svelte-language-server-web

Svelte language server within a web worker.

Based on/inspired by: https://github.com/asafamr/monaco-svelte/

Warning: this is highly experimental, and is nearly production ready!

Features

• Uses latest packages for typescript, svelte, svelte-preprocess, etc.
• Editor-agnostic, use with Monaco, VSCode Web, CodeMirror...
• Supports SvelteKit
  • also supports SvelteKit's auto-generated type definitions for your routes and endpoints!
• Works fully like you'd expect!
• Path aliases ($lib/, @/, or anything defined in tsconfig.json/jsconfig.json)
• Automatic type acquisition (ATA)
  • You must send a package.json file (as an object) to the Worker for this feature to work.
• TypeScript Language Server (for .js/.ts file intellisense)

How it works

The core of all of this is the module_shims directory. Therein lies most of the custom code, such as the fs module which is used and injected wherever fs is imported. Essentially this repo emulates Node.js wherever it can, otherwise it will just do a barebones shim so that 'it works'.

However, good news is, there shouldn't be many pain points. As far as I've tested, all functionality works just like in the official Svelte Language Server!

Demo

Need convinced? Try it out here!

(demo uses CodeMirror 6, paired with https://github.com/FurqanSoftware/codemirror-languageserver)

Usage

Creating the Svelte Language Server worker:

// /worker.ts
import { SvelteLanguageWorker } from "svelte-language-server-web/svelteWorker";

export default SvelteLanguageWorker();

Creating the TypeScript Language Server worker:

// /tsWorker.ts
import { TypeScriptWorker } from "svelte-language-server-web/tsWorker";

export default TypeScriptWorker();

Using the worker (CodeMirror 6):

import { WorkerRPC } from "svelte-language-server-web";

const files = {
  "/package.json": "...", // package.json as a string
  "/tsconfig.json": "...", // tsconfig.json as a string
  "/src/App.svelte": "...", // Svelte Component as a string
  // .. rest of your files
};

// setup the svelte worker
const svelteWorker = new Worker(new URL("./worker.ts", import.meta.url), {
  type: "module",
});

// setup the typescript worker
const tsWorker = new Worker(new URL("./tsWorker.ts", import.meta.url), {
  type: "module",
});

const svelteLanguageServer = new WorkerRPC(svelteWorker, {
  rootUri: null,
  workspaceFolders: null,
  // full options can be found here: https://github.com/FurqanSoftware/codemirror-languageserver/blob/master/src/index.ts#L466-L476
});

const tsLanguageServer = new WorkerRPC(tsWorker, {
  rootUri: null,
  workspaceFolders: null,
});

await Promise.all([
  /**
   * fetch the type definitions for your dependencies
   * (can be called at any time to fetch type definitions for packages on-demand)
   */
  svelteLanguageServer.fetchTypes(files["/package.json"]),
  tsLanguageServer.fetchTypes(files["/package.json"]),

  /**
   * add your project's files
   * (can be called at any time to add files on-demand)
   */
  svelteLanguageServer.addFiles(files),
  tsLanguageServer.addFiles(files),

  // setup and finish setup
  svelteLanguageServer.setup(files),
  tsLanguageServer.setup(files),
]);

// create the EditorState per document
const state = EditorState.create({
  doc: files["/src/App.svelte"],
  extensions: [
    languageServerWithTransport({
      transport: svelteLanguageServer,
      documentUri: "file:///src/App.svelte", // documentUri must start with `file:///`
      languageId: "svelte",
      workspaceFolders: null,
      rootUri: "file:///",
      allowHTMLContent: true,
      autoClose: false,
      client: svelteLanguageServer.client(),
    }),
  ],
});

// Create the editor with basic setup and Svelte + TypeScript language server integration
const editor = new EditorView({
  state,
  parent: document.getElementById("editor")!,
  extensions: [],
});

More complete examples of usage can be found in /examples within the repository.

Supporting Svelte

(from: https://github.com/sveltejs/language-tools/blob/master/README.md) Be sure to support their great work!

Svelte is an MIT-licensed open source project with its ongoing development made possible entirely by the support of awesome volunteers. If you'd like to support their efforts, please consider:

• Becoming a backer on Open Collective.

Funds donated via Open Collective will be used for compensating expenses related to Svelte's development such as hosting costs. If sufficient donations are received, funds may also be used to support Svelte's development more directly.

License

MIT

Credits

• The Svelte maintainers for their interest in this project, as well as their support
• sveltejs/language-tools for the original code this repo is based on
• asafamr/monaco-svelte for originally inspiring this repo
• asafamr/svelte-vscode-web for originally inspiring this repo, and for originally doing the heavy lifting with the config, as well as certain patches