HTML Intellisense crashes: "Cannot read property 'length' of undefined"

[mjbvz]

From @tsalinger on March 29, 2018 13:58

Issue Type: Bug

1. Create an empty html file and paste this in:

<script>
    require.config({
            catchError: true,
            baseUrl: "file://$$ABS_PATH_TO_ROOT$$/out/browser/",
            paths: {
                 <|>
            }
        });
</script>

2. Insert double quotes at the cursor position <|> (the problem only occurs when using doubles quotes).

Resulting error:

[Error - 15:53:15] Error while computing completions for file:///c%3A/vscode_projects/test/htmlIntellisenseIssue/main.html: Cannot read property 'length' of undefined
TypeError: Cannot read property 'length' of undefined
    at getCompletionEntriesFromSymbols (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\node_modules\typescript\lib\typescript.js:84803:65)
    at convertStringLiteralCompletions (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\node_modules\typescript\lib\typescript.js:84644:21)
    at Object.getCompletionsAtPosition (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\node_modules\typescript\lib\typescript.js:84609:23)
    at Object.getCompletionsAtPosition (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\node_modules\typescript\lib\typescript.js:103260:35)
    at doComplete (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\html-language-features\server\out\modes\javascriptMode.js:78:49)
    at Object.<anonymous> (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\html-language-features\server\out\htmlServerMain.js:320:38)
    at step (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\html-language-features\server\out\htmlServerMain.js:36:23)
    at Object.next (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\html-language-features\server\out\htmlServerMain.js:17:53)
    at fulfilled (c:\Program Files\Microsoft VS Code Insiders\resources\app\extensions\html-language-features\server\out\htmlServerMain.js:8:58)
    at <anonymous>

VS Code version: Code - Insiders 1.22.0-insider (952b2a6, 2018-03-29T05:17:25.524Z)
OS version: Windows_NT x64 10.0.16299

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-4600U CPU @ 2.10GHz (4 x 2694)
Memory (System)	7.88GB (2.77GB free)
Process Argv	C:\Program Files\Microsoft VS Code Insiders\Code - Insiders.exe
Screen Reader	no
VM	0%

Extensions (13)

Extension	Author (truncated)	Version
vscode-css-formatter	aes	1.0.1
numbered-bookmarks	ale	0.11.1
regex	chr	0.1.0
vscode-eslint	dba	1.4.8
gitlens	eam	8.1.1
tslint	eg2	1.0.28
vsc-material-theme	Equ	1.5.1
python	ms-	2018.2.1
debugger-for-chrome	msj	4.3.0
gitlink	qez	0.4.2
ayu	tea	0.14.0
vscode-todo-highlight	way	0.5.12
markdown-pdf	yza	0.1.8

(3 theme extensions excluded)

Copied from original issue: microsoft/vscode#46939

[mjbvz]

Root cause seems to be that in getCompletionsAtPosition, convertStringLiteralCompletions is called with the result of getStringLiteralCompletionEntries. In this case, getStringLiteralCompletionEntries returns what looks like an invalid completion with no symbols.

Haven't been able to reproduce this using TS Server yet

Hm, StringLiteralCompletionsFromProperties#symbols comes from type.getApparentProperties which calls getAugmentedPropertiesOfType which calls getNamedMembers which does return result || emptyArray;, so it should always be defined.

What ts version was this?

[mjbvz]

2.8.1. It was returning an array with one element:

[{ kind: 1, symbols: undefined }]

2.8.1 doesn't match the line numbers in the stack trace above (e.g. line 84803 is in getEncodedSemanticClassifications, not getCompletionEntriesFromSymbols), or did you repro the issue yourself?

[mjbvz]

I can repo this in 2.8.1. The original stack track may have been from a 2.8.0-insiders. Here's one from 2.8.1:

[Error - 11:43:18] Error while computing completions for file:///Users/matb/projects/san/sub/a/bar.html: Cannot read property 'length' of undefined
TypeError: Cannot read property 'length' of undefined
    at getCompletionEntriesFromSymbols (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/typescript.js:84803:65)
    at convertStringLiteralCompletions (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/typescript.js:84644:21)
    at Object.getCompletionsAtPosition (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/typescript.js:84609:23)
    at Object.getCompletionsAtPosition (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/typescript.js:103260:35)
    at doComplete (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/html-language-features/server/out/modes/javascriptMode.js:78:49)
    at Object.<anonymous> (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/html-language-features/server/out/htmlServerMain.js:320:38)
    at step (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/html-language-features/server/out/htmlServerMain.js:36:23)
    at Object.next (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/html-language-features/server/out/htmlServerMain.js:17:53)
    at fulfilled (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/html-language-features/server/out/htmlServerMain.js:8:58)
    at <anonymous>

[mhegazy]

@Andy-MS we will need a fix for 2.8.2 for this one.

My bad, was looking at tsserver.js instead of typescript.js.