Add support for 'diesel-async' to 'db_pools'.

contrib/db_pools/lib/Cargo.toml

@@ -23,6 +23,9 @@ sqlx_postgres = ["sqlx", "sqlx/postgres"]
 sqlx_sqlite = ["sqlx", "sqlx/sqlite"]
 sqlx_mssql = ["sqlx", "sqlx/mssql"]
 sqlx_macros = ["sqlx/macros"]
+# diesel features
+diesel_postgres = ["diesel-async/postgres", "diesel-async/deadpool", "diesel", "deadpool"]
+diesel_mysql = ["diesel-async/mysql", "diesel-async/deadpool", "diesel", "deadpool"]
 # implicit features: mongodb
 
 [dependencies.rocket]
@@ -58,6 +61,16 @@ default-features = false
 features = ["tokio-runtime"]
 optional = true
 
+[dependencies.diesel-async]
+version = "0.3.1"
+default-features = false
+optional = true
+
+[dependencies.diesel]
+version = "2.1"
+default-features = false
+optional = true
+
 [dependencies.sqlx]
 version = "0.6"
 default-features = false

contrib/db_pools/lib/src/diesel.rs

@@ -0,0 +1,149 @@
+//! Re-export of [`diesel`] with prelude types overridden with `async` variants
+//! from [`diesel_async`].
+//!
+//! # Usage
+//!
+//! To use `async` `diesel` support provided here, enable the following
+//! dependencies in your `Cargo.toml`:
+//!
+//! ```toml
+//! [dependencies]
+//! rocket = "=0.5.0-rc.3"
+//! diesel = "2"
+//!
+//! [dependencies.rocket_db_pools]
+//! version = "=0.1.0-rc.3"
+//! features = ["diesel_mysql"]
+//! ```
+//!
+//! Then, import `rocket_db_pools::diesel::prelude::*` as well as the
+//! appropriate pool type and, optionally, [`QueryResult`]. To use macros or
+//! `diesel` functions, use `diesel::` directly. That is, _do not_ import
+//! `rocket_db_pools::diesel`. Doing so will, by design, cause import errors.
+//!
+//! # Example
+//!
+//! ```rust
+//! # #[macro_use] extern crate rocket;
+//! # #[cfg(feature = "diesel_mysql")] {
+//! use rocket_db_pools::{Database, Connection};
+//! use rocket_db_pools::diesel::{QueryResult, MysqlPool, prelude::*};
+//!
+//! #[derive(Database)]
+//! #[database("diesel_mysql")]
+//! struct Db(MysqlPool);
+//!
+//! #[derive(Queryable, Insertable)]
+//! #[diesel(table_name = posts)]
+//! struct Post {
+//!     id: i64,
+//!     title: String,
+//!     published: bool,
+//! }
+//!
+//! diesel::table! {
+//!     posts (id) {
+//!         id -> BigInt,
+//!         title -> Text,
+//!         published -> Bool,
+//!     }
+//! }
+//!
+//! #[get("/")]
+//! async fn list(mut db: Connection<Db>) -> QueryResult<String> {
+//!     let post_ids: Vec<i64> = posts::table
+//!         .select(posts::id)
+//!         .load(&mut db)
+//!         .await?;
+//!
+//!     Ok(format!("{post_ids:?}"))
