chunks[startIndex].slice is not a function

[eikowagenknecht]

I'm trying to use this is Astro. Unfortunately, when at least one callout is present on the page, rendering crashes:

Failed to parse Markdown file "C:\Entwicklung\repos\eiko-wagenknecht.de\src\content\posts\markdown-test.md":
chunks[startIndex].slice is not a function

Stack Trace:

TypeError: Failed to parse Markdown file "C:\Entwicklung\repos\eiko-wagenknecht.de\src\content\posts\markdown-test.md":
chunks[startIndex].slice is not a function
    at sliceChunks (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/micromark@4.0.0/node_modules/micromark/lib/create-tokenizer.js:512:32)
    at Object.sliceStream (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/micromark@4.0.0/node_modules/micromark/lib/create-tokenizer.js:153:12)
    at insideTitle (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/remark-callout@1.1.1/node_modules/remark-callout/dist/lib/micromark-syntax.js:105:33)
    at afterTypePotentialWhitespace (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/remark-callout@1.1.1/node_modules/remark-callout/dist/lib/micromark-syntax.js:100:16)
    at go (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/micromark@4.0.0/node_modules/micromark/lib/create-tokenizer.js:222:13)
    at main (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/micromark@4.0.0/node_modules/micromark/lib/create-tokenizer.js:208:9)
    at Object.write (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/micromark@4.0.0/node_modules/micromark/lib/create-tokenizer.js:129:5)
    at fromMarkdown (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/mdast-util-from-markdown@2.0.1/node_modules/mdast-util-from-markdown/lib/index.js:173:66)
    at parser (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/remark-parse@11.0.0/node_modules/remark-parse/lib/index.js:33:12)
    at Function.parse (file:///C:/Entwicklung/repos/eiko-wagenknecht.de/node_modules/.pnpm/unified@11.0.5/node_modules/unified/lib/index.js:668:12)

Input:

> [!example]
> Example

package.json:

  "dependencies": {
    "@astrojs/mdx": "3.1.2",
    "@astrojs/partytown": "2.1.1",
    "@astrojs/react": "3.6.0",
    "@astrojs/rss": "4.0.7",
    "@astrojs/sitemap": "3.1.6",
    "@astrojs/tailwind": "5.1.0",
    "@radix-ui/react-dialog": "1.1.1",
    "@types/mdast": "4.0.4",
    "astro": "4.11.5",
    "hast-util-from-html-isomorphic": "2.0.0",
    "react": "18.3.1",
    "react-dom": "18.3.1",
    "rehype-autolink-headings": "7.1.0",
    "rehype-slug": "6.0.0",
    "remark-callout": "^1.1.1",
    "remark-github-blockquote-alert": "1.2.1",
    "remark-obsidian-callout": "1.1.3",
    "remark-toc": "9.0.0",
    "sanitize-html": "2.13.0",
    "unified": "11.0.5",
    "unist-util-visit": "5.0.0"
  },
  "devDependencies": {
    "@astrojs/check": "0.8.0",
    "@biomejs/biome": "1.8.3",
    "@commitlint/cli": "19.3.0",
    "@commitlint/config-conventional": "19.2.2",
    "@commitlint/types": "19.0.3",
    "@tailwindcss/forms": "0.5.7",
    "@tailwindcss/typography": "0.5.13",
    "@types/react": "18.3.3",
    "@types/react-dom": "18.3.0",
    "lefthook": "1.7.1",
    "prettier": "3.3.2",
    "prettier-plugin-astro": "0.14.0",
    "prettier-plugin-tailwindcss": "0.6.5",
    "tailwindcss": "3.4.4",
    "typescript": "5.5.3"
  }

The other alternative plugins work fine (with their limited functionality).

[rk-terence]

Hi, thank you for your report and sorry for the late reply. This issue looks a little weird, and it might be related to depencencies this package use. I have found a similar issue here in the micromark GitHub repo. The dependency "micromark-utils-character" might be causing the problem. Further investigation is needed, and I will work on this to reach a solution when I can spare some time.

Testing locally on my machine works fine. My exact local version of dependency "micromark-util-character" is 2.0.1.
As a temporary fix, maybe specifying

"micromark-util-character": "2.0.1"

in your package.json can solve your problem (note there is no caret symbol before the version number).

[eikowagenknecht]

Pinning 2.0.1 does not fix this. Thanks for investigating, though!