Strict type checking in ToSql

cc #14

Author: sfackler

src/lib.rs

@@ -263,16 +263,16 @@ impl PostgresConnection {
 
         let types = [];
         self.write_messages([
-                &Parse {
-                    name: stmt_name,
-                    query: query,
-                    param_types: types
-                },
-                &Describe {
-                    variant: 'S' as u8,
-                    name: stmt_name
-                },
-                &Sync]);
+            &Parse {
+                name: stmt_name,
+                query: query,
+                param_types: types
+            },
+            &Describe {
+                variant: 'S' as u8,
+                name: stmt_name
+            },
+            &Sync]);
 
         match_read_message!(self, {
             ParseComplete => (),
@@ -429,6 +429,10 @@ impl<'self> Drop for PostgresStatement<'self> {
 }
 
 impl<'self> PostgresStatement<'self> {
+    pub fn num_params(&self) -> uint {
+        self.param_types.len()
+    }
+
     fn bind(&self, portal_name: &str, params: &[&ToSql])
             -> Option<PostgresDbError> {
         let mut formats = ~[];

src/test.rs

@@ -44,7 +44,7 @@ fn test_query() {
     do test_in_transaction |trans| {
         trans.update("CREATE TABLE foo (id BIGINT PRIMARY KEY)", []);
         trans.update("INSERT INTO foo (id) VALUES ($1), ($2)",
-                     [&1 as &ToSql, &2 as &ToSql]);
+                     [&1i64 as &ToSql, &2i64 as &ToSql]);
         let stmt = trans.prepare("SELECT * from foo ORDER BY id");
         let result = stmt.query([]);
 
@@ -118,12 +118,12 @@ fn test_binary_bool_params() {
 
 #[test]
 fn test_binary_i16_params() {
-    test_param_type("SMALLINT", [Some(0x0011), Some(-0x0011), None]);
+    test_param_type("SMALLINT", [Some(0x0011i16), Some(-0x0011i16), None]);
 }
 
 #[test]
 fn test_binary_i32_params() {
-    test_param_type("INT", [Some(0x00112233), Some(-0x00112233), None]);
+    test_param_type("INT", [Some(0x00112233i32), Some(-0x00112233i32), None]);
 }
 
 #[test]
@@ -184,8 +184,19 @@ fn test_wrong_num_params() {
             Err(PostgresDbError { code: ~"08P01", _ }) => (),
             resp => fail!("Unexpected response: %?", resp)
         }
+    }
+}
 
-        trans.set_rollback();
+#[test]
+#[should_fail]
+fn test_wrong_param_type() {
+    do test_in_transaction |trans| {
+        trans.update("CREATE TABLE foo (
+                        id SERIAL PRIMARY KEY,
+                        val BOOL
+                      )", []);
+        trans.try_update("INSERT INTO foo (val) VALUES ($1)",
+                         [&1i32 as &ToSql]);
     }
 }
 

src/types.rs

@@ -14,6 +14,7 @@ static INT2OID: Oid = 21;
 static INT4OID: Oid = 23;
 static FLOAT4OID: Oid = 700;
 static FLOAT8OID: Oid = 701;
+static VARCHAROID: Oid = 1043;
 
 pub enum Format {
     Text = 0,
@@ -137,23 +138,24 @@ pub trait ToSql {
     fn to_sql(&self, ty: Oid) -> (Format, Option<~[u8]>);
 }
 
