ts7022 reported incorrectly

[ristiisa]

Type: Bug

ts7022.mp4

It seems that if "problematic line" is included in this typescript code something breaks and the type of result defaults to any and we get this error:

'result' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.

const get = (i: string): Promise<string | null> => new Promise(resolve => resolve(i));

(async () => {
  let v: string | null = null;

  if(v == null) v = "";

  while(true) {
    const result = await get(v);

    if(result == null) break;

    if(result === v) break; // problematic line
  }
})();

tsc compiles the code fine without any errors. The project has all the default settings:

npm init
npm i -D typescript
npx tsc --init
npx tsc -v                                                                                                                                               
Version 5.0.2

VS Code version: Code 1.76.2 (ee2b180, 2023-03-14T17:55:54.936Z)
OS version: Windows_NT x64 10.0.19045
Modes:
Sandboxed: No

System Info

Item	Value
CPUs	AMD Ryzen 9 3900X 12-Core Processor (24 x 3793)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_renderer: enabled_on video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: disabled_off
Load (avg)	undefined
Memory (System)	63.93GB (28.53GB free)
Process Argv	--crash-reporter-id f0915d69-058f-4338-abf2-5ba99d197a4d
Screen Reader	no
VM	0%

Extensions (14)

Extension	Author (truncated)	Version
jsoncrack-vscode	Ayk	1.0.8
dart-code	Dar	3.61.20230307
flutter	Dar	3.61.20230301
vscode-eslint	dba	2.4.0
LogFileHighlighter	emi	2.16.0
dotenv	mik	1.0.1
jupyter-keymap	ms-	1.1.0
remote-ssh	ms-	0.98.0
remote-ssh-edit	ms-	0.84.0
remote-wsl	ms-	0.76.1
remote-explorer	ms-	0.2.0
vscode-versionlens	pfl	1.5.0
polacode	pnp	0.3.4
vscode-gradle	vsc	3.12.6

A/B Experiments

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pythontb:30283811
vsjup518:30340749
pythonptprofiler:30281270
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vstes263cf:30335440
pythondataviewer:30285071
vscod805:30301674
binariesv615:30325510
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cmake_vspar411:30581797
vsaa593:30376534
pythonvs932:30410667
cppdebug:30492333
vsclangdc:30486549
c4g48928:30535728
dsvsc012cf:30540253
pynewvextcfv2:30681851
azure-dev_surveyonecf:30548226
pyindex848:30662994
nodejswelcome1:30587005
2e4cg342:30602488
pyind779:30671433
89544117:30613380
pythonsymbol12:30671437
6233i204:30672705
vsccsb:30677849
vscodeenable:30660116
defaultazurewalk:30687958
pythonms35:30686772

[IllusionMH]

Looks similar to microsoft/TypeScript#43047 but not sure how check affects type.

[ristiisa]

Looks similar to microsoft/TypeScript#43047 but not sure how check affects type.

In there the issue is in circularity but in this case no circularity exists.

[mjbvz]

Does this reproduce in the latest VS Code insiders build with all extensions disabled?

[ristiisa]

Does this reproduce in the latest VS Code insiders build with all extensions disabled?

After the yesterdays update the issue is no longer reproducible on the insider build. So the update that came on 18 or 20 must have fixed the issue.