优化结构

app/system/utils/paymentutil/signing_test.go

@@ -0,0 +1,12 @@
+package paymentutil
+
+import "testing"
+
+func TestWechatV2SignIsStableAndExcludesSign(t *testing.T) {
+	values := map[string]string{"b": "2", "a": "1", "sign": "old"}
+	first := WechatV2Sign(values, "secret", "MD5")
+	values["sign"] = "different"
+	if second := WechatV2Sign(values, "secret", "MD5"); first != second {
+		t.Fatalf("signature changed when sign field changed: %q != %q", first, second)
+	}
+}