Jakub Jareš

Make your code faster with Profiler

Jakub Jareš
4 Min To Read
04 May, 2021

Making PowerShell code faster has always been a difficult task. There are few DOs and DON’Ts of writing fast PowerShell code, but until now there was not a good way to measure what is actually happening.

Jakub Jareš
8 Min To Read
03 Dec, 2015
- Dev ops
- Pester

This article is a part of a larger series on Pester. Last time, we looked at how assertions work in theory, and how they are implemented in Pester.

Jakub Jareš
8 Min To Read
02 Dec, 2015
- Dev ops
- Pester

This article is a part of a larger series on Pester. Last time we looked at the theory of assertions and what mechanisms they use to fail our tests.

Jakub Jareš
9 Min To Read
01 Dec, 2015
- Pester
- Dev ops

This article is a part of a larger series on Pester. I always found the word framework intimidating. It’s probably because my first encounter with the word was in .

Jakub Jareš
2 Min To Read
04 Jun, 2015
- Pester

Pester has a great feature called TestCases. This feature enables you to easily call the same test code multiple times, but with different data.

Jakub Jareš
10 Min To Read
02 Jun, 2015
- How to

Today I will show how to defensively script against enums and how to test invalid enum values. What is an enum?

Jakub Jareš
2 Min To Read
13 Jan, 2015
- Pester

Authoring Pester tests is easy as it is, but if you are lucky enough to own a copy of ISESteroids 2 it now became even easier.

Jakub Jareš
11 Min To Read
30 Sep, 2014
- Pester
- Dev ops

In this part of Pester basics series, I will cover the most powerful tool from the whole framework, the Mock function.

Jakub Jareš
10 Min To Read
27 Mar, 2014
- Dev ops
- Pester

This is part two of Pester series of articles. In this article you will learn about the Context keyword, how to use all the assertions available in Pester and a bit about best practices.

Jakub Jareš
4 Min To Read
24 Mar, 2014
- How to

While we worked on Windows 8.1 deployment, we were required to make multiple keyboard layouts available on the Windows logon screen.

Jakub Jareš
9 Min To Read
12 Mar, 2014
- Pester
- Dev ops

Some time ago I stumbled upon the Pester framework that promised I would be able to test my scripts. This seemed to be super-useful for my day-to-day scripting, but unfortunately the learning curve was a bit steeper than I thought it would be.

Jakub Jareš
3 Min To Read
18 Feb, 2014
- Tips and tricks

Note: This tip requires PowerShell 2.0 or above. Comparing two System.DateTime objects in PowerShell is really easy. All you need to do is:

Jakub Jareš
2 Min To Read
18 Dec, 2013
- Tips and tricks

Note: This tip requires PowerShell 2.0 or above. In this very helpful tip, Bartek shown us how to create a custom object using the New-Module cmdlet and how to constrain the data the object can hold.

Jakub Jareš
2 Min To Read
18 Jul, 2013
- Tips and tricks

Note: This tip requires PowerShell 2.0 or above. This week on a PowerShell forum, I stumbled upon user request to turn off his PC’s display on demand.

Jakub Jareš
2 Min To Read
08 Jul, 2013
- Tips and tricks

In a perfect world all date and time data available are represented by System.DateTime objects. In the real world we are usually not that lucky.

Jakub Jareš
1 Min To Read
04 Feb, 2013
- Tips and tricks

They say that PowerShell is the ultimate tool that provides almost infinite number of possible applications. So I wondered: What should I do to actually express infinity in PowerShell?

Jakub Jareš
6 Min To Read
04 Feb, 2013
- How to

Creating PowerShell custom objects is a common task that some find hard to do right. In this article I’ll show a sample code that has some of the common flaws.

Jakub Jareš
1 Min To Read
01 Feb, 2013
- Tips and tricks

Modifying a file always brings a risk of corrupting it; making a backup copy whenever possible is one of the file manipulation best-practices.

Jakub Jareš
2 Min To Read
21 Jan, 2013
- Tips and tricks

On one of the PowerShell forums someone asked for help with getting the 15 most used words in a webpage. The core of the answer to that question is amazingly clever use of a hash table.

Jakub Jareš
2 Min To Read
14 Jan, 2013
- Tips and tricks

Note: This tip requires PowerShell 3.0 or above. The PowerShell ISE 3.0 brought a lot of new features. One of them is the ability to hide parts of the code by folding them.

Jakub Jareš
3 Min To Read
02 Jan, 2013
- How to

Every now and then I find myself facing task I am not sure how to solve using without using native commands.

Jakub Jareš
1 Min To Read
06 Dec, 2012
- Tips and tricks

Going through folders, you sometimes find yourself in some strangely named ones you are sure you’ll have to revisit again. To avoid searching for the folders after some digging around, use the pushd (Push-Location) command to save your current location to stack.

Jakub Jareš
2 Min To Read
12 Nov, 2012
- Brainteaser
- Tips and tricks

The -replace operator takes a regular expression (regex) replacement rule as input and replaces every match with the replacement string. The operator itself is used as shown in the following schema: <input string> -replace <replacement rule>,<replacement string>

Jakub Jareš
1 Min To Read
17 Oct, 2012
- Tips and tricks

Sometimes you need to wait for an executable to finish its job. The typical case is a Setup.exe, but this behavior is also ideal candidate for cleaning up temporary files after an application has been closed.

Jakub Jareš
1 Min To Read
15 Oct, 2012
- Tips and tricks

Have you ever wondered how often is your station rebooted? Let’s ask the Windows Event Log and get time of last five reboots.

Jakub Jareš

Make your code faster with Profiler

Pester Explained: Describe, Context, and It Blocks

Pester Explained: Should

Pester Explained: Introduction and Assertions

Pester: Triangulation and reusing test cases

Coding defensively against enums

Boost your productivity with Pester snippets

Pester Mock and TestDrive

Testing your PowerShell scripts with Pester: Assertions and more

Set keyboard layouts available on logon screen in Windows 8.1

Get started with Pester (PowerShell unit testing framework)

#PSTip Comparing DateTime with a given precision

#PSTip Overriding the ToString() Method

#PSTip How to switch off display with PowerShell

#PSTip Converting a String to a System.DateTime object

#PSTip To infinity and beyond!

Creating PowerShell custom objects

#PSTip One way to change a file extension

#PSTip Count occurrences of a word using a hash table

#PSTip Use custom regions to fold code in PowerShell ISE 3.0

Calling native commands from PowerShell

#PSTip Use Push-Location to save your current location

#PSTip A difference between the –replace operator and String.Replace method

#PSTip Wait for executable to finish

#PSTip Get your reboot history