support larger numeric values using i128; add boundary tests for MONEY and SMALLMONEY types

Author: lovasoa

sqlx-core/src/mssql/types/decimal.rs

@@ -73,6 +73,19 @@ impl Decode<'_, Mssql> for Decimal {
 
 fn decode_numeric(bytes: &[u8], _precision: u8, scale: u8) -> Result<Decimal, BoxDynError> {
     let (sign, numerator) = decode_numeric_bytes(bytes)?;
-    let small_num: i64 = sign as i64 * i64::try_from(numerator)?;
-    Ok(Decimal::new(small_num, u32::from(scale)))
+    
+    // Try to convert to i128 to handle larger values than i64
+    let signed_numerator = match i128::try_from(numerator) {
+        Ok(val) => sign as i128 * val,
+        Err(_) => {
+            return Err(err_protocol!(
+                "numeric value {} is too large to be represented as an i128 (max: {}, min: {})",
+                numerator,
+                i128::MAX,
+                i128::MIN
+            ).into());
+        }
+    };
+    
+    Ok(Decimal::from_i128_with_scale(signed_numerator, u32::from(scale)))
 }

tests/mssql/types.rs

@@ -215,17 +215,43 @@ mod decimal {
             == Decimal::from_str_exact("0.01234567890123456789").unwrap(),
         "CAST('-12345678901234' AS DECIMAL(28,5))"
             == Decimal::from_str_exact("-12345678901234").unwrap(),
-        "CAST('-1234567890.1234' AS MONEY)" == Decimal::from_str_exact("-1234567890.1234").unwrap(),
-        "CAST('-123456.1234' AS SMALLMONEY)" == Decimal::from_str_exact("-123456.1234").unwrap(),
+    ));
+
+    test_type!(money_boundary_tests<Decimal>(
+        Mssql,
         "CAST('922337203685477.5807' AS MONEY)" == Decimal::from_str_exact("922337203685477.5807").unwrap(),
         "CAST('-922337203685477.5808' AS MONEY)" == Decimal::from_str_exact("-922337203685477.5808").unwrap(),
+        "CAST('922337203685477.5806' AS MONEY)" == Decimal::from_str_exact("922337203685477.5806").unwrap(),
+        "CAST('-922337203685477.5807' AS MONEY)" == Decimal::from_str_exact("-922337203685477.5807").unwrap(),
+        "CAST('922337203685477.0000' AS MONEY)" == Decimal::from_str_exact("922337203685477.0000").unwrap(),
+        "CAST('-922337203685477.0000' AS MONEY)" == Decimal::from_str_exact("-922337203685477.0000").unwrap(),
+    ));
+
+    test_type!(smallmoney_boundary_tests<Decimal>(
+        Mssql,
         "CAST('214748.3647' AS SMALLMONEY)" == Decimal::from_str_exact("214748.3647").unwrap(),
         "CAST('-214748.3648' AS SMALLMONEY)" == Decimal::from_str_exact("-214748.3648").unwrap(),
+        "CAST('214748.3646' AS SMALLMONEY)" == Decimal::from_str_exact("214748.3646").unwrap(),
+        "CAST('-214748.3647' AS SMALLMONEY)" == Decimal::from_str_exact("-214748.3647").unwrap(),
+        "CAST('214748.0000' AS SMALLMONEY)" == Decimal::from_str_exact("214748.0000").unwrap(),
+        "CAST('-214748.0000' AS SMALLMONEY)" == Decimal::from_str_exact("-214748.0000").unwrap(),
+    ));
+
+    test_type!(money_precision_tests<Decimal>(
+        Mssql,
+        "CAST('0.0000' AS MONEY)" == Decimal::from_str_exact("0.0000").unwrap(),
         "CAST('0.0001' AS MONEY)" == Decimal::from_str_exact("0.0001").unwrap(),
         "CAST('-0.0001' AS MONEY)" == Decimal::from_str_exact("-0.0001").unwrap(),
-        "CAST('0.0000' AS MONEY)" == Decimal::from_str_exact("0.0000").unwrap(),
-        "CAST('999999999999999.9999' AS MONEY)" == Decimal::from_str_exact("999999999999999.9999").unwrap(),
-        "CAST('-999999999999999.9999' AS MONEY)" == Decimal::from_str_exact("-999999999999999.9999").unwrap(),
+        "CAST('0.9999' AS MONEY)" == Decimal::from_str_exact("0.9999").unwrap(),
+        "CAST('-0.9999' AS MONEY)" == Decimal::from_str_exact("-0.9999").unwrap(),
+        "CAST('1.0000' AS MONEY)" == Decimal::from_str_exact("1.0000").unwrap(),
+        "CAST('-1.0000' AS MONEY)" == Decimal::from_str_exact("-1.0000").unwrap(),
+        "CAST('2.15' AS MONEY)" == Decimal::from_str_exact("2.15").unwrap(),
+        "CAST('214748.3647' AS SMALLMONEY)" == Decimal::from_str_exact("214748.3647").unwrap(),
+        "CAST('922337203685477.5807' AS MONEY)" == Decimal::from_str_exact("922337203685477.5807").unwrap(),
+        "CAST('-922337203685477.5808' AS MONEY)" == Decimal::from_str_exact("-922337203685477.5808").unwrap(),
+        "CAST('214748.3647' AS SMALLMONEY)" == Decimal::from_str_exact("214748.3647").unwrap(),
+        "CAST('-214748.3648' AS SMALLMONEY)" == Decimal::from_str_exact("-214748.3648").unwrap(),
     ));
 }