Why my Hugo Archetypes didn't work

A short story about Hugo template files and Markdown file extensions.

Brief overview of archetypes in Hugo

The current version of my personal blog is built with Hugo, a static site generator. Hugo has the concept of archetypes, which are template files used to create new content types with the hugo new command. It saves you having to copy and paste customised front matter (the YAML, TOML or JSON data at the top of the file) or other custom content every time you create a new post.

Each content type in your Hugo site can have its own archetype template. For example, on my site I create standard blog posts and also custom diary style posts, as content types blog and dev-diary. When I type the command hugo new dev-diary/example-post.md I want the file created to have different YAML fields than one created with hugo new blog/example-post.md

The previous version of my blog was built with Jekyll, and I built my own Yeoman generator in order to achieve the same result as Hugo's archetypes feature (plus it was a fun side-project). Archetypes have been a lot simpler to work with than a hand-made Yeoman generator, except for this one problem I was having.

The issue

I dutifully followed the instructions to create an archetype file from Hugo’s docs and added it in the archetypes directory of my site, so it looked like this:

archetypes
├── default.md
└── blog.md

I used the command hugo new blog/post.markdown but my new "blog" archetype wasn't being used. Instead, the new post used the "default" archetype. I was intermittently having success with it using different filenames but couldn’t work out why. I thought using the "-kind" flag helped but it turned out to be a red herring. I abandoned custom archetypes for a time, although still checked my broken attempts into my blog site repo (because why not?).

The facepalm moment 💡

I recently renamed one of my content types (interesting to dev-diary) and changed the format of my filenames and magically my archetypes began working! But why?

The markdown file extension of my new content file wasn’t matching the extension of the archetype 🤦‍♀️

By using the command hugo new blog/post.markdown, the blog archetype wasn't being invoked correctly, because it had a different file extension to the template file, i.e. archetypes/blog.md. The mismatch between ".markdown" and ".md" extensions caused the archetypes to fail.

Instead I needed to use hugo new blog/post.md and match the markdown file suffixes.

Both ".markdown" and ".md" are valid extensions for Markdown files and I use them interchangeably. Perhaps the ".markdown" extension isn't intended to work with archetypes as a conscious design choice from the Hugo team, but this definitely stumped me for a while!