test: add cases for rounding

qrbill_test.go

@@ -42,6 +42,16 @@ func TestAmountValidation(t *testing.T) {
 			wantAmount: "50.00",
 		},
 
+		{
+			amount:     "50.339",
+			wantAmount: "50.34",
+		},
+
+		{
+			amount:     "50.331",
+			wantAmount: "50.33",
+		},
+
 		{
 			amount:     "50.-",
 			wantAmount: "0.00", // result of invalid input