test: improve `parallel/test-setproctitle.js`

[refack]

• Version: master
• Platform: Windows
• Subsystem: test,process

Current implementation skips a part of the test claiming 'Windows does not have "ps" utility' which is not strickly true — Windows has tasklist and PowerShell has ps aliasing Get-Proccess.

The rest of the test should be implemented for Windows.

[richardlau]

I looked at this briefly when the skip was added (#11416 (review)) and it looked pretty ugly to do in PowerShell.

[refack]

More ugly than:

const cmd = common.isLinux ?
            `ps -o pid,args | grep '${process.pid} ${title}' | grep -v grep` :
            `ps -p ${process.pid} -o args=`;

😜

P.S. https://blogs.msdn.microsoft.com/powershell/2009/05/22/get-windowtitle-ps1/

PS C:\WINDOWS\system32> Get-Process |where {$_.mainWindowTItle} |format-table id,name,mainwindowtitle –AutoSize

   Id Name                 MainWindowTitle
   -- ----                 ---------------
12184 ApplicationFrameHost Calculator
 8392 Calculator           Calculator
16228 chrome               Get-WindowTitle.ps1 | PowerShell Team Blog - Google Chrome
11276 ConEmu64             cmd (Admin)
13504 DontSleep_x64        DontSleep
13420 explorer             Downloads
19240 explorer             D:\code\0tni
21440 mmc                  Event Viewer
14860 powershell           Administrator: PowerShell
20176 pycharm64            node - [D:\code\node] - ...\test\parallel\test-setproctitle.js - PyCharm 2017.2 EAP
 4616 ShellExperienceHost  Windows Shell Experience Host
21464 SystemSettings       Settings
 4632 ThrottleStop         ThrottleStop 6.00
11528 vivaldi              player.gl.bynetcdn.com/Players/ByPlayer/EmbedPlayer/GLZ?ClipID=glglz&type=live

[richardlau]

😲 At the time #11416 landed that was a one liner:

exec(`ps -p ${process.pid} -o args=`, function callback(error, stdout, stderr) {

And yes, still uglier than the current. Quoting myself from the review:

Turns out it's more complicated because on Windows changing the process title changes the title of the console Window which is not necessarily the same process as the node.exe process (e.g. if you open a cmd.exe Window and then launch node.exe inside it, changing the process title in Node.js changes the Window title of the cmd.exe process).

[refack]

Turns out it's more complicated because on Windows changing the process title changes the title of the console Window which is not necessarily the same process as the node.exe process (e.g. if you open a cmd.exe Window and then launch node.exe inside it, changing the process title in Node.js changes the Window title of the cmd.exe process).

True 😞

[richardlau]

Btw I am 👍 for implementing the currently skipped part of the test on Windows -- just wanted to indicate that it's non-trivial.

[refack]

I've found a better than nothing one liner:

    const powerShell = 'powershell -ExecutionPolicy Unrestricted -Command';
    return `${powerShell} "ps | ? {$_.mainWindowTItle -eq '${title}'}"`;

It's a bit looser (will find any window with the title, so might have false positives)

[richardlau]

Might as well copy the rest of my original review:

Anyway I ended up with this hideous command line/PowerShell script, which given a process id will walk up the parent process ids until it finds a process with a non-empty Window title and then print it out:

powershell "$p = <pid>; $t = Get-Process -pid $p ; while ($t.MainWindowTitle -eq '') { $p = Get-WmiObject win32_process | where {$_.processId -eq $p } | select -ExpandProperty parentProcessId; $t = Get-Process -pid $p } Write-Host $t.MainWindowTitle"

Of course Get-Process doesn't know about parent process ids, so the script has to use Get-WmiObject win32_process (which doesn't know about Window titles).

I make no claims to being a PowerShell expert.

I think that will avoid false positives, but IMHO the script is difficult to read/follow (and I was the one who hacked it together 😆 ).

[refack]

Yep so on Windows it's the window that gets the title, so I'm spinning up a new window with cmd /c start "not the mama" /MIN node... PR to come soon