PowerShell Introduction to Pester Getting Started with Pester
Example
To get started with unit testing PowerShell code using the Pester-module, you need to be familiar with three keywords/commands:
- Describe: Defines a group of tests. All Pester test files needs at least one Describe-block.
- It: Defines an individual test. You can have multiple It-blocks inside a Descripe-block.
- Should: The verify/test command. It is used to define the result that should be considered a successful test.
Sample:
Import-Module Pester
#Sample function to run tests against
function Add-Numbers{
param($a, $b)
return [int]$a + [int]$b
}
#Group of tests
Describe "Validate Add-Numbers" {
#Individual test cases
It "Should add 2 + 2 to equal 4" {
Add-Numbers 2 2 | Should Be 4
}
It "Should handle strings" {
Add-Numbers "2" "2" | Should Be 4
}
It "Should return an integer"{
Add-Numbers 2.3 2 | Should BeOfType Int32
}
}
Output:
Describing Validate Add-Numbers
[+] Should add 2 + 2 to equal 4 33ms
[+] Should handle strings 19ms
[+] Should return an integer 23ms
