How I accidentally wrote my first Neovim plugin

Published June 25, 2025

3 min read

Tags: neovim, lua

Just Show Me The Code

repo

The Problem

There is a simple motion I use in Neovim often and I finally decided to do something about it.

That motion is breaking up single line imports into multiline imports.

Example:

This:

import { foo, bar, baz } from './utils';

Should become:

import {
  foo,
  bar,
  baz,
} from './utils';

It's a tiny thing but something I do all the time in javascript, typescript, and rust. Even if it's less than 80 characters wide, I really like breaking multiple modules imports down to separate lines.

The First Approach: Regex (And Why It Worked)

The very first version of Vandelay used simple Lua string matching:

local pattern = [[import%s*{%s*(.-)%s*}%s*from%s*(.*);]]
local names, from = string.match(line, pattern)

This captured two groups:

• names - the full list inside { ... }
• from - the source string

After capturing, it simply:

• Split names on commas into a table of individual imports
• Trimmed whitespace
• Reconstructed the formatted import line with newlines and indentation

Why It Worked

The format of imports I wanted to modify was extremely predictable. I only cared about one specific form and I was only operating on one line at a time. Lua strings were simple and fast for this very specific case. This worked extremely well from the start and passed some simple tests that tests import structure.

Adding Treesitter (And Why It Didn't Work)

I thought using Treesitter would make the plugin more robust. It sounded like a perfect fit: parse the full AST, extract imports properly, and avoid relying on fragile string patterns.

In practice, I quickly ran into problems:

• Complex Treesitter queries for what seemed like simple tasks
• Accidental full-line and full-file rewrites when I only wanted to touch one line
• Query capture ordering issues that merged unrelated imports together
• Inconsistent grammar across different Treesitter parser versions
• Parser installation requirements that added more dependencies
• Much more boilerplate code for very minimal benefit

Treesitter excels for full-file refactors, linters, or analysis tools. But for surgical, highly structured, one-line rewrites? It was overkill.

What I Learned

Treesitter is powerful. But power doesn’t always equal simplicity — especially for narrowly scoped formatting tasks.

For this plugin, regex provided:

• Faster iteration
• Predictable behavior
• No parser dependencies
• Simple implementation
• Easier testing

Sometimes simple string matching really is enough -- especially when your input format is highly constrained.

nvim-vandelay 1.0

The end result became nvim-vandelay.

• A micro-plugin for formatting imports
• Fully manual keybind control
• Regex-powered single-line rewriting
• Rust and JavaScript support out of the box
• Fully tested via Plenary + CI

Here is another link to the repo: nvim-vandelay