Job results (from Receive-Job) are grouped by output type, differently than "normal" (BackgroundJob) jobs

[jazzdelightsme]

Consider the following code which starts a ThreadJob:

$job = Start-ThreadJob -ScriptBlock {

    for( $i = 0 ; $i -lt 100 ; $i++ )
    {
        Write-Output "output $i"
        Write-Host "host output $i"
        Write-Information "info output $i"
        Write-Verbose "verbose output $i"
        Write-Warning "warning output $i"

        Start-Sleep -Seconds 5
    }
}

If I receive results of the job, the output is grouped according to the type of output:

PS C:\Users\me> Receive-Job $job
output 0
output 1
output 2
WARNING: warning output 0
WARNING: warning output 1
WARNING: warning output 2
host output 0
host output 1
host output 2
PS C:\Users\me>

This is in contrast to “normal” jobs—if I switch the call out for Start-Job, the results come in a more expected order:

PS C:\Users\me> Receive-Job $job
output 0
host output 0
WARNING: warning output 0
output 1
host output 1
WARNING: warning output 1
output 2
host output 2
WARNING: warning output 2
PS C:\Users\me>

Expected behavior

I expect the output from Receive-Job of a ThreadJob to come in the same order as from a BackgroundJob.

This is because I expect to be able to use thread jobs as a "drop-in" replacement for background jobs (modulo restrictions imposed due to running in the same process, like of course you wouldn't be able to load different versions of .NET assemblies).

Actual behavior

The output from a ThreadJob is all grouped by output type (all Warnings grouped together, all host output grouped together, etc.).

Environment data

Name                           Value
----                           -----
PSVersion                      7.4.5
PSEdition                      Core
GitCommitId                    7.4.5
OS                             Microsoft Windows 10.0.26290
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

PS C:\Users\me> gmo *thread*

ModuleType Version    PreRelease Name                                ExportedCommands
---------- -------    ---------- ----                                ----------------
Binary     2.1.0                 Microsoft.PowerShell.ThreadJob      Start-ThreadJob

Version

7.4.5 / 2.1.0