Enable Syntax Highlighting for .keymap Files in Neovim

I’ve made a few minor tweaks to my keyboard layout (both in qmk and zmk) in the last few weeks. Each time, I’ve been annoyed with the non-highlighted text of the .keymap files when I edit them in neovim. I learned how to fix this, and the solution is very simple.

Background

Neovim has been my editor of choice for awhile now, especially when in a terminal. I converted my configuration to a .lua setup, with treesitter for syntax highlighting about a year ago. Generally, this works well. However, the system didn’t recognize to use c highlighting for my keymap files.

:setfiletype

After some digging, I was reminded about the setfiletype option in vim. This lets you change the buffer’s file type. For example, :setfiletype markdown. When I tried setting the buffer to c, everything looked much better.

Adding to my Configuration

With a potential fix, I wanted to add it to the configuration to keep it persistent. I didn’t feel like converting this to the equivalent lua, so I just used a vim.cmd in the general file of my home-manager neovim configuration:

-- Generally read .keymap files as C ones
vim.cmd[[autocmd BufNewFile,BufRead *.keymap setfiletype c]]

This line tells vim to set the file type to c for any file that ends in .keymap. Maybe one day I’ll convert it to lua, but for now … it works 😄.

Conclusion

After adding that line and rebuilding my home-manager config, neovim opens .keymap files with syntax highlighting on all my machines. Quick and simple!