-macro_rules! to_str_impl(
-    ($t:ty) => (
-        impl ToSql for $t {
-            fn to_sql(&self, _ty: Oid) -> (Format, Option<~[u8]>) {
-                (Text, Some(self.to_str().into_bytes()))
-            }
+macro_rules! check_oid(
+    ($expected:ident, $actual:ident) => (
+        if $expected != $actual {
+            fail!("Attempted to bind an invalid type. Expected Oid %? but got \
+                   Oid %?", $expected, $actual);
         }
     )
 )
 
 macro_rules! to_option_impl(
-    ($t:ty) => (
+    ($oid:ident, $t:ty) => (
         impl ToSql for Option<$t> {
             fn to_sql(&self, ty: Oid) -> (Format, Option<~[u8]>) {
+                check_oid!($oid, ty)
+
                 match *self {
                     None => (Text, None),
-                    Some(val) => val.to_sql(ty)
+                    Some(ref val) => val.to_sql(ty)
                 }
             }
         }
@@ -164,74 +166,47 @@ macro_rules! to_conversions_impl(
     ($oid:ident, $t:ty, $f:ident) => (
         impl ToSql for $t {
             fn to_sql(&self, ty: Oid) -> (Format, Option<~[u8]>) {
-                if ty == $oid {
-                    let mut writer = MemWriter::new();
-                    writer.$f(*self);
-                    (Binary, Some(writer.inner()))
-                } else {
-                    (Text, Some(self.to_str().into_bytes()))
-                }
+                check_oid!($oid, ty)
+
+                let mut writer = MemWriter::new();
+                writer.$f(*self);
+                (Binary, Some(writer.inner()))
             }
         }
     )
 )
 
 impl ToSql for bool {
     fn to_sql(&self, ty: Oid) -> (Format, Option<~[u8]>) {
-        if ty == BOOLOID {
-            (Binary, Some(~[*self as u8]))
-        } else {
-            (Text, Some(self.to_str().into_bytes()))
-        }
+        check_oid!(BOOLOID, ty)
+        (Binary, Some(~[*self as u8]))
     }
 }
-to_option_impl!(bool)
+to_option_impl!(BOOLOID, bool)
 
 to_conversions_impl!(INT2OID, i16, write_be_i16_)
-to_option_impl!(i16)
+to_option_impl!(INT2OID, i16)
 to_conversions_impl!(INT4OID, i32, write_be_i32_)
-to_option_impl!(i32)
+to_option_impl!(INT4OID, i32)
 to_conversions_impl!(INT8OID, i64, write_be_i64_)
-to_option_impl!(i64)
+to_option_impl!(INT8OID, i64)
 to_conversions_impl!(FLOAT4OID, f32, write_be_f32_)
-to_option_impl!(f32)
+to_option_impl!(FLOAT4OID, f32)
 to_conversions_impl!(FLOAT8OID, f64, write_be_f64_)
-to_option_impl!(f64)
-
-to_str_impl!(int)
-to_option_impl!(int)
-to_str_impl!(i8)
-to_option_impl!(i8)
-to_str_impl!(uint)
-to_option_impl!(uint)
-to_str_impl!(u8)
-to_option_impl!(u8)
-to_str_impl!(u16)
-to_option_impl!(u16)
-to_str_impl!(u32)
-to_option_impl!(u32)
-to_str_impl!(u64)
-to_option_impl!(u64)
-to_str_impl!(float)
-to_option_impl!(float)
+to_option_impl!(FLOAT8OID, f64)
 
 impl<'self> ToSql for &'self str {
-    fn to_sql(&self, _ty: Oid) -> (Format, Option<~[u8]>) {
+    fn to_sql(&self, ty: Oid) -> (Format, Option<~[u8]>) {
+        check_oid!(VARCHAROID, ty)
         (Text, Some(self.as_bytes().to_owned()))
     }
 }
 
-impl ToSql for Option<~str> {
-    fn to_sql(&self, ty: Oid) -> (Format, Option<~[u8]>) {
-        match *self {
-            None => (Text, None),
-            Some(ref val) => val.to_sql(ty)
-        }
-    }
-}
+to_option_impl!(VARCHAROID, ~str)
 
 impl<'self> ToSql for Option<&'self str> {
     fn to_sql(&self, ty: Oid) -> (Format, Option<~[u8]>) {
+        check_oid!(VARCHAROID, ty)
         match *self {
             None => (Text, None),
             Some(val) => val.to_sql(ty)