PESTER CODE COVERAGE INSTALL
PESTER CODE COVERAGE WINDOWS

If you are creating a module that you want to be usable for anyone running PowerShell, you need to run your tests on all platforms available, as well as Windows PowerShell. However, one flaw here is that we are now running this on PowerShell 7 only, Windows only. Turns out, this works just as you expect it to. I just like the false sense of security by defining -Force 😅 Some of the parameters and switches are probably unnecessary, as the container you get served is completely clean. Run Pester on the directory containing the tests files, in my case it is called tests.

PESTER CODE COVERAGE INSTALL

Install Pester, make sure nothing stops it from doing so by using -Confirm:$false and -force.

Run a couple of cmdlets inline in PowerShell 7, as defined by the shell selection at the end.

Checks-out the repository to our workspace, so we can interact with our code.

Runs a job called test-pwsh on the latest available Windows image.

Runs on every git push to a branch called main (change this to suite your needs).

Just to break it down, here we have an action that: Install-Module -Name Pester -RequiredVersion 5.0.4 -Confirm:$false -Force

go back to doing proper engineering and empower yourself with coverage to build something your proud of.Ĭode coverage can be an incredibly powerful tool to improve the quality of your code as long as you don’t blindly optimize for maximum coverage.Run: | Set-PSRepository psgallery -InstallationPolicy trusted.

So the next time your boss asks you to have 100% code coverage, you know what to do: Or how about automatically adding a coverage report to every pull request? This is something I do for all my open source projects. Why not use it to identify parts of your app that should get some extra testing love? The real value is in the evolution of code coverage over time.Īssume the team is proficient in writing high quality tests and has the ambition to have everything well tested, then code coverage shouldn’t decrease right? Wasted effort with hardly any value in return.

The resulting tests usually also tend to be so complex that they will end up being a maintenance burden. Trying to test complex things doesn’t just take way to much effort. Think about UI animations, communication between Threads, operations on filesystem,… While everything can be tested, not everything is easy to test! This is because the tool can too easily be fooled and 100% coverage is in that regard meaningless.Įven if coverage wouldn’t be flawed, it still would be a mistake to try and get 100% coverage. Hopefully it is clear now that you should never use code coverage as a goal or KPI (key performance indicator). We would need to add multiple tests (covering the same line of code) to guarantee that. Public class Calculator Īll above tests would still pass, code coverage would be 100% but your code doesn’t functionally do what it should. Let’s narrow down the scope and look at one single very focussed class e.g. (Note that this is typically something you address with integration tests.) Class coverage Well obviously no! Because even if all your classes have 100% coverage, that still doesn’t mean they will correctly interact with each other.įor instance your JSON parser could get an unexpected response back from the web server.

If your app has 100% code coverage, are you then sure everything will work as expected? (i.e. Take a step back and try to answer the following question: This post will deep dive in what code coverage actually means, detail why you should never set coverage goals and help you get the most value out of this concept. Besides some code being hard to test, the concept of coverage is actually fundamentally limited. While you may be tempted to strive for 100% code coverage, that would be a horrible idea.

Pester code coverage