Permalink rendered as markdown

[kwivix]

Operating system

macOS Sequoia 15.6

Eleventy

3.1.2

Describe the bug

With the following config option the permalink of a Markdown file is also rendered as Markdown. Resulting in HTML in the permalink: ./_site/<p>/test/</p>\n.

export const config = {
    markdownTemplateEngine: 'md',
};

Error output:

[11ty] Problem writing Eleventy templates:
[11ty] The template at './a-file.md' attempted to write to './_site/<p>/test/</p>
[11ty] ' (via `permalink` value: '/test/'), which is a target on the file system that does not include a file extension.
[11ty] 
[11ty] You *probably* want to add a file extension to your permalink so that hosts will know how to correctly serve this file to web browsers. Without a file extension, this file may not be reliably deployed without additional hosting configuration (it won’t have a mime type) and may also cause local development issues if you later attempt to write to a subdirectory of the same name.
[11ty] 
[11ty] Learn more: https://v3.11ty.dev/docs/permalinks/#trailing-slashes
[11ty] 
[11ty] This is usually but not *always* an error so if you’d like to disable this error message, add `eleventyAllowMissingExtension: true` somewhere in the data cascade for this template or use `eleventyConfig.configureErrorReporting({ allowMissingExtensions: true });` to disable this feature globally.
[11ty] Wrote 0 files in 0.04 seconds (v3.1.2)
[11ty] Eleventy Fatal Error (CLI):
[11ty] The template at './a-file.md' attempted to write to './_site/<p>/test/</p>
[11ty] ' (via `permalink` value: '/test/'), which is a target on the file system that does not include a file extension.
[11ty] 
[11ty] You *probably* want to add a file extension to your permalink so that hosts will know how to correctly serve this file to web browsers. Without a file extension, this file may not be reliably deployed without additional hosting configuration (it won’t have a mime type) and may also cause local development issues if you later attempt to write to a subdirectory of the same name.
[11ty] 
[11ty] Learn more: https://v3.11ty.dev/docs/permalinks/#trailing-slashes
[11ty] 
[11ty] This is usually but not *always* an error so if you’d like to disable this error message, add `eleventyAllowMissingExtension: true` somewhere in the data cascade for this template or use `eleventyConfig.configureErrorReporting({ allowMissingExtensions: true });` to disable this feature globally.

allowMissingExtensions

With the option allowMissingExtensions the following file is created: _site/<p>/test/</p>

$ cat _site/\<p\>/test/\</p\>$'\n'
<h1>hello world</h1>

Reproduction steps

1. Execute npx @11ty/eleventy with the following files:

a-file.md

---
permalink: /test/
---
# hello world

eleventy.config.js

export const config = {
    markdownTemplateEngine: 'md',
};

Expected behavior

The permalink should be /test/ and a file should be written to _site/test/index.html.

Reproduction URL

No response

Screenshots

No response

[darthmall]

The markdownTemplateEngine setting is used to control what template engine in addition to markdown-it is used to process your markdown files. For example, the default value is “liquid” which means that eleventy will first run your markdown files through the liquid engine, and then run them through markdown-it). Setting this value to md means your markdown templates will be processed by markdown-it twice.

Additionally, Eleventy uses the template’s current rendering engine to parse permalinks, which is how it supports dynamic permalinks. So setting your markdownTemplateEngine to md will cause Eleventy to parse your permalinks as markdown. I’m pretty sure this is expected behavior.

There’s probably no reason to set markdownTemplateEngine: "md", since that will break permalinks and result in your markdown being run through markdown-it twice. If you’re trying to disable liquid parsing of your markdown files, you can set markdownTemplateEngine: false.