style(core): apply more clippy suggestions

sqlx-core/src/executor.rs

@@ -75,7 +75,6 @@ pub trait Executor<'c>: Send + Debug + Sized {
 
     /// Execute multiple queries and return the generated results as a stream
     /// from each query, in a stream.
-    #[allow(clippy::type_complexity)]
     fn fetch_many<'e, 'q: 'e, E: 'q>(
         self,
         query: E,

sqlx-core/src/lib.rs

@@ -2,6 +2,7 @@
 //! Not intended to be used directly.
 #![recursion_limit = "512"]
 #![warn(future_incompatible, rust_2018_idioms)]
+#![allow(clippy::needless_doctest_main, clippy::type_complexity)]
 //
 // Allows an API be documented as only available in some specific platforms.
 // <https://doc.rust-lang.org/unstable-book/language-features/doc-cfg.html>

sqlx-core/src/mysql/arguments.rs

@@ -31,7 +31,7 @@ impl<'q> Arguments<'q> for MySqlArguments {
         self.null_bitmap.resize((index / 8) + 1, 0);
 
         if let IsNull::Yes = value.encode(self) {
-            self.null_bitmap[index / 8] |= (1 << index % 8) as u8;
+            self.null_bitmap[index / 8] |= (1 << (index % 8)) as u8;
         }
     }
 }

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

@@ -104,6 +104,7 @@ impl MySqlConnection {
         Ok(())
     }
 
+    #[allow(clippy::needless_lifetimes)]
     async fn run<'c>(
         &'c mut self,
         query: &str,

sqlx-core/src/mysql/io/buf.rs

@@ -21,8 +21,8 @@ impl MySqlBufExt for Bytes {
     fn get_uint_lenenc(&mut self) -> u64 {
         match self.get_u8() {
             0xfc => u64::from(self.get_u16_le()),
-            0xfd => u64::from(self.get_uint_le(3)),
+            0xfd => self.get_uint_le(3),
-            0xfe => u64::from(self.get_u64_le()),
+            0xfe => self.get_u64_le(),
 
             v => u64::from(v),
         }

sqlx-core/src/mysql/options.rs

@@ -102,6 +102,12 @@ pub struct MySqlConnectOptions {
     pub(crate) ssl_ca: Option<PathBuf>,
 }
 
+impl Default for MySqlConnectOptions {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl MySqlConnectOptions {
     /// Creates a new, default set of options ready for configuration
     pub fn new() -> Self {

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

@@ -32,11 +32,11 @@ impl Decode<'_, Capabilities> for ErrPacket {
             // If the next byte is '#' then we have a SQL STATE
             if buf.get(0) == Some(&0x23) {
                 buf.advance(1);
-                sql_state = Some(buf.get_str(5)?.to_owned());
+                sql_state = Some(buf.get_str(5)?);
             }
         }
 
-        let error_message = buf.get_str(buf.len())?.to_owned();
+        let error_message = buf.get_str(buf.len())?;
 
         Ok(Self {
             error_code,

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

@@ -1,3 +1,5 @@
+#![allow(clippy::all)]
+
 use digest::Digest;
 use num_bigint::BigUint;
 use rand::{thread_rng, Rng};

sqlx-core/src/postgres/connection/describe.rs

@@ -244,7 +244,7 @@ ORDER BY attnum
 
         query_as_with::<_, (i32, Option<bool>), _>(&query, args)
             .fetch(self)
-            .zip(stream::iter(columns.into_iter().enumerate()))
+            .zip(stream::iter(columns.iter().enumerate()))
             .map(|(row, (field_idx, column))| -> Result<Column<_>, Error> {
                 let (idx, not_null) = row?;
 

sqlx-core/src/postgres/connection/mod.rs

@@ -74,14 +74,10 @@ impl PgConnection {
             loop {
                 let message = self.stream.recv().await?;
 
-                match message.format {
+                if let MessageFormat::ReadyForQuery = message.format {
-                    MessageFormat::ReadyForQuery => {
                     self.handle_ready_for_query(message)?;
                     break;
                 }
-
-                    _ => {}
-                }
             }
         }
 

sqlx-core/src/postgres/connection/sasl.rs

@@ -9,11 +9,11 @@ use rand::Rng;
 use sha2::digest::Digest;
 use sha2::Sha256;
 
-const GS2_HEADER: &'static str = "n,,";
+const GS2_HEADER: &str = "n,,";
-const CHANNEL_ATTR: &'static str = "c";
+const CHANNEL_ATTR: &str = "c";
-const USERNAME_ATTR: &'static str = "n";
+const USERNAME_ATTR: &str = "n";
-const CLIENT_PROOF_ATTR: &'static str = "p";
+const CLIENT_PROOF_ATTR: &str = "p";
-const NONCE_ATTR: &'static str = "r";
+const NONCE_ATTR: &str = "r";
 
 pub(crate) async fn authenticate(
     stream: &mut PgStream,

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

@@ -77,7 +77,7 @@ impl PgStream {
 
         let contents = self.inner.read(size).await?;
 