+//! }
+//! # }
+//! ```
+
+/// The [`diesel`] prelude with `sync`-only traits replaced with their
+/// [`diesel_async`] variants.
+pub mod prelude {
+    #[doc(inline)]
+    pub use diesel::prelude::*;
+
+    #[doc(inline)]
+    pub use diesel_async::{AsyncConnection, RunQueryDsl, SaveChangesDsl};
+}
+
+#[doc(hidden)]
+pub use diesel::*;
+
+#[doc(hidden)]
+pub use diesel_async::{RunQueryDsl, SaveChangesDsl, *};
+
+#[doc(hidden)]
+#[cfg(feature = "diesel_postgres")]
+pub use diesel_async::pg;
+
+#[doc(inline)]
+pub use diesel_async::pooled_connection::deadpool::Pool;
+
+#[doc(inline)]
+#[cfg(feature = "diesel_mysql")]
+pub use diesel_async::AsyncMysqlConnection;
+
+#[doc(inline)]
+#[cfg(feature = "diesel_postgres")]
+pub use diesel_async::AsyncPgConnection;
+
+/// Alias of a `Result` with an error type of [`Debug`] for a `diesel::Error`.
+///
+/// `QueryResult` is a [`Responder`](rocket::response::Responder) when `T` (the
+/// `Ok` value) is a `Responder`. By using this alias as a route handler's
+/// return type, the `?` operator can be applied to fallible `diesel` functions
+/// in the route handler while still providing a valid `Responder` return type.
+///
+/// See the [module level docs](self#example) for a usage example.
+///
+/// [`Debug`]: rocket::response::Debug
+pub type QueryResult<T, E = rocket::response::Debug<diesel::result::Error>> = Result<T, E>;
+
+/// Type alias for an `async` pool of MySQL connections for `async` [diesel].
+///
+/// ```rust
+/// # extern crate rocket;
+/// # #[cfg(feature = "diesel_mysql")] {
+/// # use rocket::get;
+/// use rocket_db_pools::{Database, Connection};
+/// use rocket_db_pools::diesel::{MysqlPool, prelude::*};
+///
+/// #[derive(Database)]
+/// #[database("my_mysql_db_name")]
+/// struct Db(MysqlPool);
+///
+/// #[get("/")]
+/// async fn use_db(mut db: Connection<Db>) {
+///     /* .. */
+/// }
+/// # }
+/// ```
+#[cfg(feature = "diesel_mysql")]
+pub type MysqlPool = Pool<AsyncMysqlConnection>;
+
+/// Type alias for an `async` pool of Postgres connections for `async` [diesel].
+///
+/// ```rust
+/// # extern crate rocket;
+/// # #[cfg(feature = "diesel_postgres")] {
+/// # use rocket::get;
+/// use rocket_db_pools::{Database, Connection};
+/// use rocket_db_pools::diesel::{PgPool, prelude::*};
+///
+/// #[derive(Database)]
+/// #[database("my_pg_db_name")]
+/// struct Db(PgPool);
+///
+/// #[get("/")]
+/// async fn use_db(mut db: Connection<Db>) {
+///     /* .. */
+/// }
+/// # }
+/// ```
+#[cfg(feature = "diesel_postgres")]
+pub type PgPool = Pool<AsyncPgConnection>;

