Exposing PowerShell Module Scope

I opted for the double underscore so I wouldn't mistake it for the pipelined variable $_

            May 16, 2024

        Exposing PowerShell Module Scope

            In the previous article, I demonstrated how to take advantage of the module scope. This is what allows you to have functions and variables available to commands in your module, but not exposed to the user. I take advantage of this in almost all of my PowerShell modules. To make it clear in my code, I make sure my internal functions use a non-standard name. I haven't worried too much about the variable name. I typically call it what I need it to be. But, I can see a benefit in adding a prefix or some indication to the variable name to make it clear that it is an internal variable.

[version]$__Version = '1.0.0'

> *I opted for the double underscore so I wouldn't mistake it for the pipelined variable $_*

Then, in my functions, I can reference this variable.

Write-Verbose "Running module version $__version"

If I see a variable in my session with a double underscore, I know it is an internal variable from a module and I've made a mistake somewhere.

Regardless, it wouldn't hurt to add documentation in your commands to make it clear you are referencing an internal variable, including where it is defined.

There is also a technique you can use to expose the internal members of your module from your PowerShell session. That's what I want to show you today.

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In the previous article, I demonstrated how to take advantage of the module scope. This is what allows you to have functions and variables available to commands in your module, but not exposed to the user. I take advantage of this in almost all of my PowerShell modules. To make it clear in my code, I make sure my internal functions use a non-standard name. I haven't worried too much about the variable name. I typically call it what I need it to be. But, I can see a benefit in adding a prefix or some indication to the variable name to make it clear that it is an internal variable.
[version]$__Version = '1.0.0'

I opted for the double underscore so I wouldn't mistake it for the pipelined variable $_

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Exposing PowerShell Module Scope