[Error] TypeError: Cannot read property 'text' of undefined at HelpCompletionFeature.onEvent

[Velocet]

System Details

• Operating system name and version: Windows 10 Enterprise 1709 [10.0.16299.98]
• VS Code version: 1.21.0
• PowerShell extension version: 1.6.0
• Output from $PSVersionTable:

Name                           Value
----                           -----
PSVersion                      5.1.16299.98
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.16299.98
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

code -v
1.21.0
9a199d77c82fcb82f39c68bb33c614af01c111ba
x64

$pseditor.EditorServicesVersion

Major  Minor  Build  Revision
-----  -----  -----  --------
1      6      0      0


code --list-extensions --show-versions
AlanWalk.markdown-toc@1.5.6
bierner.markdown-preview-github-styles@0.1.0
christian-kohler.path-intellisense@1.4.2
DavidAnson.vscode-markdownlint@0.14.0
dbaeumer.vscode-eslint@1.4.7
DotJoshJohnson.xml@1.9.2
ecmel.vscode-html-css@0.2.0
formulahendry.auto-close-tag@0.5.6
formulahendry.auto-rename-tag@0.0.15
formulahendry.code-runner@0.9.2
HookyQR.beautify@1.3.0
KnisterPeter.vscode-github@0.27.1
mdickin.markdown-shortcuts@0.8.1
mkaufman.HTMLHint@0.4.0
mrmlnc.vscode-remark@1.1.0
ms-vscode.csharp@1.14.0
ms-vscode.github-issues-prs@0.9.0
ms-vscode.PowerShell@1.6.0
ms-vsts.team@1.122.0
msjsdiag.debugger-for-chrome@4.2.0
robertohuertasm.vscode-icons@7.21.0
Shan.code-settings-sync@2.9.0
shinnn.stylelint@0.34.2
shuworks.vscode-table-formatter@1.2.1
steve8708.Align@0.2.0
streetsidesoftware.code-spell-checker@1.6.5
streetsidesoftware.code-spell-checker-german@0.1.2
Tyriar.sort-lines@1.5.0
Zignd.html-css-class-completion@1.17.1

$PSVersionTable

Name                           Value
----                           -----
PSVersion                      5.1.16299.98
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.16299.98
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

Issue Description

When using command completion an error gets thrown inside Log (Window):

[2018-03-16 00:01:17.448] [renderer1] [error] Cannot read property 'text' of undefined: TypeError: Cannot read property 'text' of undefined
    at HelpCompletionFeature.onEvent (C:\Users\Velocet\.vscode\extensions\ms-vscode.powershell-1.6.0\src\features\HelpCompletion.ts:49:42)
    at e.fire (c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:88:1012)
    at e.$acceptDirtyStateChanged (c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:627:178)
    at e._doInvokeHandler (c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:587:832)
    at e._invokeHandler (c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:587:550)
    at e._receiveRequest (c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:586:658)
    at e._receiveOneMessage (c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:586:427)
    at c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:585:494
    at c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:588:343
    at c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:87:749
    at e.fire (c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:88:992)
    at Socket.<anonymous> (c:\Program Files\Microsoft VS Code\resources\app\out\vs\workbench\node\extensionHostProcess.js:143:227)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:191:7)
    at readableAddChunk (_stream_readable.js:178:18)
    at Socket.Readable.push (_stream_readable.js:136:10)
    at Pipe.onread (net.js:560:20)

Example: Writing Write-Ho throws an error when pressing Tab to complete the command.

Since i dunno much about the inner workings of VS Code or TypeScript, this is just a guess: The path referenced in the error (C:\Users\Velocet\.vscode\extensions\ms-vscode.powershell-1.6.0\src\features\HelpCompletion.ts) is wrong. The file in questsion is located at C:\Users\Velocet\.vscode\extensions\ms-vscode.powershell-1.6.0\out\src\features\HelpCompletion.js and is a JavaScript file instead of a TypeScript one.

Attached Logs

1521154104-9ebabe1c-9422-485b-954d-4e8dacc678161521154100855.zip

[rjmholt]

I've just tried to reproduce this with Write-Ho<TAB> and couldn't, but if null is occurring there, then perhaps VSCode is sending us a bad message... With some defensive programming, we can just return when we are sent null (although perhaps we still want to log an error there...).

@Velocet TypeScript compiles to JavaScript. So you're quite right that the error is occurring in ...\HelpCompletion.js, but that's under the out directory -- JavaScript here is like the binary output of TypeScript. Pre-compilation it's here

[rjmholt]

Also, thanks for opening an issue!

[rkeithhill]

I have seen it before in the dev tools window. Let me see if I can repro it.

[Velocet]

@rjmholt Thanks for clarification! 👍

Is there anything i can do to help? Maybe a detailed trace or something alike?

[rjmholt]

If you could provide something like that, it would definitely be helpful. The issue as it appears now seems trivial to fix, but I can't reproduce it and VSCode really shouldn't be sending us null messages, which makes me wonder if something stranger is going on

[rjmholt]

Actually, I see above that you've already got a trace. My inclination is to just fix the superficial bug and see if bad things persist -- we lose nothing by being defensive. I will open a PR tonight