-        return Ok(Message { format, contents });
+        Ok(Message { format, contents })
     }
 
     // Get the next message from the server

sqlx-core/src/postgres/listener.rs

@@ -115,7 +115,7 @@ impl PgListener {
 
     #[inline]
     async fn connect_if_needed(&mut self) -> Result<(), Error> {
-        if let None = self.connection {
+        if self.connection.is_none() {
             let mut connection = self.pool.acquire().await?;
             connection.stream.notifications = self.buffer_tx.take();
 

sqlx-core/src/postgres/message/authentication.rs

@@ -179,13 +179,9 @@ impl Decode<'_> for AuthenticationSaslFinal {
             let key = item[0];
             let value = &item[2..];
 
-            match key {
+            if let b'v' = key {
-                b'v' => {
                 verifier = base64::decode(value).map_err(Error::protocol)?;
             }
-
-                _ => {}
-            }
         }
 
         Ok(Self { verifier })

sqlx-core/src/postgres/options.rs

@@ -116,6 +116,12 @@ pub struct PgConnectOptions {
     pub(crate) ssl_root_cert: Option<PathBuf>,
 }
 
+impl Default for PgConnectOptions {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl PgConnectOptions {
     /// Creates a new, default set of options ready for configuration.
     ///
@@ -289,16 +295,14 @@ fn default_host(port: u16) -> String {
         "/tmp",                // Default
     ];
 
-    'outer: loop {
     for candidate in &candidates {
         if Path::new(candidate).join(&socket).exists() {
-                break 'outer candidate.to_string();
+            return candidate.to_string();
         }
     }
 
     // fallback to localhost if no socket was found
-        break "localhost".to_owned();
+    "localhost".to_owned()
-    }
 }
 
 impl FromStr for PgConnectOptions {

sqlx-core/src/postgres/type_info.rs

@@ -603,7 +603,7 @@ impl TypeInfo for PgTypeInfo {}
 
 impl PartialEq<PgCustomType> for PgCustomType {
     fn eq(&self, other: &PgCustomType) -> bool {
-        return other.oid == self.oid;
+        other.oid == self.oid
     }
 }
 

sqlx-core/src/postgres/types/bytes.rs

@@ -59,7 +59,7 @@ impl<'r> Decode<'r, Postgres> for &'r [u8] {
         match value.format() {
             PgValueFormat::Binary => value.as_bytes(),
             PgValueFormat::Text => {
-                return Err("unsupported decode to `&[u8]` of BYTEA in a simple query; use a prepared query or decode to `Vec<u8>`".into());
+                Err("unsupported decode to `&[u8]` of BYTEA in a simple query; use a prepared query or decode to `Vec<u8>`".into())
             }
         }
     }

sqlx-core/src/postgres/types/ipnetwork.rs

@@ -128,6 +128,6 @@ impl Decode<'_, Postgres> for IpNetwork {
             }
         }
 
-        return Err(format!("invalid data received when expecting an INET").into());
+        Err("invalid data received when expecting an INET".into())
     }
 }

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

@@ -32,7 +32,7 @@ impl Encode<'_, Postgres> for &'_ str {
 
 impl Encode<'_, Postgres> for String {
     fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> IsNull {
-        <&str as Encode<Postgres>>::encode(&mut &**self, buf)
+        <&str as Encode<Postgres>>::encode(&**self, buf)
     }
 }
 

sqlx-core/src/query.rs

@@ -302,7 +302,7 @@ where
 
 /// Make a SQL query.
 #[inline]
-pub fn query<'q, DB>(sql: &'q str) -> Query<'q, DB, <DB as HasArguments<'q>>::Arguments>
+pub fn query<DB>(sql: &str) -> Query<'_, DB, <DB as HasArguments<'_>>::Arguments>
 where
     DB: Database,
 {

sqlx-core/src/sqlite/connection/executor.rs

@@ -191,7 +191,7 @@ impl<'c> Executor<'c> for &'c mut SqliteConnection {
                 columns.reserve(num_columns);
 
                 for i in 0..num_columns {
-                    let name = statement.column_name(i).to_owned().into();
+                    let name = statement.column_name(i).to_owned();
                     let type_info = statement.column_decltype(i);
                     let not_null = statement.column_not_null(i)?;
 

sqlx-core/src/sqlite/options.rs

@@ -12,6 +12,12 @@ pub struct SqliteConnectOptions {
     pub(crate) in_memory: bool,
 }
 
+impl Default for SqliteConnectOptions {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl SqliteConnectOptions {
     pub fn new() -> Self {
         Self {