PR Summary

Fixes the using expression builder when encountering a using expression with invalid property. Previously such a property would stop the using builder from working on the remaining using statements while ignoring the error. From this change it will still ignore the error but continue working on the remaining expressions.

PR Context

Fixes: #27340

Currently if a using expression throws an error, like an invalid property, when building the using expression it would stop the using value builder from processing the remaining expressions. With this change it instead still continues to process the remaining expressions while still keeping the invalid one as $null like before.

This fixes this statement:

$var1 = 1
$var2 = 2
$var3 = 3
1 | ForEach-Object -Parallel {
    Write-Host "var1 $using:var1"
    Write-Host "var2 $($using:var2.InvalidProp)"
    Write-Host "var3 $using:var3"
}

var1 1
InvalidOperation: 
Line |
   3 |      Write-Host "var2 $($using:var2.InvalidProp)"
     |                         ~~~~~~~~~~~~~~~~~~~~~~~
     | A Using variable cannot be retrieved. A Using variable can be used only with Invoke-Command, Start-Job, or InlineScript in the script workflow. When it is used with Invoke-Command, the Using variable is valid only if the script block is invoked on a remote computer.
var2 
InvalidOperation: 
Line |
   4 |      Write-Host "var3 $using:var3"
     |      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     | A Using variable cannot be retrieved. A Using variable can be used only with Invoke-Command, Start-Job, or InlineScript in the script workflow. When it is used with Invoke-Command, the Using variable is valid only if the script block is invoked on a remote computer.

With the changes here it now becomes

var1 1
var2 
var3 3

This better reflects how the same statement would work in a normal invocation with the same vars outside of $using:.

$var1 = 1
$var2 = 2
$var3 = 3
& {
    Write-Host "var1 $var1"
    Write-Host "var2 $($var2.InvalidProp)"
    Write-Host "var3 $var3"
}

# var1 1
# var2 
# var3 3

The only exception to this was if the inner scriptblock had enabled strict mode but the existing logic isn't equipped to deal with this as it already ignores errors on the client side. All this PR does is to continue resolving the remaining expressions rather than leaving it as unset.

PR Checklist

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• Breaking changes
  • None
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  • Experimental feature(s) needed
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  • Not Applicable
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  • Documentation needed
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• Testing - New and feature
  • N/A or can only be tested interactively
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  • Make sure you've added a new test if existing tests do not effectively test the code changed