TypeScript Server Error: `length < 0`

[ulugbekna]

🔍 Search Terms

semantic error length < 0

🕗 Version & Regression Information

At least since 5.2.0-dev.20230807 and still reproducible with 5.2.1-rc

⏯ Playground Link

No response

💻 Code

I observe this error with various files in my project but it is closed-source. I imagine this is reproducible with any sufficiently lengthy TS file.

🙁 Actual behavior

An exception is thrown in the dev console AND I suspect this results in some issues with inlay hints being displayed and updated:

ERR <semantic> TypeScript Server Error (5.2.1-rc)
length < 0
Error: length < 0
    at createTextSpan (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:13625:11)
    at createTextSpanFromBounds (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:13630:10)
    at createTextSpanFromNode (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:131742:10)
    at getNodeDisplayPart (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:165012:13)
    at addParameterHints (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164767:23)
    at visitCallOrNewExpression (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164873:9)
    at visitor (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164749:7)
    at visitNode2 (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30083:18)
    at forEachChildInAwaitExpression (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30275:12)
    at forEachChild (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30600:35)
    at visitor (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164758:12)
    at visitNode2 (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30083:18)
    at forEachChildInVariableDeclaration (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30145:123)
    at forEachChild (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30600:35)
    at visitor (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164758:12)
    at visitNodes (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30091:22)
    at forEachChildInVariableDeclarationList (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30310:12)
    at forEachChild (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30600:35)
    at visitor (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164758:12)
    at visitNode2 (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30083:18)
    at forEachChildInVariableStatement (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30307:59)
    at forEachChild (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30600:35)
    at visitor (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164758:12)
    at visitNodes (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30091:22)
    at forEachChildInBlock (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30560:10)
    at forEachChild (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30600:35)
    at visitor (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164758:12)
    at visitNode2 (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30083:18)
    at forEachChildInArrowFunction (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30183:243)
    at forEachChild (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:30600:35)
    at visitor (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js:164758:12)
    at visitNodes (/Applications/Visual Studio Code - Insiders.app/

🙂 Expected behavior

No exception is thrown & inlay hints appear and update more consistently.

Additional information about the issue

I think this problem is highlighted by the fact that I have typescript.inlayHints.parameterNames.enabled set to all.

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This was initially reported in microsoft/vscode#190446

[Andarist]

Could you try bisecting your file in an attempt to narrow it down?

[ulugbekna]

@Andarist Thanks for your prompt response. I tried doing so unsuccessfully but will give it one more try when I get that error.

• From my experience of developing the OCaml language server, such errors, where range start and end are mixed up, come from desugaring changing the expected order of nodes. Could that be the case here?

• Could we change the error message to include the range for which this error happens in this release candidate?

[andrewbranch]

Could we change the error message to include the range for which this error happens in this release candidate?

Not a bad idea—in the meantime, maybe it would be easy enough for you to hack it into the tsserver.js you’re using? The one in typescript on npm is not minified; I’m not sure if VS Code minifies the one they bundle in the app.

[MariaSolOs]

@ulugbekna Thank you for reporting this issue!

Unfortunately I'm having some issues reproducing the error. I understand that you cannot share the entire source code, but @Andarist's suggestion of bisecting the file in order to find the problematic function call that's causing the crash would be really helpful :)

[ulugbekna]

Thanks everyone for help! I don't see this error anymore, so closing the issue.