Introducing: ESM CDN for NPM + Deno

X. — Mon, 16 Nov 2020 10:41:46 +0000

Hi, let me introduce you to esm.sh, a fast, global content delivery network (CDN) for modern(es2015+) web development that allows you to import es6 modules from a URL:

import React from 'https://esm.sh/react'

Specify version

import React from 'https://esm.sh/react@17.0.1'

Submodule

import { renderToString } from 'https://esm.sh/react-dom/server'

Deno compatibility

esm.sh will polyfill the node internal modules(fs, os, etc..) with https://deno.land/std/node to support some modules to work in Deno, like postcss:

import postcss from 'https://esm.sh/postcss'
import autoprefixer from 'https://esm.sh/autoprefixer'

const css = (await postcss([ autoprefixer]).process(`
    backdrop-filter: blur(5px);
    user-select: none;
`).async()).content

X-Typescript-Types

By default, esm.sh will response a custom HTTP header of X-TypeScript-Types when the types(dts) defined, that is useful for Deno types check (link).

More usages

Please check https://esm.sh

Open source

esm.sh is licensed under the MIT License.

https://github.com/esm-dev/esm.sh

How to `useDeno` in a React Component?

X. — Thu, 29 Oct 2020 00:26:13 +0000

Hi, let me introduce you to Aleph.js, a React Framework in Deno, inspired by Next.js.

Different with Next.js, Aleph.js don't need webpack or other bundler since it uses the ESM imports syntax during development, like Vite and snowpack. Every module only needs to be compiled once and then cached on the disk. When a module changes, Aleph.js just recompile that single module, there's no time wasted re-bundling every changes, and instant updates in the browser by HMR(Hot Module Replacement) with React Fast Refresh.

Aleph.js works in Deno, the modern and secure runtime for JavaScript and TypeScript. No package.json and node_modules directory needed, all dependencies are imported as URL and managed by Aleph.js:

import React from "https://esm.sh/react"
import Logo from "../components/logo.tsx"

export default function Page() {
    return (
      <div>
        <Logo />
        <h1>Hello World!</h1>
      </div>
    )
}

Features

Zero Config
Typescript in Deno
ES Module Ready
Import Maps
HMR with Fast Refresh
File-system Routing
Markdown Page
Built-in CSS(Less) Support
SSR/SSG
Plugins

Why Create It?

Well, as a full-stack developer and a user of Next.js, I use React in almost all of my projects and feel good with Vercel.

But there are still some defects, I would call it, let me down:

Over-complicated Webpack
Dirty AMD/UMD/CommonJS
Unnecessary package.json and ts.config.json
node_modules Hells

Maybe those are not real Pain Points for us, always can find a polyfill, but we deserve the best tools to make our life more easy.

Just as vite,snowpack,esbuild,deno,swc do: explores the best developer experience.

Deno is a simple, modern and secure runtime for JavaScript and TypeScript that uses V8 and is built in Rust. ¹

run javascript(es2020)/typescript without any config
Permissions(--allow-read, --allow-write, --allow-net, etc)
Built-in high performance tools(bundler,fmt,doc,lint) written in Rust
Browser compatibility(fetch, window namespace, etc)

For me, Deno is a prefect runtime to run full-stack frameworks, so I initiated Aleph.js.

"useDeno"

Most concepts of Aleph.js are same with Next.js, but add some different features I always wish Next do.

For exemaple, In Next.js, two functions called getStaticProps and getServerSideProps are used by the pages to fetch data at build time(SSR) or on each request. This solution isolates the data and view likes different roles of the back-end and front-end.

But for me, i prefer use Hook to fetch data during SSR, just like Aleph.js do: a hook called useDeno provided that allows you fetch data at build time(SSR) in a component with Deno runtime, that's more React Style likely:

import React from "https://esm.sh/react"
import { useDeno } from "https://deno.land/x/aleph/mod.ts"

export default function Page() {
  const version = useDeno(() => {
    return Deno.version
  })

  return (
    <p>Powered by Deno v{version.deno}</p>
  )
}

or fetch data asynchronously:

import React from "https://esm.sh/react"
import { useDeno, useRouter } from "https://deno.land/x/aleph/mod.ts"

export default function Post() {
  const { params } = useRouter()
  const post = useDeno(async () => {
    return await (await fetch(`https://.../post/${params.id}`)).json()
  })

  return (
    <h1>{post.title}</h1>
  )
}

How It Works

The useDeno hook will receive a sync or async callback(the first parameter), during the build time(SSG) each callback of useDeno will be invoked and then cache the returned data, after in the browser the callbacks of useDeno will be ignored and the cached data will be used, that's it.

More usages please our documentation: https://alephjs.org/docs

Status

Aleph.js in alpha stage, not ready for production. You can check our website which built by Aleph.js, and welcome to take a shot.

Website: https://alephjs.org
Github: https://github.com/alephjs/aleph.js (Under the MIT License.)

DEV Community: X.