From 9faa609930fdff016d0ca5ce8dafed9198531c30 Mon Sep 17 00:00:00 2001
From: Chan Wen Xu <lutherchanpublic@gmail.com>
Date: Sun, 21 Mar 2021 21:38:39 +0800
Subject: [PATCH] fix: Use function wrapper provided by JS

---
 wasm/function.go |  4 ++--
 wasm/wasm.go     | 17 ++++++++++++++---
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/wasm/function.go b/wasm/function.go
index a509c85..5b29f35 100644
--- a/wasm/function.go
+++ b/wasm/function.go
@@ -27,7 +27,7 @@ func toJSFunc(x reflect.Value) js.Value {
 		hasError = funcType.Out(funcType.NumOut()-1) == errorType
 	}
 
-	return js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	return funcWrapper.Invoke(js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 		in, err := conformJSValueToType(funcType, this, args)
 		if err != nil {
 			return ToJSValue(goThrowable{
@@ -52,7 +52,7 @@ func toJSFunc(x reflect.Value) js.Value {
 		return ToJSValue(goThrowable{
 			Result: returnValue(out[:len(out)-1]),
 		})
-	}).JSValue()
+	}))
 }
 
 var jsValueType = reflect.TypeOf(js.Value{})
diff --git a/wasm/wasm.go b/wasm/wasm.go
index 56d94c2..3e9f8e4 100644
--- a/wasm/wasm.go
+++ b/wasm/wasm.go
@@ -1,12 +1,18 @@
 package wasm
 
+import "syscall/js"
+
 // Magic values to communicate with the JS library.
 const (
-	globalIdent = "__go_wasm__"
-	readyHint   = "__ready__"
+	globalIdent     = "__go_wasm__"
+	readyHint       = "__ready__"
+	funcWrapperName = "__wrapper__"
 )
 
-var bridge Object
+var (
+	bridge      Object
+	funcWrapper js.Value
+)
 
 func init() {
 	bridgeJS, err := Global().Get(globalIdent)
@@ -18,6 +24,11 @@ func init() {
 	if err != nil {
 		panic("JS wrapper " + globalIdent + " is not an object")
 	}
+
+	funcWrapper, err = bridge.Get(funcWrapperName)
+	if err != nil {
+		panic("JS wrapper " + globalIdent + "." + funcWrapperName + " not found")
+	}
 }
 
 // Ready notifies the JS bridge that the WASM is ready.