barely-a-dev-server

barely-a-dev-server

A thin, opinionated wrapper for esbuild as a .ts web server. Given an entryRoot folder, it:

• finds all .ts files under entryRoot and uses them as entry files to run esbuild in watch mode, and
• serves the built .js files together with a fallback to entryRoot for static files.
  • Paths ending in / are mapped to index.html in the corresponding folder.

When run with "dev": false, it writes these files to an output dir (dist/ + the entry root by default), ready to serve using your favorite static file server.

Example

// script/build.js
import { barelyServe } from "barely-a-dev-server";

barelyServe({
  entryRoot: "src", // the only required arg
  dev: true,
  port: 3333,
  esbuildOptions: {
    target: "esnext",
  },
});

---

<!-- src/index.html -->
<script src="./index.js" href="./index.ts" type="module" defer></script>

// src/index.ts
const a: number = 4;
console.log(a);

(Note that src must reference the .js file, not .ts. The example shows a hack: you can use href to store a reference to the .ts source, which works with e.g. "Follow link" in VSCode.)

Why barely-a-dev-server?

• Works just as well as fancy bundlers, if all your code is TypeScript.
• No dependencies.
• Less than 200 lines of source code (unminified).

Why not barely-a-dev-server?

• Hardcoded to assume that you are only using TypeScript for your source and ESM for your output.
• No CLI.
  • If you don't have a build script, you can do this: node -e 'import("barely-a-dev-server").then(s => s.barelyServe({entryRoot: "src"}))'
• No automatic URL opening, no live refresh.

These are mostly because it would make the codebase significantly larger to support them properly.