Add workaround for the new path of wasm_exec.js

.vscode/launch.json

@@ -9,7 +9,7 @@
             "type": "go",
             "request": "launch",
             "mode": "auto",
-            "program": "${workspaceFolder}/scripts/dev-server/devserver.go",
+            "program": "${workspaceFolder}/scripts/dev-server/",
             "env": {
                 "GOOS": "windows",
                 "GOARCH": "amd64"

scripts/dev-server/devserver.go

@@ -16,11 +16,14 @@ func main() {
 	simplehttp.DefaultStaticData["Title"] = "D3vugu-components examples"
 	simplehttp.DefaultStaticData["CSSFiles"] = []string{"/static/css/d3c-theme-base.css"}
 
+	var wasmHandler WASMExecHandler
+
 	wd, _ := os.Getwd()
 	uiDir := filepath.Join(wd)
 	l := ":8875"
 	log.Printf("Starting HTTP Server at %q", l)
 	h := simplehttp.New(uiDir, true)
+	http.Handle("/wasm_exec.js", &wasmHandler) // A hack to circumvent the old hardcoded path in simplehttp. TODO: Seek alternative to the simplehttp dev server
 	http.Handle("/", h)
 	http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir(filepath.Join(uiDir, "static")))))
 

scripts/dev-server/wasm-exec-handler.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"bytes"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+)
+
+type WASMExecHandler struct {
+	wasmExecJsOnce    sync.Once
+	wasmExecJsContent []byte
+	wasmExecJsTs      time.Time
+}
+
+func (h *WASMExecHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	b, err := exec.Command("go", "env", "GOROOT").CombinedOutput()
+	if err != nil {
+		http.Error(w, "failed to run `go env GOROOT`: "+err.Error(), 500)
+		return
+	}
+
+	h.wasmExecJsOnce.Do(func() {
+		h.wasmExecJsContent, err = os.ReadFile(filepath.Join(strings.TrimSpace(string(b)), "lib/wasm/wasm_exec.js"))
+		if err != nil {
+			http.Error(w, "failed to run `go env GOROOT`: "+err.Error(), 500)
+			return
+		}
+		h.wasmExecJsTs = time.Now() // hack but whatever for now
+	})
+
+	if len(h.wasmExecJsContent) == 0 {
+		http.Error(w, "failed to read wasm_exec.js from local Go environment", 500)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/javascript")
+	http.ServeContent(w, r, "/wasm_exec.js", h.wasmExecJsTs, bytes.NewReader(h.wasmExecJsContent))
+}