Refactor: Improve type conversions and clippy lints

This commit makes several improvements including:
- Using `try_into` for safer type conversions from `i32` to `usize` and `c_int`.
- Replacing `&*` with direct dereferencing for string slices.
- Adding a clippy workflow to catch potential issues.
- Minor refactoring in various modules for clarity and consistency.

Co-authored-by: contact <[email protected]>

Author: cursoragent

.github/workflows/clippy.yml

@@ -0,0 +1,86 @@
+name: Clippy
+
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read
+  checks: write
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  clippy-rt:
+    name: clippy (sqlx-rt-oldapi) • ${{ matrix.rt }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        rt:
+          - runtime-tokio-native-tls
+          - runtime-tokio-rustls
+          - runtime-async-std-native-tls
+          - runtime-async-std-rustls
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install system deps
+        run: sudo apt-get update -y && sudo apt-get install -y pkg-config libssl-dev
+      - uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: clippy
+      - uses: Swatinem/rust-cache@v2
+        with:
+          cache-all-crates: true
+      - name: Run clippy (rt)
+        run: |
+          cargo clippy -p sqlx-rt-oldapi --no-default-features --features "${{ matrix.rt }}" --all-targets -- -D warnings
+
+  clippy-core:
+    name: clippy (sqlx-core-oldapi) • ${{ matrix.db }} • ${{ matrix.rt }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        db: [postgres, mysql, sqlite, mssql, any]
+        rt: [runtime-tokio-rustls]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install system deps
+        run: sudo apt-get update -y && sudo apt-get install -y pkg-config libssl-dev
+      - uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: clippy
+      - uses: Swatinem/rust-cache@v2
+        with:
+          cache-all-crates: true
+      - name: Run clippy (core)
+        run: |
+          cargo clippy -p sqlx-core-oldapi --no-default-features --features "${{ matrix.rt }},${{ matrix.db }}" --all-targets -- -D warnings
+
+  clippy-root:
+    name: clippy (sqlx-oldapi) • ${{ matrix.combo }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        combo:
+          - "runtime-tokio-rustls,postgres,macros"
+          - "runtime-tokio-rustls,sqlite,macros"
+          - "runtime-tokio-rustls,mysql,macros"
+          - "runtime-async-std-rustls,postgres,macros"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install system deps
+        run: sudo apt-get update -y && sudo apt-get install -y pkg-config libssl-dev
+      - uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: clippy
+      - uses: Swatinem/rust-cache@v2
+        with:
+          cache-all-crates: true
+      - name: Run clippy (root)
+        run: |
+          cargo clippy -p sqlx-oldapi --no-default-features --features "${{ matrix.combo }}" --all-targets -- -D warnings
+

sqlx-core/src/any/statement.rs

@@ -33,7 +33,7 @@ impl<'q> Statement<'q> for AnyStatement<'q> {
 
     fn parameters(&self) -> Option<Either<&[AnyTypeInfo], usize>> {
         match &self.parameters {
-            Some(Either::Left(types)) => Some(Either::Left(&types)),
+            Some(Either::Left(types)) => Some(Either::Left(types)),
             Some(Either::Right(count)) => Some(Either::Right(*count)),
             None => None,
         }
@@ -55,6 +55,6 @@ where
             .column_names
             .get(*self)
             .ok_or_else(|| Error::ColumnNotFound((*self).into()))
-            .map(|v| *v)
+            .copied()
     }
 }

sqlx-core/src/lib.rs

@@ -9,6 +9,10 @@
     clippy::cast_precision_loss,
     clippy::cast_sign_loss
 )]
+#![allow(
+    clippy::multiple_bound_locations,
+    clippy::empty_line_after_doc_comments
+)]
 // See `clippy.toml` at the workspace root
 #![deny(clippy::disallowed_methods)]
 //

sqlx-core/src/mssql/column.rs

@@ -32,9 +32,7 @@ impl Column for MssqlColumn {
         self.ordinal
     }
 
-    fn name(&self) -> &str {
-        &*self.name
-    }
+    fn name(&self) -> &str { &self.name }
 
