A Quick Tour

A Quick Tour of PSMock

Assuming you have already downloaded the PSMock module, start off by importing it.

Import-Module PSMock

The next thing you need to do is to enable mocks for your current script. This is done with the Enable-Mock call. Enable-Mock defines the Mock function in your script, so PSMock has a chance to inspect functions in your script's scope. You need to do this once per script.

Enable-Mock | iex

So let's say you have an original function:

function Original { "original" }
Original		# "original"

You can mock it with the Mock command. In this case, we will override all calls to Original:

Mock Original { "mocked" }
Original		# "mocked"

We can also remove the mock:

Remove-Mock Original
Original		# "original"

Sometimes you want different code to execute depending on the parameters. You can use the When parameter to filter the execution:

function Hello { param ([string] $who) "Hello, $who" }
Hello you		# "Hello, you"

Mock Hello { } -when { $who -eq "Bob" }
Hello you		# "Hello, you"
Hello bob		# nothing

Mock Hello { "Good day, $who" }
Hello bob		# nothing
Hello you		# "Good day, you"

Remove-Mock Hello
Hello bob		# "Hello, bob"
Hello you		# "Hello, you"

If you are using mocks for testing, you may want to look at the statistics that PSMock keeps for the mocks:

Mock Hello { } -when { $who -eq "Bob" } -name Bob
Mock Hello { "Good day, $who" }

Hello bob					# nothing
Hello you					# "Good day, you"

(Get-Mock Hello).Count		# 2
(Get-Mock Hello -case Bob).Count		# 1
(Get-Mock Hello -case default).Count	# 1
(Get-Mock Hello -case default).Calls[0].BoundParameters['who']	# "you"

You can also use MockContexts to automatically remove certain sets of mocks. This is very handy for more complicated test scenarios. You can even nest MockContexts.

MockContext {
	Mock Hello { } -when { $who -eq "Bob" } -name Bob
	Hello bob				# nothing
}
Hello bob					# "Hello, bob"