feat: isolate mermaid code

src/hooks/useMarkdown.hook.ts

@@ -1,44 +1,76 @@
-import markdownItClass from '@toycode/markdown-it-class'
-import markdownItLatex from '@vscode/markdown-it-katex'
-import MarkdownIt from 'markdown-it'
-import Renderer from 'markdown-it/lib/renderer'
-import blockEmbedPlugin from 'markdown-it-block-embed'
-import markdownItCheckbox from 'markdown-it-checkbox'
-import markdownItFootnote from 'markdown-it-footnote'
-import MarkdownItGitHubAlerts from 'markdown-it-github-alerts'
-import markdownItIframe from 'markdown-it-iframe'
-import Shikiji from 'markdown-it-shikiji'
-import { Ref, toValue } from 'vue'
+import markdownItClass from "@toycode/markdown-it-class"
+import markdownItLatex from "@vscode/markdown-it-katex"
+import MarkdownIt, { Options, Renderer, Token } from "markdown-it"
+import blockEmbedPlugin from "markdown-it-block-embed"
+import markdownItCheckbox from "markdown-it-checkbox"
+import markdownItFootnote from "markdown-it-footnote"
+import MarkdownItGitHubAlerts from "markdown-it-github-alerts"
+import markdownItIframe from "markdown-it-iframe"
+import Shikiji from "markdown-it-shikiji"
+import { Ref, toValue } from "vue"
 
-import { decodeBase64ToUTF8 } from '@/utils/decodeBase64ToUTF8'
-import { html5Media } from '@/utils/markdown/markdown-html5-media'
-import { twitterPlugin } from '@/utils/markdown/markdown-it-twitter'
+import { decodeBase64ToUTF8 } from "@/utils/decodeBase64ToUTF8"
+import { html5Media } from "@/utils/markdown/markdown-html5-media"
+import { twitterPlugin } from "@/utils/markdown/markdown-it-twitter"
+import mermaid from "mermaid"
+
+const markdownItMermaidExtractor = (md: MarkdownIt) => {
+  const defaultFence =
+    md.renderer.rules.fence ||
+    function (
+      tokens: Array<Token>,
+      index: number,
+      options: Options,
+      _: unknown,
+      self: Renderer,
+    ) {
+      return self.renderToken(tokens, index, options)
+    }
+
+  md.renderer.rules.fence = function (
+    tokens: Array<Token>,
+    index: number,
+    options: Options,
+    env: unknown,
+    self: Renderer,
+  ) {
+    const token = tokens[index]
+
+    if (token.info.trim() === "mermaid") {
+      const content = token.content.trim()
+      return `<pre class="mermaid">\n${md.utils.escapeHtml(content)}\n</pre>\n`
+    }
+
+    return defaultFence(tokens, index, options, env, self)
+  }
+}
 
 const md = new MarkdownIt({
   typographer: true,
-  quotes: ['«\xA0', '\xA0»', '‹\xA0', '\xA0›']
+  quotes: ["«\xA0", "\xA0»", "‹\xA0", "\xA0›"],
 })
   .use(markdownItClass, {
-    h1: ['title', 'is-2'],
-    h2: ['title', 'is-3'],
-    h3: ['title', 'is-4'],
-    h4: ['title', 'is-5'],
-    h5: ['title', 'is-6'],
-    h6: ['title', 'is-6']
+    h1: ["title", "is-2"],
+    h2: ["title", "is-3"],
+    h3: ["title", "is-4"],
+    h4: ["title", "is-5"],
+    h5: ["title", "is-6"],
+    h6: ["title", "is-6"],
   })
+  .use(markdownItMermaidExtractor)
   .use(html5Media)
   .use(blockEmbedPlugin, {
     youtube: {
-      width: '100%',
-      height: 300
-    }
+      width: "100%",
+      height: 300,
+    },
   })
   .use(twitterPlugin)
   .use(markdownItCheckbox)
   .use(markdownItFootnote)
   .use(markdownItLatex)
   .use(markdownItIframe, {
-    width: '100%'
+    width: "100%",
   })
   .use(MarkdownItGitHubAlerts)
 
@@ -46,19 +78,21 @@ const useShikiji = async () => {
   md.use(
     await Shikiji({
       themes: {
-        light: 'vitesse-light',
-        dark: 'vitesse-black'
-      }
-    })
+        light: "vitesse-light",
+        dark: "vitesse-black",
+      },
+    }),
   )
 }
 
 useShikiji()
 
+mermaid.initialize({ startOnLoad: false })
+
 const rules: Renderer.RenderRuleRecord = {
   table_open: () =>
     '<div class="overflow-x-auto"><table class="table table-zebra">',
-  table_close: () => '</table></div>'
+  table_close: () => "</table></div>",
 }
 
 md.renderer.rules = { ...md.renderer.rules, ...rules }
@@ -68,15 +102,15 @@ export const useMarkdown = (defaultPrefix?: Ref<string> | string) => {
   const renderFromUTF8 = (content: string, prefix?: string) =>
     content
       ? md.render(content, {
-          docId: defaultPrefix ? toValue(defaultPrefix) : (prefix ?? '')
+          docId: defaultPrefix ? toValue(defaultPrefix) : (prefix ?? ""),
         })
-      : ''
+      : ""
 
   return {
-    toHTML: (content: string) => (content ? md.render(content) : ''),
+    toHTML: (content: string) => (content ? md.render(content) : ""),
     render: (content: string, prefix?: string) =>
       renderFromUTF8(decodeBase64ToUTF8(content), prefix),
     renderFromUTF8,
-    getRawContent
+    getRawContent,
   }
 }