`$PSScriptRoot` is not populated when running a code block (via F8)

System Details

• Operating system name and version: Windows 10
• VS Code version: 1.10.2
• PowerShell extension version:
• Output from $PSVersionTable:

PS C:\Source\neo4j-quick-demo> $pseditor.EditorServicesVersion

Major  Minor  Build  Revision
-----  -----  -----  --------
0      11     0      0


PS C:\Source\neo4j-quick-demo>
PS C:\Source\neo4j-quick-demo> code --list-extensions --show-versions
PS C:\Source\neo4j-quick-demo>
PS C:\Source\neo4j-quick-demo> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      5.1.14393.953
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.14393.953
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

Issue Description

$PSScriptRoot is not populated when running a code block (via F8)

I am trying load DLLs that are in the same directory as the PowerShell script and use $PSScriptRoot to get the location for them.

When running the code in PowerShell it's fine, but using VSCode, when running the code snippet via F8, the variable is not populated.

Repro

• Open VSCode and create a PowerShell (.ps1) file
• Add the following command Write-Host "$PSScriptRoot\abc"
• Select the newly created line and Press F8 to execute the PowerShell in the integrated terminal

Expected result:
<full working path>\abc

e.g. If the script I was editing was in C:\Source I would expect the result to be C:\Source\abc

Actual result:
\abc

Reproduce the issue by selecting the PowerShell line and pressing F8 to execute it in the integrated terminal, using the documented Windows and VS Code setup. Trace the F8 code-block execution path and verify that $PSScriptRoot resolves to the script directory rather than producing only \abc.