migrate-mdc-to-comark

name	migrate-mdc-to-comark
description	Migrate a Nuxt project from @nuxtjs/mdc to Comark. Covers package changes, parse/render API mapping, AST format, Nuxt module config, components, slots, plugins, and Nuxt UI integration.

Migrate from @nuxtjs/mdc to Comark

@nuxtjs/mdc was Nuxt-only. Comark is its successor — the markdown syntax is fully compatible, your .md files need no changes. What changes is the JavaScript API.

The migration has two parts: Core Package (programmatic API) and Nuxt Module (components, slots, config).

Quick Overview

• Package: @nuxtjs/mdc → comark (core only) or @comark/nuxt (Nuxt module)
• Parse: parseMarkdown() → parse() · factory: createParse() (sync, no await)
• Render: stringifyMarkdown() → renderMarkdown() from comark/render
• AST: object tree → compact tuples ['tag', props, ...children]
• Result: result.body / result.data → tree.nodes / tree.frontmatter
• Renderer: <MDCRenderer :body :data> → <ComarkRenderer :tree>
• All-in-one: <MDC :value> → <Comark :markdown>
• Slots: <MDCSlot /> → native <slot />
• Plugins: global nuxt.config → per-component defineComarkComponent({ plugins })
• Markdown files: no changes needed

Core Package

API Mapping

@nuxtjs/mdc	comark
parseMarkdown(md, opts)	parse(md, opts) from comark
createMarkdownParser(opts) (async)	createParse(opts) (sync — no await)
stringifyMarkdown(body, data)	renderMarkdown(tree) from comark/render
result.body (MDCRoot)	tree.nodes (ComarkNode[])
result.data	tree.frontmatter
result.data.title	tree.frontmatter.title
result.toc	tree.meta.toc (requires toc plugin)
result.excerpt	tree.meta.summary (requires summary plugin)

AST Format

@nuxtjs/mdc	comark
{ type: 'root', children: MDCNode[] }	{ nodes: ComarkNode[], frontmatter: {}, meta: {} }
{ type: 'element', tag: 'p', props: {}, children: [] }	['p', {}, ...children]
{ type: 'text', value: 'hello' }	'hello' (plain string)

Parse Options

// Before — MDCParseOptions
{
  remark: { plugins: { /* record */ } },
  rehype: { options: {...}, plugins: { /* record */ } },
  highlight: { theme: '...', langs: [...] } | false,
  toc: { depth: 3, searchDepth: 2 } | false,
}

// After — ParseOptions
{
  plugins: ComarkPlugin[],   // ordered array, not a record
  autoUnwrap: true,          // removes <p> from single-paragraph containers
  autoClose: true,           // completes incomplete syntax (useful for streaming)
  html: true,                // parse embedded HTML tags
}

Plugins

The unified/remark/rehype pipeline is replaced by Comark's own lighter plugin interface.

Feature	Before	After
Syntax highlighting	rehypeHighlight via createMarkdownParser	highlight() from comark/plugins/highlight
Table of Contents	parseMarkdown(md, { toc: { depth: 3 } })	toc({ depth: 3 }) plugin
Excerpt / Summary	result.excerpt (built-in)	summary() plugin → tree.meta.summary
Emoji	remark-emoji (enabled by default)	emoji() plugin (opt-in)

Available plugins: comark/plugins/toc, comark/plugins/highlight, comark/plugins/emoji, comark/plugins/task-list, comark/plugins/summary, comark/plugins/security, comark/plugins/alert, comark/plugins/math, comark/plugins/mermaid, comark/plugins/punctuation

Nuxt Module

Configuration

// Before
export default defineNuxtConfig({
  modules: ['@nuxtjs/mdc'],
  mdc: { highlight: { ... }, remarkPlugins: { ... } },
})

// After
export default defineNuxtConfig({
  modules: ['@comark/nuxt'],
  // No plugin config here — plugins are defined per-component
})

@comark/nuxt auto-imports: Comark, ComarkRenderer, defineComarkComponent, defineComarkRendererComponent.

Components

@nuxtjs/mdc	@comark/nuxt
<MDCRenderer :body :data :components>	<ComarkRenderer :tree :components>
<MDC :value :parser-options>	<Comark :markdown :options> or <Comark>{{ md }}</Comark>
<MDCSlot />	<slot />
<MDCSlot unwrap="p" />	<slot unwrap="p" />
<slot mdc-unwrap="p" />	<slot unwrap="p" />

For a pre-parsed tree, use <ComarkRenderer> directly instead of <Comark>.

<ComarkRenderer> props changes

MDC <MDCRenderer>	Comark <ComarkRenderer>	Notes
body (MDCRoot)	tree (ComarkTree)	Different AST shape
data	—	Frontmatter is in tree.frontmatter
tag	—	Wrapper is always <div class="comark-content">
prose	—	Prose* resolution is automatic
unwrap	—	Use autoUnwrap in parse options
components	components	Same purpose
—	componentsManifest	New: dynamic async component resolver
—	streaming	New: streaming mode
—	caret	New: animated caret for streaming

Summary rendering

<!-- Before -->
<MDCRenderer :body="result.excerpt ?? result.body" :data="result.data" />

<!-- After -->
<Comark summary>{{ markdown }}</Comark>

defineComarkComponent

Replaces global mdc: { ... } config. Define reusable components with their own plugins and component mappings:

import { defineComarkComponent } from '@comark/vue'
import highlight from 'comark/plugins/highlight'
import toc from 'comark/plugins/toc'

export const ArticleComark = defineComarkComponent({
  name: 'ArticleComark',
  plugins: [highlight({ themes: { light: githubLight, dark: githubDark } }), toc()],
  components: { alert: CustomAlert },
})

Slots

<MDCSlot /> → native <slot />. Named slots work the same (#slotName in markdown, <slot name="slotName"> in component). The unwrap attribute (<slot unwrap="p">) strips wrapper tags from children.

Prose Components

Same Prose*.vue naming convention in components/prose/. Resolution changed from kebab-case (prose-p) to PascalCase (ProseP) internally — no file changes needed.

Nuxt UI Integration

When using Nuxt UI, @comark/nuxt registers Nuxt UI prose components automatically. Shorthand callout components are available:

::note    — informational
::tip     — helpful suggestion
::warning — something to watch out for
::caution — critical warning

These are only available with Nuxt UI. Without it, use ::callout{icon="..." color="..."}.

Common Pitfalls

1. createParse is sync — no await needed (unlike createMarkdownParser)
2. Attribute naming: Comark uses attrs.lang, not attrs.language
3. Frontmatter: stored in tree.frontmatter, not passed separately
4. renderMarkdown includes frontmatter — reads tree.frontmatter automatically
5. No unified pipeline — mdc.config.ts hooks (pre, remark, rehype, post) have no equivalent, use ComarkPlugin interface instead
6. Emoji is opt-in — not enabled by default like in MDC's remark-emoji

Component Syntax

The MDC block and inline component syntax is identical — no changes needed in .md files.

Unsupported Features

• Binding syntax ({{ variable }}) — not supported, rendered as plain text
• Props binding / data passing — no equivalent for parseMarkdown(md, { data: { ... } })