Preview.4 - Remove-Module PSReadLine stops Tab Completion in non-Windows systems

[MaximoTrinidad]

Removing PSReadLine doesn't impact the Tab-Completion in both Windows PowerShell and PowerShell Core.

But tab-completion stops working in non-Windows Systems!

Steps to reproduce

Remove the PSReadLine module and use the change directory command tab to complete folder name

Remove-Module -Name PSReadLine
cd Docu (press-tab)
Get-Mod(tab) -List(tab)

Expected behavior

To auto-complete the line.

Actual behavior

Doing Tab does nothing!

Environment data

WSL - Ubuntu

PS /home/maxt> $PSversiontable

Name                           Value
----                           -----
PSVersion                      6.1.0-preview.4
PSEdition                      Core
GitCommitId                    6.1.0-preview.4
OS                             Linux 4.4.0-17741-Microsoft #1000-Microsoft Tue Aug 14 14:30:00 PST 2018
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Ubuntu 17.04

PS /home/maxt> $PSversiontable

Name                           Value
----                           -----
PSVersion                      6.1.0-preview.4
PSEdition                      Core
GitCommitId                    6.1.0-preview.4
OS                             Linux 4.15.0-32-generic #35-Ubuntu SMP Fri Aug 10 17:58:07 UTC 2018
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

CentOS 7

PS /home/maxt> $PSversiontable

Name                           Value
----                           -----
PSVersion                      6.1.0-preview.4
PSEdition                      Core
GitCommitId                    6.1.0-preview.4
OS                             Linux 3.10.0-862.11.6.el7.x86_64 #1 SMP Tue Aug 14 21:49:04 UTC 2018
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

[thezim]

Repros on macOS as well on rc1.

PS /Users/thezim> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      6.1.0-rc.1
PSEdition                      Core
GitCommitId                    6.1.0-rc.1
OS                             Darwin 17.7.0 Darwin Kernel Version 17.7.0: Thu Jun 21 22:53:14 PDT 2018; root:xnu-4570.71.2~1/RE...
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

[lzybkr]

This is by design and related to how the system level command line editing is implemented.

On Windows systems, there is a (mostly simple) hook to provide a callback when hitting Tab and PowerShell used that hook from the very beginning.

On non-Windows systems, there is no such hook. If you want custom behavior when typing any key like Tab, you must fully implement command line editing, which is exactly what PSReadLine does.

It was an intentional decision to not implement another command line editor for non-Windows systems. Actually, there was a basic one before PSReadLine was ported, but it never supported tab completion, and when it came time to consider implementing tab completion, porting PSReadLine was the more pragmatic option.

[MaximoTrinidad]

I understand!

Thanks,
:)