TS language service keeps crashing

Issue Type: Bug

Not at all sure why this happens. One of the stack traces goes like this:

[2022-04-07 17:58:57.661] [exthost] [error] Error: <semantic> TypeScript Server Error (4.6.3)
BADCLIENT: Bad error code, 7027 not found in range 1586..1595 (found: false, false, false, false); could have caused this error:
Debug Failure. Token and statement should start at the same point. {"statementKind":"ReturnStatement","tokenKind":"AsKeyword","errorCode":7027,"start":1586,"length":9}
Error: BADCLIENT: Bad error code, 7027 not found in range 1586..1595 (found: false, false, false, false); could have caused this error:
Debug Failure. Token and statement should start at the same point. {"statementKind":"ReturnStatement","tokenKind":"AsKeyword","errorCode":7027,"start":1586,"length":9}
    at doChange (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:152864:26)
    at /vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:152847:96
    at Function.ChangeTracker.with (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:145719:17)
    at Object.getCodeActions (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:152847:64)
    at /vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:146964:77
    at Object.flatMap (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:508:25)
    at Object.getFixes (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:146964:23)
    at /vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:162191:35
    at Object.flatMap (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:508:25)
    at Object.getCodeFixesAtPosition (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:162189:23)
    at IpcIOSession.Session.getCodeFixes (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:173756:64)
    at Session.handlers.ts.Map.ts.getEntries._a.<computed> (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:172389:61)
    at /vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:174069:88
    at IpcIOSession.Session.executeWithRequestId (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:174060:28)
    at IpcIOSession.Session.executeCommand (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:174069:33)
    at IpcIOSession.Session.onMessage (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:174095:35)
    at process.<anonymous> (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/node_modules/typescript/lib/tsserver.js:176730:31)
    at process.emit (node:events:390:28)
    at emit (node:internal/child_process:917:12)
    at processTicksAndRejections (node:internal/process/task_queues:84:21)
	at Function.create (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/typescript-language-features/dist/extension.js:1:502930)
	at dispatchResponse (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/typescript-language-features/dist/extension.js:1:496778)
	at dispatchMessage (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/typescript-language-features/dist/extension.js:1:495646)
	at ChildProcess.<anonymous> (/vscode/vscode-server/bin/linux-x64/e18005f0f1b33c29e81d732535d8c0e47cafb0b5/extensions/typescript-language-features/dist/extension.js:1:495131)
	at ChildProcess.emit (node:events:390:28)
	at emit (node:internal/child_process:917:12)
	at processTicksAndRejections (node:internal/process/task_queues:84:21)

VS Code version: Code 1.66.0 (e18005f0f1b33c29e81d732535d8c0e47cafb0b5, 2022-03-30T05:50:04.419Z) OS version: Darwin x64 20.6.0 Restricted Mode: No Remote OS version: Linux x64 5.10.76-linuxkit

System Info

Item	Value
CPUs	Intel® Core™ i7-8750H CPU @ 2.20GHz (12 x 2200)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_renderer: enabled_on video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled
Load (avg)	6, 6, 5
Memory (System)	16.00GB (0.22GB free)
Process Argv	–crash-reporter-id 961ba054-15e1-4479-bbbb-27dee222b72d
Screen Reader	no
VM	0%

Item	Value
Remote	Dev Container: Node.js
OS	Linux x64 5.10.76-linuxkit
CPUs	Intel® Core™ i7-8750H CPU @ 2.20GHz (6 x 2200)
Memory (System)	3.84GB (0.40GB free)
VM	0%

Extensions (9)

Extension	Author (truncated)	Version
ndjson-colorizer	bus	1.0.0
jupyter-keymap	ms-	1.0.0
remote-containers	ms-	0.231.5
remote-ssh	ms-	0.78.0
remote-ssh-edit	ms-	0.80.0
debugger-for-chrome	msj	4.13.0
vscode-eslint	dba	2.2.2
go	gol	0.32.0
vscode-docker	ms-	1.21.0

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pythonvs932:30410667
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pynewfile477:30463512

[DanielRosenwasser]

Thank you @rhefner - here’s a minimal repro based on that.

here’s a repro:

// bar.ts
import * as foo from './foo'
export as namespace foo
export = foo;

declare global {
    const foo: typeof foo;
}

// foo.d.ts
interface Root {
    /**
     * A .default property for ES6 default import compatibility
     */
    default: Root;
}

declare const root: Root;
export = root;

[rhefner]

Cannot read properties of undefined (reading ‘flags’)

This is also happening to me … At least in my case, seems related to #40991 as commenting out esModuleInterop from my tsconfig.json stops the crashing and re-enabling it reintroduces the crashes. Happens with all extensions disabled, no .vscode/ files in the repo and also happens on VSCode Insiders. Using a PNPM monorepo w/typescirpt@4.7.3, but also tried with typescript@next (4.8.0-dev.20220624) with the same result.

Here’s a copy of the tsserver.log with the private stuff redacted: https://gist.github.com/rhefner/5ad0aa5225d9e56ad2e436c0eb885a83

UPDATE

My issue seems to be caused by one of my ambient type files (loglevel.d.ts) - Commenting out export = log stops the crashes, but also do a few other modifications.

import * as log from 'loglevel'
export as namespace log
export = log // Commenting this out stops the crashes in my case

declare global {
  const log: typeof log
}

…Not sure why that’s crashing tsserver, as it seems that’s it’s allowed - I’m probably missing something very trivial. 😅 Anyways, changing it around to this seems to fix the crashes for me:

declare global {
  const log: typeof import('loglevel')
}

export {}