If a script block is passed in a script function and invoked there by the dot operator then it operates in the current scope.
If a script block is passed in a module function and invoked there by the dot operator then it does not operate in the current scope. Where it operates depends on other factors.
Scripts
- Script1.ps1 defines the function Invoke-ScriptBlockParameter which is used in the module and script.
- Module1.psm1 dot-sources Script1.ps1 and exports Invoke-ScriptBlockParameter for testing.
- Test-Module1.ps1 imports Module1.psm1 and calls Invoke-ScriptBlockParameter, the results are strange.
- Test-Script1.ps1 dot-sources Script1.ps1 and calls Invoke-ScriptBlockParameter, the result is expected.
- .test.ps1 tests Test-Script1.ps1 and two ways of invoking Test-Module1.ps1 with two different results.
A workaround was suggested by Tom Maddock at Microsoft Connect. A script block
$ScriptBlock passed in a module function may be invoked as
. $MyInvocation.MyCommand.Module $ScriptBlock
In this case $ScriptBlock operates in the current scope.
Scripts
- Workaround/Module2.psm1 exports a function which invokes a script block using the workaround.
- Workaround/Test-Module2.ps1 imports the module and passes a script block in the function.
- Workaround/.test.ps1 tests the workaround.
- Stack Overflow Strange behaviour with PowerShell scriptblock variable scope and modules
- Microsoft Connect 560504