⚗️

docs/api.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -10,7 +9,7 @@ import (
 )
 
 func main() {
-	defer fmt.Println("api stopping...")
+	defer fmt.Println("api stopped...")
 
 	http.HandleFunc("/hello", func(res http.ResponseWriter, req *http.Request) {
 		params := make(map[string]string)
@@ -25,8 +24,5 @@ func main() {
 		}
 	})
 
-	var release = wasmhttp.Serve(nil)
+	wasmhttp.Serve(nil)
-	defer release()
-
-	<-context.Background().Done()
 }

docs/sw.js

@@ -8,4 +8,4 @@ addEventListener('activate', event => {
   event.waitUntil(clients.claim())
 })
 
-registerWasmHTTPListener('api.wasm', 'api')
+registerWasmHTTPListener('api.wasm', { base: 'api' })

serve.go

@@ -1,6 +1,7 @@
 package wasmhttp
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"strings"
@@ -10,7 +11,7 @@ import (
 )
 
 // Serve serves HTTP requests using handler or http.DefaultServeMux if handler is nil.
-func Serve(handler http.Handler) func() {
+func Serve(handler http.Handler) {
 	var h = handler
 	if h == nil {
 		h = http.DefaultServeMux
@@ -57,8 +58,27 @@ func Serve(handler http.Handler) func() {
 
 		return resPromise
 	})
+	defer cb.Release()
 
 	js.Global().Get("wasmhttp").Call("setHandler", cb)
 
-	return cb.Release
+	<-Context().Done()
+}
+
+func Context() context.Context {
+	var timeoutPromise = js.Global().Get("wasmhttp").Get("timeoutPromise")
+
+	if timeoutPromise.IsUndefined() {
+		return context.Background()
+	}
+
+	var ctx, cancel = context.WithCancel(context.Background())
+
+	go func() {
+		whutil.Promise{timeoutPromise}.Await()
+
+		cancel()
+	}()
+
+	return ctx
 }

sw.js

@@ -1,13 +1,27 @@
 importScripts('https://cdn.jsdelivr.net/gh/golang/go@go1.15.7/misc/wasm/wasm_exec.js')
 
-function registerWasmHTTPListener(wasm, base, args = []) {
+function registerWasmHTTPListener(wasm, { base, args = [], timeout = 25 } = {}) {
   let path = new URL(registration.scope).pathname
   if (base && base !== '') path = `${trimEnd(path, '/')}/${trimStart(base, '/')}`
 
+  let timeoutPromise
+  let resetTimeout
+  if (timeout) {
+    let resolveTimeout
+    timeoutPromise = new Promise(resolve => { resolveTimeout = resolve })
+    let timeoutId
+    resetTimeout = () => {
+      clearTimeout(timeoutId)
+      timeoutId = setTimeout(resolveTimeout, timeout * 1000)
+    }
+    resetTimeout()
+  }
+
   const handlerPromise = new Promise(setHandler => {
     self.wasmhttp = {
       path,
       setHandler,
+      timeoutPromise,
     }
   })
 
@@ -16,6 +30,8 @@ function registerWasmHTTPListener(wasm, base, args = []) {
   WebAssembly.instantiateStreaming(fetch(wasm), go.importObject).then(({ instance }) => go.run(instance))
 
   addEventListener('fetch', e => {
+    resetTimeout?.()
+
     const { pathname } = new URL(e.request.url)
     if (!pathname.startsWith(path)) return