disallow wrapping conversions for mssql

Author: lovasoa

sqlx-core/src/lib.rs

@@ -3,6 +3,7 @@
 #![recursion_limit = "512"]
 #![warn(future_incompatible, rust_2018_idioms)]
 #![allow(clippy::needless_doctest_main, clippy::type_complexity, dead_code)]
+#![deny(cast_possible_truncation, cast_possible_wrap, cast_precision_loss, cast_sign_loss)]
 // See `clippy.toml` at the workspace root
 #![deny(clippy::disallowed_methods)]
 //

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

@@ -79,6 +79,8 @@ impl Decode<'_, Mssql> for f64 {
         }
     }
 }
+
+#[allow(clippy::cast_precision_loss)]
 fn decode_numeric(bytes: &[u8], _precision: u8, mut scale: u8) -> Result<f64, BoxDynError> {
     let sign = if bytes[0] == 0 { -1. } else { 1. };
     let rest = &bytes[1..];

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

@@ -27,7 +27,7 @@ impl Encode<'_, Mssql> for i8 {
 
 impl Decode<'_, Mssql> for i8 {
     fn decode(value: MssqlValueRef<'_>) -> Result<Self, BoxDynError> {
-        Ok(value.as_bytes()?[0] as i8)
+        Ok(i8::from_le_bytes(value.as_bytes()?[0..1].try_into()?))
     }
 }
 

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

@@ -38,9 +38,11 @@ impl Type<Mssql> for String {
 impl Encode<'_, Mssql> for &'_ str {
     fn produces(&self) -> Option<MssqlTypeInfo> {
         let len = self.len().checked_mul(2)?;
-        let size = if len <= 4000 {
+        let size = if len <= 2 {
+            2
+        } else if len <= 4000 {
             // an empty string needs to be encoded as `nvarchar(2)`
-            (len as u32).max(2)
+            u32::try_from(len).unwrap()
         } else {
             0xFF_FF
         };

src/macros/mod.rs

@@ -49,12 +49,12 @@
 ///       below.
 ///
 /// * The query must be a string literal, or concatenation of string literals using `+` (useful
-/// for queries generated by macro), or else it cannot be introspected (and thus cannot be dynamic
-/// or the result of another macro).
+///   for queries generated by macro), or else it cannot be introspected (and thus cannot be dynamic
+///   or the result of another macro).
 ///
 /// * The `QueryAs` instance will be bound to the same database type as `query!()` was compiled
-/// against (e.g. you cannot build against a Postgres database and then run the query against
-/// a MySQL database).
+///   against (e.g. you cannot build against a Postgres database and then run the query against
+///   a MySQL database).
 ///
 ///     * The schema of the database URL (e.g. `postgres://` or `mysql://`) will be used to
 ///       determine the database type.
@@ -415,7 +415,7 @@ macro_rules! query_file_unchecked (
 /// * The query must output at least one column.
 /// * The column names of the query must match the field names of the struct.
 /// * The field types must be the Rust equivalent of their SQL counterparts; see the corresponding
-/// module for your database for mappings:
+///   module for your database for mappings:
 ///     * Postgres: [crate::postgres::types]
 ///     * MySQL: [crate::mysql::types]
 ///     * SQLite: [crate::sqlite::types]

tests/mssql/macros.rs

@@ -1,3 +1,4 @@
+#[allow(unused_imports)]
 use sqlx_oldapi as sqlx;
 use sqlx_oldapi::Mssql;
 use sqlx_test::new;

tests/mssql/types.rs

@@ -1,3 +1,5 @@
+use core::f32;
+
 use sqlx_oldapi::mssql::Mssql;
 use sqlx_test::test_type;
 
@@ -43,7 +45,7 @@ test_type!(i64(Mssql, "CAST(32324324432 AS BIGINT)" == 32324324432_i64));
 
 test_type!(f32(
     Mssql,
-    "CAST(3.1410000324249268 AS REAL)" == 3.141f32 as f64 as f32
+    "CAST(3.14159265358979323846264338327950288 AS REAL)" == f32::consts::PI
 ));
 
 test_type!(f64(
@@ -70,7 +72,7 @@ test_type!(numeric<f64>(Mssql,
     "CAST(1.0000000000000001 AS NUMERIC(18,16))" == 1.0000000000000001_f64,
     "CAST(0.99999999999999 AS NUMERIC(18,14))" == 0.99999999999999_f64,
     "CAST(2.00000000000001 AS NUMERIC(18,14))" == 2.00000000000001_f64,
-    "CAST(333.33333333333333 AS NUMERIC(18,14))" == 333.33333333333333_f64,
+    "CAST(333.33333333333333 AS NUMERIC(18,14))" == 333.333_333_333_333_3_f64,
     "CAST(0.14285714285714 AS NUMERIC(18,14))" == 0.14285714285714_f64,
     "CAST(9999999.99999999 AS NUMERIC(16,8))" == 9999999.99999999_f64, // Close to the precision limit
     "CAST(9007199254740992 AS NUMERIC(16,0))" == 9007199254740992_f64,    // 2^53, largest integer that can be exactly represented as a f64