}
The __
represents a blank for you to fill, and | Should -Be 'True!'
shows the expected result.
To pass this koan you need to replace __
with True!
, like this: 'True!' | Should -Be 'True!'
.
You passed your first koan!
You'll notice that your overall progress updated to 1/279
and you are presented with the next challenge.
Welcome, seeker of enlightenment.
Please wait a moment while we examine your karma...
Describing 'Equality' has damaged your karma.
You have not yet reached enlightenment.
The answers you seek...
Expected 3, but got .
Please meditate on the following code:
[It] expects you to fill in values
at <ScriptBlock>, C:\Users\Joel\PSKoans\Foundations\AboutAssertions.Koans.ps1: line 32
32: __ | Should -Be (1 + 2)
▌ The most important thing is to find out what is the most important thing.
You examine the path beneath your feet...
[AboutAssertions]: [▰▰▰▰▰▰▰▰▰▰▰▰▰▰▰―――――――――――――――――――――――――――――――――――――――――――――] 1/4
[Total]: [―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――] 1/279
Type 'Measure-Karma -Meditate' when you are ready to begin your meditations.
You are on your own from here, but the progression should be fairly smooth. If you need help, you can always ask around in the PowerShell communities:
Good luck!
If you would like to contribute to PSKoans, please check out the Contributing document.