Markdown / Markdown Preview improvements - Tracking Issue

[nathansobo]

All Markdown issues

LSP

Investigate this, this may solve multiple other requests

• vscode-markdown-languageservice Markdown LSP support (markdown-language-server) #5243

Syntax highlighting

• . breaks bold markup in Markdown files #5217
• _ breaks highlighting
• MDX extensions#203
• Syntax highlighting for markdown fenced code blocks #5761

Render / Embed

• Render bold text bold, italic text italic, etc.
• Document embedding via multibuffers (@Kethku's suggestion)
• Allow opening links from markdown files in the default browser #992
• Markdown link creation improvements #5087
• Render markdown in comments/doc comments #5313
• Support GFM callouts in Markdown (formerly GitHub admonitions) #10022
• Mermaid diagram rendering in Markdown preview #10696
• Markdown Tables are Misaligned in Preview #11024
• Support images in Markdown preview #13246
• Footnote support in Markdown #13603
• markdown preview code block is not monospace #15379
• Markdown preview: list items should indent #18540
• Markdown preview: code blocks: more horizontal padding #18542
• Markdown preview: Copy button for source code blocks #19061
• Markdown code block font size is too large #19157
• Markdown preview: add svg text support #21319
• markdown preview code blocks: syntax highlighting breaks with leading spaces #23218

Autocomplete / Autoformatting

• Detect lists and automatically insert the appropriate item #5089
• Format Shorthand Markdown Tables #5382
• CMD + Click checkboxes (- [ ]) in MD to fill them #5226

Misc

• markdown preview: Allow clicking on image to navigate to source location #21630
• Markdown preview in browser window #4791
• Markdown outline and folding support #4924
• Spell Checking #5305
• Custom markdown header color #14115
• Support for Emoji Shortcodes

HTML

• markdown preview: support html <kbd> for keystrokes #14830
• preview markdown support for html <img> tags for images #21992
• markdown preview: superscript / subscript support: html <sub> <sup> #22056

[iamnbutler]

I'd love for us to detect checklists as well (- [ ]) and add a new one when making a new line.

[human85]

agree

[fdionisi]

Not sure if the following should be added here on in a separate bug ticket.

When adding italic styling using _ to the last word of a sentence on the last line of the editor, syntax highlight is not applied until you enter a new line below.

Kapture.2022-07-27.at.12.43.44.mp4

[red-co]

Can we add support for id anchor jumps in Markdown, // If possible, allow this specific syntax to jump directly into the editor in any source code comment block.

Some editors allow setting ids or aliases for headers.

It may be implemented with html like <a id="anchor">name</a>, but this hack only works for page html, and editor inside jumps do not support it.

[dimitre]

I've noticed now Zed is trimming down double spaces in the end of line (Markdown code for line break) on file save.
it would be great to be able to keep them in .md files

[mtalexan]

The trimming of trailing whitespace is a formatter setting in Zed. I personally have it disabled globally just for this reason, but maybe there's a way to disable it only for the Markdown language files? I'm not particularly clear which options are available to configure per-language.

[calebmeyer]

Personally, I don't like using invisibles (even if they are rendered on selection or by default) to indicate anything semantically important. I use <br /> tags if I really need a markdown line break, and that lets me keep the "trim trailing whitespace on save" option on.

That said, I am in support of having the option for people who do prefer double space line breaks.

[squingo44]

Default Markdown highlighting doesn't colour headers, which isn't the behaviour I expect coming from other editors:

Zed:

VSCode:

Nvim:

Theme is Catppuccin Mocha

[mtalexan]

I think that's from a specific VSCode Extension, I don't see any such multi-color heading highlighting in mine.

[uncenter]

@mtalexan that would be because your theme doesn't make use of the TextMate scopes for each level. If you run "Developer: Inspect Editor Tokens and Scopes" in the VS Code command palette and click on different Markdown heading levels, you'll observe TextMate scopes such as "heading.1.markdown", "heading.2.markdown", etc.

Same thing for Helix and Neovim, both support specific highlight captures for each level of heading:

https://github.com/helix-editor/helix/blob/8961ae1dc66633ea6c9f761896cb0d885ae078ed/runtime/queries/markdown/highlights.scm#L5-L10

https://github.com/nvim-treesitter/nvim-treesitter/blob/42fc28ba918343ebfd5565147a42a26580579482/queries/markdown/highlights.scm#L2-L26

[mtalexan]

It's important to understand that in Markdown, there's a "standard" Markdown which is pretty limited and very poorly specified. Often what's actually implemented for "standard" Markdown is CommonMark Markdown, which is an actual strict definition for the previously only loosely defined "standard" Markdown format. That's what most formatters and flavors are actually based on.
Markdown flavors are actually custom syntax extensions to the base standard Markdown format, and there are a LOT of them. One of the most popular is GitHub-flavored Markdown, but there are others and often different flavors may have conflicting syntax extensions.
VSCode assumes GitHub-flavored markdown as their default, but currently Zed seems to pick "standard" Markdown as the default. Neither seems to have very good support for other Markdown flavors that I've seen.

On top of Markdown flavors, there are also some document writing features and knowledgebase ease-of-use features that aren't present in Markdown or any of it's major flavors. Markdown has increasingly been getting adopted as an easy rendered document language for knowledge tools (e.g. Roam, Obsidian.md, Notion), and then as a quick Blog website source document format that can be generated from files like that, as well as a rendered research paper/whitepaper source format (as an alternative to Latex). Resultantly there's increasing interest in supporting one-off syntax extensions to simplify use and implementation of some of these features rather than having to fall back to the raw HTML format (which Markdown also supports and allows normally). Some examples of these one-off features are Footnotes, captions, and custom reference anchors. Being able to quickly create them, as well as being able to render them is a two-part issue.