feat: Provide ability to passthrough and hit network

README.md

@@ -182,7 +182,9 @@ URL string of the WebAssembly module, example: `"path/to/my-module.wasm"`.
 An optional object containing:
 
 - `base` (`string`): Base path of the server, relative to the ServiceWorker's scope.
+- `cacheName` (`string`): Name of the [Cache](https://developer.mozilla.org/en-US/docs/Web/API/Cache) to store the WebAssembly binary.
 - `args` (`string[]`): Arguments for the WebAssembly module.
+- `passthrough` (`(request: Request): boolean`): Optional callback to allow passing the request through to network.
 
 ## Contributors ✨
 

sw.js

@@ -1,4 +1,4 @@
-function registerWasmHTTPListener(wasm, { base, cacheName, args = [] } = {}) {
+function registerWasmHTTPListener(wasm, { base, cacheName, passthrough, args = [] } = {}) {
   let path = new URL(registration.scope).pathname
   if (base && base !== '') path = `${trimEnd(path, '/')}/${trimStart(base, '/')}`
 
@@ -17,6 +17,11 @@ function registerWasmHTTPListener(wasm, { base, cacheName, args = [] } = {}) {
   WebAssembly.instantiateStreaming(source, go.importObject).then(({ instance }) => go.run(instance))
 
   addEventListener('fetch', e => {
+    if (passthrough?.(e.request)) {
+        e.respondWith(fetch(e.request))
+        return;
+    }
+
     const { pathname } = new URL(e.request.url)
     if (!pathname.startsWith(path)) return