A VS Code formatter for Markdown that runs Prettier for general formatting and then re-aligns tables by visual width, correctly handling CJK and Emoji characters (full-width = 2, half-width = 1) — precisely what Prettier's byte-length-based alignment gets wrong.
Register it as your Markdown formatter and use Format Document (Shift+Alt+F / Shift+Opt+F) or Format Document With… as usual.
Features
- Prettier-based whole-document Markdown formatting.
- CJK/Emoji-aware table alignment ported from yzhang.markdown-all-in-one's table formatter.
- Fenced code blocks are left untouched, including pipe-tables shown as example code.
- Idempotent: formatting an already-formatted document is a no-op.
Usage
- Open a Markdown file.
- Run Format Document (
Shift+Alt+F). On the first use VS Code may ask you to pick a default formatter — choose Markdown Formatter (CJK-aware tables).
To set it as the default formatter for Markdown, add to your settings:
"[markdown]": {
"editor.defaultFormatter": "wujidadi.md-format-vscode"
}
AI-guidance Markdown variants
Copilot and Claude tooling assign their own language modes to AI-guidance files such as prompt files (*.prompt.md), instructions files (*.instructions.md), chat modes (*.chatmode.md), custom agents (*.agent.md), and skills (SKILL.md), so VS Code no longer treats them as plain Markdown.
This formatter matches files by path (any .md / .markdown file), not by language id, so it is offered on those files too — including ones under .github/ and .claude/.
To make it the default formatter there as well, add a language-scoped entry per mode you use; the language ids are assigned by your installed extensions, so confirm each one via the language indicator in the status bar:
"[prompt]": { "editor.defaultFormatter": "wujidadi.md-format-vscode" },
"[instructions]": { "editor.defaultFormatter": "wujidadi.md-format-vscode" },
"[chatmode]": { "editor.defaultFormatter": "wujidadi.md-format-vscode" }
Settings
| Setting |
Default |
Description |
mdFormat.tablesOnly |
false |
Skip Prettier; only align tables. |
mdFormat.delimiterRowNoPadding |
false |
Remove space padding around the delimiter row. |
mdFormat.normalizeIndentation |
false |
Normalize table indentation to whole tab stops. |
mdFormat.tabSize |
4 |
Tab size used when normalizing indentation. |
mdFormat.doubleWidthUnicodeRanges |
[] |
Override the set of characters treated as double-width. |
mdFormat.narrowOverrideUnicodeRanges |
[] |
Override the set of pictographic characters that actually render half-width. |
Width configuration
Character-width determination can be customized in two ways, applied per field in this order of precedence:
- The two
mdFormat.*UnicodeRanges settings above (when non-empty).
- An
mdformat.config.js file at the workspace-folder root (same format as the CLI's config; exports doubleWidthUnicodeRanges / narrowOverrideUnicodeRanges).
- The built-in defaults.
Relationship to the CLI
This extension shares its formatting core with the md-format CLI (md-fmt) in the same repository, so both produce identical output.
Development
cd extension
npm install
npm run compile # bundle src/extension.js → dist/extension.js via esbuild
Then press F5 from the repository root to launch an Extension Development Host.
License
MIT
