Markdown syntax highlighting not working as expected

[huijing]

Type: Bug

Syntax highlighting for .md files and .mdx files is not behaving as expected. This is a recent observation in spite of not changing any of my theme or code settings. Unclear if it was introduced during one of the latest releases. The syntax highlighter is not identifying markdown specific things like double asterisks for bold, or backticks for code, or codeblocks between triple backticks. So it seems like the syntax highlighter forgot how to understand markdown?

VS Code version: Code - Insiders 1.92.0-insider (Universal) (34f8428, 2024-07-04T05:50:23.194Z)
OS version: Darwin arm64 23.5.0
Modes:

System Info

Item	Value
CPUs	Apple M2 Max (12 x 2400)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on 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 video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled webgpu: enabled
Load (avg)	2, 2, 3
Memory (System)	32.00GB (0.24GB free)
Process Argv	--crash-reporter-id 45285dfb-8eb6-4407-8123-fb10f0bf8622
Screen Reader	no
VM	0%

Extensions (21)

Extension	Author (truncated)	Version
astro-vscode	ast	2.10.2
language-hugo-vscode	bud	1.3.1
vscode-eslint	dba	3.0.10
gitlens	eam	15.1.0
prettier-vscode	esb	10.4.0
copilot-chat	Git	0.17.0
vscode-github-actions	git	0.26.3
vscode-graphql	Gra	0.11.0
vscode-graphql-execution	Gra	0.2.6
vscode-graphql-syntax	Gra	1.3.6
vscode-duplicate	mrm	1.2.1
remote-containers	ms-	0.376.0
twig-language-support	rho	1.0.1
nunjucks	ron	0.3.1
vscode-drupal	sta	0.4.4
code-spell-checker	str	3.0.1
even-better-toml	tam	0.19.2
vscode-mdx	uni	1.8.9
gistfs	vsl	0.6.0
console-ninja	Wal	1.0.327
pretty-ts-errors	Yoa	0.5.4

(1 theme extensions excluded)

A/B Experiments

vsliv368:30146709
vspor879:30202332
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pythonnoceb:30776497
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pythonmypyd1:30859725
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dsvsc016:30879898
dsvsc017:30880771
dsvsc018:30880772
cppperfnew:30980852
pythonait:30973460
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dvdeprecation:31040973
dwnewjupytercf:31046870
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impr_priority:31057980
nativerepl1:31071684
refactort:31084545
pythonrstrctxt:31089940
4930e709:31088354

[RedCMD]

caused by microsoft/vscode-markdown-tm-grammar#162 and #219833

[postylem]

I would add for what its worth it seems it is the presence of yaml frontmatter breaks the syntax highlighting in markdown files...

[fweth]

Somehow my VSCode (1.92.0-insider) doesn't understand frontmatter although the online version (insiders.vscode.dev) understands it. I disabled all extensions.

[postylem]

To give a little more detail on when the bug shows up: it seems the highlighting breaks only when there is more than one key in the YAML header.

with only one line in the YAML header, highlighting works

adding the line date: today breaks the highlighting

version info:

Version: 1.92.0-insider
Commit: 4d17e85
Date: 2024-07-26T13:12:28.318Z
Electron: 30.1.2
ElectronBuildId: 9870757
Chromium: 124.0.6367.243
Node.js: 20.14.0
V8: 12.4.254.20-electron.0
OS: Darwin arm64 23.5.0

[RedCMD]

I can confirm it is fixed in the current latest insiders

[postylem]

That's odd, I believed I was using the latest version. Checking for updates informs me there are no updates, however now I see there are indeed later commits. I'll wait for the next build, I suppose.

[VSCodeTriageBot]

Thanks for creating this issue! We figured it's covering the same as another one we already have. Thus, we closed this one as a duplicate. You can search for similar existing issues. See also our issue reporting guidelines.

Happy Coding!

[memeplex]

Quarto extension syntax highlighting has seemingly been affected by this after latest VSCode upgrade: quarto-dev/quarto#501