Pester Code Coverage
Code coverage is a metric used to measure the percentage of code that is executed by your automated tests. Pester has built-in support for code coverage analysis.
Parent Topic: Pester Testing in PowerShell
1. Enabling Code Coverage
To measure code coverage, you use the -CodeCoverage parameter with Invoke-Pester. You pass the path to the script file(s) you want to measure.
Invoke-Pester -Path .\MyFunctions.Tests.ps1 -CodeCoverage .\MyFunctions.ps12. Interpreting the Output
Pester will run your tests and then output a code coverage report.
- Covered %: The percentage of commands in the script that were executed.
- Missed Commands: Specific lines or commands that were not run.
Example output:
Tests completed in 200ms
Tests Passed: 2, Failed: 0, Skipped: 0 NotRun: 0
Code coverage report:
Covered 80.00% of 10 analyzed commands in 1 file.
Missed commands:
MyFunctions.ps1: 153. Improving Coverage
If you have low coverage, look at the "Missed commands" section. It usually points to:
if/elsebranches that weren't tested.catchblocks for error handling that weren't triggered.- Unused functions.
To improve coverage, write new It blocks that specifically target those scenarios (e.g., passing invalid input to trigger an error).
Return to Pester Testing in PowerShell