#Pester mock code

However, if you’re in a pinch there is an alternative. You’ll want to search around for an introduction to classes in PowerShell. If you’re not familiar with classes at all, …I’m impressed that you read this far. Get-TestDriveItem In InModuleScope Invoke-Mock Invoke-Pester. If you’re familiar with classes but aren’t familiar with them in PowerShell, checkout the post PowerShell v5 Classes & Concepts by Michael Willis. Pester is the framework for testing your powershell scripts, functions and modules. With mocking in Pester, you can mimic the behavior of commands referenced by the unit you are testing, which ensures that you only test your code, not the referenced commands. Unit tests are used to verify the behavior of a certain part of your PowerShell code. I tend to define mock-classes one scope up from where I’ll use them. Adam Bertram Tue, Jul 26 2016Mon, powershell 1. Unfortunately, creating custom objects within the Mock is not ideal when dealing with complex Mock objects with nested properties.

#Pester mock code

We did this because the context and it child-blocks have visibility into the parent describe block. With Pester’s Mock function, we can isolate our code from this outside (hostile ) world by faking commands and make them return whatever we want, even a custom object. Lastly, the classes were defined in a describe block. We do this because you can’t create a variable of type fake_smo_connnection_context until type fake_smo_connnection_context has been defined. Since fake_smo_server contains fake_smo_connnection_context we’re declaring fake_smo_connnection_context before fake_smo_server. Pester also contains a powerful set of Mocking Functions that allow tests to mimic and mock the functionality of any command inside of a piece of powershell.

We’re only creating the parts of the server object needed to unit test this function. Using these mocking functions can allow you to. We’re not creating a complete facsimile of the type we want to mimic. Pester provides a set of Mocking functions making it easy to fake dependencies and also to verify behavior. fake_smo_connnection_context mocks the ConnectionContext type. It’s just the way the normal Powershell functions work. This is not a Pester issue and it’s not a Powershell issue either. fake_smo_server, a class to mock the server objectįake_smo_connnection_context has single method named Connect() that does nothing and a single property ConnectTimeout. Running the test now results in the expected output: Describing Mocking ErrorAction Example + Get-VM Throws 177ms Tests completed in 177ms Passed: 1 Failed: 0 Skipped: 0 Pending: 0.fake_smo_connnection_context, a class to mock the server’s ConnectionContext object.To illustrate the fix we’ll use the following example: function do-thing | Should -Throw Mocking is used to reduce the scope of a set of tests. As result, the method is executed when you run your test script. The ability to mock commands is a prominent feature of Pester. NET objects, and you can’t mock those method calls. Unfortunately, several of the functions call methods of. You want to use Pester, a unit testing framework for PowerShell, to create unit tests for those functions. You have written several functions in a PowerShell script or module.