pre-#2038 Write-Output: {Write-Output @() -NoEnumerate}.Invoke() returns empty Collection<PSObject>

[alx9r]

The behavior of Write-Output has been incorrect since #2038 (see #5955, #5122, #6451, etc.). I'd like for its correct behavior to be restored. It seems like restoring Write-Output to its pre-#2038 implementation wouldn't be entirely sufficient, however. It seems like there's something that changed between version 5.1 and 6.1-preview that affects how the pre-#2038 implementation of Write-Output behave for empty arrays. That is why I'm opening this issue.

For this repro I've implemented Write-Output2 as a stand-in for pre-#2038 Write-Output (see #6451(comment)) . I believe (and it is my intention) that this implementation of Write-Output2 matches the pre-#2038 implementation of Write-Output.

Steps to reproduce

Add-Type '
    using System.Management.Automation;

    [Cmdlet(VerbsCommunications.Write, "Output2")]
    public class WriteOutput2Command : PSCmdlet
    {
        private PSObject[] _inputObjects = null;

        [Parameter(Position = 0, Mandatory = true, ValueFromPipeline = true, ValueFromRemainingArguments = true)]
        [AllowNull]
        [AllowEmptyCollection]
        public PSObject[] InputObject
        {
            get { return _inputObjects; }
            set { _inputObjects = value; }
        }

        [Parameter()]
        public SwitchParameter NoEnumerate
        {
            get;
            set;
        }

        protected override void ProcessRecord()
        {
            if (null == _inputObjects)
            {
                WriteObject(_inputObjects);
                return;
            }

            bool enumerate = true;
            if (NoEnumerate.IsPresent)
            {
                enumerate = false;
            }
            foreach (PSObject inputObject in _inputObjects)
            {
                WriteObject(inputObject, enumerate);
            }
        }//processrecord
    }' -PassThru | % Assembly | Import-Module

$c = {Write-Output2 @() -NoEnumerate}.Invoke()
$c.Count

Expected behavior

I expected the Collection<PSObject> returned by .Invoke() to contain a reference to the empty array passed to Write-Output2. I expected that Write-Output -NoEnumerate should be transparent to the object passed to it. Such behavior would match the behavior in version 5.1.

1

Actual behavior

The Collection<PSObject> does not contain anything.

0

Environment data

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      6.1.0-preview.688
PSEdition                      Core
GitCommitId                    v6.1.0-preview.688
OS                             Microsoft Windows 6.3.9600
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

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This issue has not had any activity in 6 months, if this is a bug please try to reproduce on the latest version of PowerShell and reopen a new issue and reference this issue if this is still a blocker for you.

[microsoft-github-policy-service]

This issue has not had any activity in 6 months, if this is a bug please try to reproduce on the latest version of PowerShell and reopen a new issue and reference this issue if this is still a blocker for you.

[microsoft-github-policy-service]

This issue has not had any activity in 6 months, if this is a bug please try to reproduce on the latest version of PowerShell and reopen a new issue and reference this issue if this is still a blocker for you.

[microsoft-github-policy-service]

This issue has been marked as "No Activity" as there has been no activity for 6 months. It has been closed for housekeeping purposes.