Book Image

Mastering Windows PowerShell Scripting (Second Edition) - Second Edition

By : Brenton J.W. Blawat
Book Image

Mastering Windows PowerShell Scripting (Second Edition) - Second Edition

By: Brenton J.W. Blawat

Overview of this book

PowerShell scripts offer a handy way to automate various chores. Working with these scripts effectively can be a difficult task. This comprehensive guide starts from scratch and covers advanced-level topics to make you a PowerShell expert. The first module, PowerShell Fundamentals, begins with new features, installing PowerShell on Linux, working with parameters and objects, and also how you can work with .NET classes from within PowerShell. In the next module, you’ll see how to efficiently manage large amounts of data and interact with other services using PowerShell. You’ll be able to make the most of PowerShell’s powerful automation feature, where you will have different methods to parse and manipulate data, regular expressions, and WMI. After automation, you will enter the Extending PowerShell module, which covers topics such as asynchronous processing and, creating modules. The final step is to secure your PowerShell, so you will land in the last module, Securing and Debugging PowerShell, which covers PowerShell execution policies, error handling techniques, and testing. By the end of the book, you will be an expert in using the PowerShell language.
Table of Contents (24 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Testing with Pester


The PowerShell module Pester can be used to build unit tests for scripts and functions. Unit tests target the smallest possible unit of code, which, in PowerShell, is likely to be a function or a method in a PowerShell class.

Pester tests are saved in a file named ending with .tests.ps1 and executed using the command Invoke-Pester.Invoke-Pester finds files named *.tests.ps1 under a given path and executes all tests in each.

Describe and Should statements may also be entered in the console when exploring syntax, but this is not the normal method of defining and running tests.

While Pester is included with Windows 10, it is not the latest version. The latest version may be installed from the PSGallery:

Install-Module Pester -Force

Why write tests?

A set of tests can help when:

  • Debugging
  • Refactoring

A set of tests can prevent a bug making it out of a development environment, whether as the result of a change, or because the feature is new.

Refactoring, or restructuring, existing code...