Expandable hovers for TypeScript don't appear

[crystalfp]

Type: Bug

1. Open a typescript file
2. hower a type
3. there are no expandable hovers

VS Code version: Code 1.103.0 (e3550cf, 2025-08-06T21:40:10.271Z)
OS version: Windows_NT x64 10.0.26100
Modes:

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz (12 x 2592)
GPU Status	2d_canvas: enabled 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_graphite: disabled_off trees_in_viz: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	31.77GB (15.44GB free)
Process Argv	--crash-reporter-id df3b806e-c371-4e03-89b8-d13088946634
Screen Reader	no
VM	0%

Extensions (87)

Extension	Author (truncated)	Version
Bookmarks	ale	13.5.0
vscode-working-memory	ato	1.0.2
github-markdown-preview	bie	0.3.0
markdown-footnotes	bie	0.1.1
markdown-mermaid	bie	1.28.0
markdown-yaml-preamble	bie	0.1.0
glsl-literal	boy	1.0.6
vscode-toggle-quotes	Bri	0.3.6
vscode-pandoc	Chr	0.6.2
refactorix	chr	0.3.7
bracket-select	chu	2.0.2
markdown-word-count	Cur	0.0.7
vscode-eslint	dba	3.0.16
eslint-disable-snippets	drK	1.4.1
gitlens	eam	17.3.3
vscode-great-icons	emm	2.1.119
vue-3-vscode-snippets	exe	0.8.0
vscode-todo-plus	fab	4.19.1
auto-close-tag	for	0.5.15
seito-openfile	Fr4	2.3.0
copilot	Git	1.350.0
copilot-chat	Git	0.30.0
geminicodeassist	goo	2.44.0
todo-tree	Gru	0.0.226
vscode-webtilities	Har	3.1.3
vue-snippets	hol	1.0.4
plantuml	jeb	2.18.1
code-eol	jef	1.0.12
vscode-peacock	joh	4.2.2
jsdoc-generator	kim	0.0.4
tag-rename	kri	0.2.1
stack-tabs	kyl	0.0.2
git-graph	mhu	1.30.0
prettify-json	moh	0.0.3
tab-cycle	mpo	1.0.1
debugpy	ms-	2025.10.0
isort	ms-	2025.0.0
python	ms-	2025.12.0
vscode-pylance	ms-	2025.7.1
vscode-python-envs	ms-	1.2.0
jupyter	ms-	2025.7.0
jupyter-keymap	ms-	1.1.2
jupyter-renderers	ms-	1.3.0
vscode-jupyter-cell-tags	ms-	0.1.9
vscode-jupyter-slideshow	ms-	0.1.6
cpptools	ms-	1.27.0
hexeditor	ms-	1.11.1
notepadplusplus-keybindings	ms-	1.0.7
vscode-speech	ms-	0.16.0
vscode-speech-language-pack-it-it	ms-	0.5.0
color-highlight	nau	2.8.0
gremlins	nho	0.26.0
abracadabra	nic	9.9.0
pandocciter	not	0.10.4
leaper	Onl	0.10.5
vscode-jscpd	pau	0.3.4
bib	phr	0.3.0
git-file-history	pom	1.0.1
vscode-thunder-client	ran	2.37.4
vscode-yaml	red	1.18.0
vscode-file-templates	rio	1.18.0
pandoc-markdown	rso	0.1.2
vscode-javascript-booster	sbu	14.0.1
vue-vscode-snippets	sdr	3.2.0
trailing-spaces	sha	0.4.1
markdown-preview-enhanced	shd	0.8.18
vscode-scss-formatter	sib	3.0.0
vscode-autohide	sir	1.0.10
shader	sle	1.1.5
stardog-rdf-grammars	sta	0.2.1
code-spell-checker	str	4.0.47
code-spell-checker-italian	str	1.1.4
unique-window-colors	stu	1.0.51
vscode-stylelint	sty	1.5.3
sass-indented	syl	1.8.33
open-in-browser	tec	2.0.0
d2	Ter	0.8.8
highlight-matching-tag	vin	0.11.0
intellicode-api-usage-examples	Vis	0.2.9
vscodeintellicode	Vis	1.3.2
explorer	vit	1.26.4
volar	Vue	3.0.5
vue-mess-detector	Web	0.7.0
change-case	wma	1.0.0
JavaScriptSnippets	xab	1.8.0
pretty-ts-errors	Yoa	0.6.1
markdown-all-in-one	yzh	3.6.3

(2 theme extensions excluded)

[mjbvz]

Please share a self contained code example (as text) that shows the problem so we can investigate

[crystalfp]

interface EstimatorResult {
    /** Minimum local dimension computed value */
    min: number;
    /** Maximum local dimension computed value */
    max: number;
    /** Estimated intrinsic dimensionality */
    avg: number;
    /** Theoretical value for the intrinsic dimensionality */
    theory: number;
}
export const embeddedDimensionEstimator = (): EstimatorResult => {

   return {min: 0, max: 0, avg: 0, theory: 0};
};

Hover on EstimatorResult. There are no expandable hovers in the popup.

[mjbvz]

Thanks. Does this reproduce with all extensions disabled? We've seen a few cases where TypeScript plugins/extensions break this feature

[crystalfp]

@mjbvz you are right. No problem with extensions disabled.
With extension bisect found the vue:volar extension is the one that inhibits expandable hovers.
Should I open an issue to it?

[Quacken8]

I also used >Help: Start Extension Bisect and found that in my case the astro-build.astro-vscode extension being the culprit

[mjbvz]

Thanks for checking! Yes please open issues against those extensions so they can take a look. You can point them to me if they have any questions about what to look into for this

[lishaduck]

I realized all of those extensions use Volar, which merged in support ~2 weeks ago, so the extensions probably just need to get rebuilt with an updated Volar.