Require WebAssembly modules using script tag - script-wasm

script-wasm

Require WebAssembly modules using script tag

Installation

You can install script-wasm using npm :

npm install --save script-wasm

If you aren't using npm in your project, you can include scriptWasm using UMD build in the dist folder with importScripts in the serviceWorker.

Usage

Once you have installed script-wasm, supposing a CommonJS environment, in yuor serviceWorker you can import and use it in this way:

import fetchWasmScript from 'script-wasm';
// if you prefer, you can import it using a CDN instead
// self.importScripts('https://unpkg.com/[email protected]/dist/script-wasm.min.js')

self.addEventListener('fetch', (event) => {
  const newResponse = fetchWasmScript(event.request);
  // using CND:
  // const newResponse = scriptWasm.default(event.request)

  // returns null if the given request is not a .wasm from a <script> tag
  if (newResponse !== null) {
    event.respondWith(newResponse);
  }
});

In your html file:

<!--
  data-import represents the importObject passed to instantiate the module
  check out: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/instantiate
-->
<script src="/example.wasm" data-import="{ imports: { log: console.log } }"></script>

example.wasm can be a file with an associated .wat like the following, it imports log and automatically runs the function $main after the instantiation, using the start instruction:

(module
  (func $log (import "imports" "log") (param i32))

  (func $main
    (call $log
      (i32.add
        (i32.const 2)
        (i32.const 5)
      )
    )
  )

  (start $main)
)

API

// serviceWorker
fetchWasmScript(request: Request): Response?

// html
<script src="your_wasm_file.wasm" data-import="your_import_object"></script>

Change Log

This project adheres to Semantic Versioning .

Every release, along with the migration instructions, is documented on the Github Releases page.

Authors

Matteo Basso

• github/mbasso
• @teo_basso

Copyright and License

Copyright (c) 2019, Matteo Basso.

script-wasm source code is licensed under the MIT License .