add call class Constructor (#351)

quickjs_test.go

@@ -854,3 +854,34 @@ func TestModule2(t *testing.T) {
 	require.NoError(t, err)
 	require.EqualValues(t, 144, ctx.Globals().Get("result").Int32())
 }
+
+func TestClassConstructor(t *testing.T) {
+	rt := quickjs.NewRuntime()
+	defer rt.Close()
+	ctx := rt.NewContext()
+	defer ctx.Close()
+
+	ret, err := ctx.Eval(`
+		class Foo {
+			x = 0;	
+			constructor(x) {
+				this.x = x;
+			}
+		}
+		globalThis.Foo = Foo;
+	`)
+	defer ret.Free()
+	require.NoError(t, err)
+
+	Foo := ctx.Globals().Get("Foo")
+	defer Foo.Free()
+
+	fooInstance := Foo.New(ctx.Int32(10))
+	defer fooInstance.Free()
+
+	x := fooInstance.Get("x")
+	defer x.Free()
+
+	require.EqualValues(t, 10, x.Int32())
+
+}

value.go

@@ -254,6 +254,27 @@ func (v Value) Call(fname string, args ...Value) Value {
 	return Value{ctx: v.ctx, ref: C.JS_Call(v.ctx.ref, fn.ref, v.ref, C.int(len(cargs)), &cargs[0])}
 }
 
+// Call Class Constructor
+func (v Value) New(args ...Value) Value {
+	return v.CallConstructor(args...)
+}
+
+// Call calls the constructor with the given arguments.
+func (v Value) CallConstructor(args ...Value) Value {
+	if !v.IsConstructor() {
+		return v.ctx.Error(errors.New("Object not a constructor"))
+	}
+
+	cargs := []C.JSValue{}
+	for _, x := range args {
+		cargs = append(cargs, x.ref)
+	}
+	if len(cargs) == 0 {
+		return Value{ctx: v.ctx, ref: C.JS_CallConstructor(v.ctx.ref, v.ref, C.int(0), nil)}
+	}
+	return Value{ctx: v.ctx, ref: C.JS_CallConstructor(v.ctx.ref, v.ref, C.int(len(cargs)), &cargs[0])}
+}
+
 // Error returns the error value of the value.
 func (v Value) Error() error {
 	if !v.IsError() {
@@ -364,4 +385,4 @@ func (v Value) IsPromise() bool {
 	return false
 }
 
-// func (v Value) IsConstructor() bool   { return C.JS_IsConstructor(v.ctx.ref, v.ref) == 1 }
+func (v Value) IsConstructor() bool { return C.JS_IsConstructor(v.ctx.ref, v.ref) == 1 }