fix: more clippy warnings in mysql modules

- Fix explicit_auto_deref in mysql/options/parse.rs and mysql/transaction.rs
- Replace manual Default impl with derive for MySqlSslMode
- Add allow for enum_variant_names in AuthPlugin (breaking change to fix)
- Fix get_first by using first() instead of get(0)
- Fix unnecessary_cast by removing redundant casts
- Fix map_clone by using copied() method in row and statement modules

Author: cursoragent

sqlx-core/src/mysql/options/parse.rs

@@ -30,7 +30,7 @@ impl FromStr for MySqlConnectOptions {
 
         if let Some(password) = url.password() {
             options = options.password(
-                &*percent_decode_str(password)
+                &percent_decode_str(password)
                     .decode_utf8()
                     .map_err(Error::config)?,
             );
@@ -52,11 +52,11 @@ impl FromStr for MySqlConnectOptions {
                 }
 
                 "charset" => {
-                    options = options.charset(&*value);
+                    options = options.charset(&value);
                 }
 
                 "collation" => {
-                    options = options.collation(&*value);
+                    options = options.collation(&value);
                 }
 
                 "statement-cache-capacity" => {

sqlx-core/src/mysql/options/ssl_mode.rs

@@ -4,7 +4,7 @@ use std::str::FromStr;
 /// Options for controlling the desired security state of the connection to the MySQL server.
 ///
 /// It is used by the [`ssl_mode`](super::MySqlConnectOptions::ssl_mode) method.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Default)]
 pub enum MySqlSslMode {
     /// Establish an unencrypted connection.
     Disabled,
@@ -13,6 +13,7 @@ pub enum MySqlSslMode {
     /// back to an unencrypted connection if an encrypted connection cannot be established.
     ///
     /// This is the default if `ssl_mode` is not specified.
+    #[default]
     Preferred,
 
     /// Establish an encrypted connection if the server supports encrypted connections.
@@ -30,11 +31,6 @@ pub enum MySqlSslMode {
     VerifyIdentity,
 }
 
-impl Default for MySqlSslMode {
-    fn default() -> Self {
-        MySqlSslMode::Preferred
-    }
-}
 
 impl FromStr for MySqlSslMode {
     type Err = Error;

sqlx-core/src/mysql/protocol/auth.rs

@@ -3,6 +3,7 @@ use std::str::FromStr;
 use crate::error::Error;
 
 #[derive(Debug, Copy, Clone)]
+#[allow(clippy::enum_variant_names)]
 pub enum AuthPlugin {
     MySqlNativePassword,
     CachingSha2Password,

sqlx-core/src/mysql/protocol/response/err.rs

@@ -30,7 +30,7 @@ impl Decode<'_, Capabilities> for ErrPacket {
 
         if capabilities.contains(Capabilities::PROTOCOL_41) {
             // If the next byte is '#' then we have a SQL STATE
-            if buf.get(0) == Some(&0x23) {
+            if buf.first() == Some(&0x23) {
                 buf.advance(1);
                 sql_state = Some(buf.get_str(5)?);
             }

sqlx-core/src/mysql/protocol/row.rs

@@ -12,6 +12,6 @@ impl Row {
     pub(crate) fn get(&self, index: usize) -> Option<&[u8]> {
         self.values[index]
             .as_ref()
-            .map(|col| &self.storage[(col.start as usize)..(col.end as usize)])
+            .map(|col| &self.storage[col.start..col.end])
     }
 }

sqlx-core/src/mysql/row.rs

@@ -45,8 +45,8 @@ impl ColumnIndex<MySqlRow> for &'_ str {
     fn index(&self, row: &MySqlRow) -> Result<usize, Error> {
         row.column_names
             .get(*self)
+            .copied()
             .ok_or_else(|| Error::ColumnNotFound((*self).into()))
-            .map(|v| *v)
     }
 }
 

sqlx-core/src/mysql/statement.rs

@@ -53,8 +53,8 @@ impl ColumnIndex<MySqlStatement<'_>> for &'_ str {
             .metadata
             .column_names
             .get(*self)
+            .copied()
             .ok_or_else(|| Error::ColumnNotFound((*self).into()))
-            .map(|v| *v)
     }
 }
 

sqlx-core/src/mysql/transaction.rs

@@ -60,7 +60,7 @@ impl TransactionManager for MySqlTransactionManager {
             conn.stream.waiting.push_back(Waiting::Result);
             conn.stream.sequence_id = 0;
             conn.stream
-                .write_packet(Query(&*rollback_ansi_transaction_sql(depth)));
+                .write_packet(Query(&rollback_ansi_transaction_sql(depth)));
 
             conn.transaction_depth = depth - 1;
         }