test(reflect): add closure call cases

Author: cpunion

_demo/go/reflectfunc/reflectfunc.go

@@ -54,6 +54,32 @@ func main() {
 	if len(out) != 1 || out[0].Int() != 15 {
 		panic(fmt.Sprintf("reflect closure call failed: got %v", out))
 	}
+
+	// More complex closure calls: multi-args / multi-returns with free vars.
+	base := 7
+	scale := 3
+	mix := func(a, b int, tag string) (int, string) {
+		return base + a*scale + b, fmt.Sprintf("%s:%d", tag, base)
+	}
+	vmix := reflect.ValueOf(mix)
+	mout := vmix.Call([]reflect.Value{
+		reflect.ValueOf(2),
+		reflect.ValueOf(5),
+		reflect.ValueOf("k"),
+	})
+	if len(mout) != 2 || mout[0].Int() != 18 || mout[1].String() != "k:7" {
+		panic(fmt.Sprintf("reflect closure multi call failed: got %v", mout))
+	}
+
+	offset := 100
+	swapAdd := func(a int, b int) (int, int) {
+		return b + offset, a + offset
+	}
+	vswap := reflect.ValueOf(swapAdd)
+	sout := vswap.Call([]reflect.Value{reflect.ValueOf(1), reflect.ValueOf(9)})
+	if len(sout) != 2 || sout[0].Int() != 109 || sout[1].Int() != 101 {
+		panic(fmt.Sprintf("reflect closure swap call failed: got %v", sout))
+	}
 }
 
 type T struct {