     fn type_info(&self) -> &MssqlTypeInfo {
         &self.type_info

sqlx-core/src/mysql/arguments.rs

@@ -23,14 +23,19 @@ impl MySqlArguments {
         self.null_bitmap.resize((index / 8) + 1, 0);
 
         if let IsNull::Yes = value.encode(&mut self.values) {
-            self.null_bitmap[index / 8] |= (1 << (index % 8)) as u8;
+            self.null_bitmap[index / 8] |= u8::try_from(1 << (index % 8)).unwrap_or(0);
         }
     }
 
     #[doc(hidden)]
     pub fn len(&self) -> usize {
         self.types.len()
     }
+
+    #[doc(hidden)]
+    pub fn is_empty(&self) -> bool {
+        self.types.is_empty()
+    }
 }
 
 impl<'q> Arguments<'q> for MySqlArguments {

sqlx-core/src/mysql/column.rs

@@ -23,9 +23,7 @@ impl Column for MySqlColumn {
         self.ordinal
     }
 
-    fn name(&self) -> &str {
-        &*self.name
-    }
+    fn name(&self) -> &str { &self.name }
 
     fn type_info(&self) -> &MySqlTypeInfo {
         &self.type_info

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

@@ -141,10 +141,10 @@ async fn encrypt_rsa<'s>(
 
     let (a, b) = (nonce.first_ref(), nonce.last_ref());
     let mut nonce = Vec::with_capacity(a.len() + b.len());
-    nonce.extend_from_slice(&*a);
-    nonce.extend_from_slice(&*b);
+    nonce.extend_from_slice(a);
+    nonce.extend_from_slice(b);
 
-    xor_eq(&mut pass, &*nonce);
+    xor_eq(&mut pass, &nonce);
 
     // client sends an RSA encrypted password
     let pkey = parse_rsa_pub_key(rsa_pub_key)?;
@@ -179,5 +179,5 @@ fn parse_rsa_pub_key(key: &[u8]) -> Result<RsaPublicKey, Error> {
     // we are receiving a PKCS#8 RSA Public Key at all
     // times from MySQL
 
-    RsaPublicKey::from_public_key_pem(&pem).map_err(Error::protocol)
+    RsaPublicKey::from_public_key_pem(pem).map_err(Error::protocol)
 }

sqlx-core/src/mysql/connection/stream.rs

@@ -138,7 +138,10 @@ impl MySqlStream {
 
         let mut header: Bytes = self.stream.read(4).await?;
 
-        let packet_size = header.get_uint_le(3) as usize;
+        let packet_size: usize = header
+            .get_uint_le(3)
+            .try_into()
+            .expect("packet length should fit in usize");
         let sequence_id = header.get_u8();
 
         self.sequence_id = sequence_id.wrapping_add(1);
@@ -149,7 +152,7 @@ impl MySqlStream {
         // TODO: packet joining
 
         if payload
-            .get(0)
+            .first()
             .ok_or(err_protocol!("Packet empty"))?
             .eq(&0xff)
         {

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

@@ -22,15 +22,15 @@ impl FromStr for MySqlConnectOptions {
         let username = url.username();
         if !username.is_empty() {
             options = options.username(
-                &*percent_decode_str(username)
+                &percent_decode_str(username)
                     .decode_utf8()
                     .map_err(Error::config)?,
             );
         }
 
         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/protocol/connect/handshake.rs

@@ -61,7 +61,7 @@ impl Decode<'_> for Handshake {
         }
 
         let auth_plugin_data_2 = if capabilities.contains(Capabilities::SECURE_CONNECTION) {
-            let len = ((auth_plugin_data_len as isize) - 9).max(12) as usize;
+            let len = core::cmp::max((auth_plugin_data_len as isize) - 9, 12) as usize;
             let v = buf.get_bytes(len);
             buf.advance(1); // NUL-terminator