Keeping Track of PowerShell Functions in Script Modules when Dot-Sourcing PS1 Files

I’m picking up where I left off in a previous blog article “Write Dynamic Unit Tests for your PowerShell Code with Pester“. I’m using the dynamic Test-MrFunctionsToExport Pester test that I wrote about in that previous blog article. Currently, the test is failing for my MrToolkit module that’s part of my PowerShell repository on GitHub:


Based on the previous results, I can easily determine that more functions exist in the module folder than are specified in the FunctionsToExport section of the module manifest. That may sound like a simple fix but once you have tons of PS1 files in the module folder and a similar number specified in the manifest, it becomes difficult to know what’s missing so I’ve written a tool to generate a list of the function names:

For those of you who didn’t read the previous blog article that I referenced, I’ve moved to the model of placing each of my functions into a separate PS1 file and the file base name is the same as the function name. Each PS1 file is dot-sourced in the PSM1 file when the module is imported and a list of the function names must exist in the FunctionsToExport section of the module manifest (or exported via Export-ModuleMember in the PSM1 file).

I’ll use this tool to generate a list of function names. If nothing is specified in the FormatsToProcess or TypesToProcess section of the module manifest, it can be updated programmatically using the Update-ModuleManifest cmdlet. Unfortunately a known error is generated as shown in the following example if either or both of these are specified:


Update-ModuleManifest : Cannot update the manifest file ‘.\GitHub\PowerShell\MrToolkit\MrToolkit.psd1’ because the
manifest is not valid. Verify that the manifest file is valid, and then try again.’The member ‘FormatsToProcess’ in
the module manifest is not valid: Cannot find path
‘C:\Users\mikefrobbins\AppData\Local\Temp\1707008812\GitHub\PowerShell\MrToolkit\MrToolkit.ps1xml’ because it does not
exist.. Verify that a valid value is specified for this field in the
‘C:\Users\mikefrobbins\AppData\Local\Temp\1707008812\NewManifest.psd1′ file.’
At line:1 char:1
+ Update-ModuleManifest -Path .\GitHub\PowerShell\MrToolkit\MrToolkit.p …
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (System.Argument…rd errorRecord):ArgumentException) [Update-ModuleMan
ifest], ArgumentException
+ FullyQualifiedErrorId : UpdateManifestFileFail,Update-ModuleManifest

The sub-command used in the previous example creates a simple list of the function names:


Luckily, I’ve written the Get-MrFunctionToExport function so it generates a list in the proper format that can be pasted into the module manifest if you happen to run into a scenario such as this one where Update-ModuleManifest can’t be used.


The easiest way to copy the results of the previous command is to simply pipe it to clip.exe:


After pasting the results into the FunctionsToExport section of the module’s manifest (PSD1 file), the Pester test runs without issue:


Keeping track of functions and making sure they’re all specified in the FunctionsToExport section of the module manifest can be a annoying to maintain but it’s a necessary evil if you want module auto-loading to work properly when placing the functions from your modules in separate PS1 files.

Why not make your life a little easier by creating tools to make building other tools easier?


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