contrib/db_pools/lib/src/lib.rs

@@ -98,10 +98,10 @@
 //!
 //! # Supported Drivers
 //!
-//! At present, this crate supports _three_ drivers: [`deadpool`], [`sqlx`], and
+//! At present, this crate supports _four_ drivers: [`deadpool`], [`sqlx`],
-//! [`mongodb`]. Each driver may support multiple databases. Drivers have a
+//! [`mongodb`], and [`diesel`]. Each driver may support multiple databases.
-//! varying degree of support for graceful shutdown, affected by the
+//! Drivers have a varying degree of support for graceful shutdown, affected by
-//! `Type::init()` fairing on Rocket shutdown.
+//! the `Type::init()` fairing on Rocket shutdown.
 //!
 //! ## `deadpool` (v0.9)
 //!
@@ -126,10 +126,10 @@
 //! [`sqlx::MySqlPool`]: https://docs.rs/sqlx/0.6/sqlx/type.MySqlPool.html
 //! [`sqlx::SqlitePool`]: https://docs.rs/sqlx/0.6/sqlx/type.SqlitePool.html
 //! [`sqlx::MssqlPool`]: https://docs.rs/sqlx/0.6/sqlx/type.MssqlPool.html
-//! [`sqlx::PoolConnection<Postgres>`]: https://docs.rs/sqlx/0.6/sqlx/pool/struct.PoolConnection.html
+//! [`sqlx::pool::PoolConnection<Postgres>`]: https://docs.rs/sqlx/0.6/sqlx/pool/struct.PoolConnection.html
-//! [`sqlx::PoolConnection<MySql>`]: https://docs.rs/sqlx/0.6/sqlx/pool/struct.PoolConnection.html
+//! [`sqlx::pool::PoolConnection<MySql>`]: https://docs.rs/sqlx/0.6/sqlx/pool/struct.PoolConnection.html
-//! [`sqlx::PoolConnection<Sqlite>`]: https://docs.rs/sqlx/0.6/sqlx/pool/struct.PoolConnection.html
+//! [`sqlx::pool::PoolConnection<Sqlite>`]: https://docs.rs/sqlx/0.6/sqlx/pool/struct.PoolConnection.html
-//! [`sqlx::PoolConnection<Mssql>`]: https://docs.rs/sqlx/0.6/sqlx/pool/struct.PoolConnection.html
+//! [`sqlx::pool::PoolConnection<Mssql>`]: https://docs.rs/sqlx/0.6/sqlx/pool/struct.PoolConnection.html
 //!
 //! On shutdown, new connections are denied. Shutdown waits for connections to
 //! be returned.
@@ -142,6 +142,18 @@
 //!
 //! Graceful shutdown is not supported.
 //!
+//! ## `diesel` (v2)
+//!
+//! | Database | Feature           | [`Pool`] Type         | [`Connection`] Deref             |
+//! |----------|-------------------|-----------------------|----------------------------------|
+//! | Postgres | `diesel_postgres` | [`diesel::PgPool`]    | [`diesel::AsyncPgConnection`]    |
+//! | MySQL    | `diesel_mysql`    | [`diesel::MysqlPool`] | [`diesel::AsyncMysqlConnection`] | //!
+//!
+//! See [`diesel`] for usage details.
+//!
+//! On shutdown, new connections are denied. Shutdown _does not_ wait for
+//! connections to be returned.
+//!
 //! ## Enabling Additional Driver Features
 //!
 //! Only the minimal features for each driver crate are enabled by
@@ -186,7 +198,7 @@
 //!
 //! See [`Config`] for details on configuration parameters.
 //!
-//! **Note:** `deadpool` drivers do not support and thus ignore the
+//! **Note:** `deadpool` and `diesel` drivers do not support and thus ignore the
 //! `min_connections` value.
 //!
 //! ## Driver Defaults
@@ -225,11 +237,13 @@
 
 #![deny(missing_docs)]
 
+pub use rocket;
+
 /// Re-export of the `figment` crate.
 #[doc(inline)]
 pub use rocket::figment;
 
-pub use rocket;
+#[cfg(any(feature = "diesel_postgres", feature = "diesel_mysql"))] pub mod diesel;
 #[cfg(feature = "deadpool_postgres")] pub use deadpool_postgres;
 #[cfg(feature = "deadpool_redis")] pub use deadpool_redis;
 #[cfg(feature = "mongodb")] pub use mongodb;

contrib/db_pools/lib/src/pool.rs

@@ -157,6 +157,9 @@ mod deadpool_postgres {
     use deadpool::{managed::{Manager, Pool, PoolError, Object, BuildError}, Runtime};
     use super::{Duration, Error, Config, Figment};
 
+    #[cfg(any(feature = "diesel_postgres", feature = "diesel_mysql"))]
+    use diesel_async::pooled_connection::AsyncDieselConnectionManager;
+
     pub trait DeadManager: Manager + Sized + Send + Sync + 'static {
         fn new(config: &Config) -> Result<Self, Self::Error>;
     }
@@ -175,6 +178,20 @@ mod deadpool_postgres {
         }
     }
 
+    #[cfg(feature = "diesel_postgres")]
+    impl DeadManager for AsyncDieselConnectionManager<diesel_async::AsyncPgConnection> {
+        fn new(config: &Config) -> Result<Self, Self::Error> {
+            Ok(Self::new(config.url.as_str()))
+        }
+    }
+
+    #[cfg(feature = "diesel_mysql")]
+    impl DeadManager for AsyncDieselConnectionManager<diesel_async::AsyncMysqlConnection> {
+        fn new(config: &Config) -> Result<Self, Self::Error> {
+            Ok(Self::new(config.url.as_str()))
+        }
+    }
+
     #[rocket::async_trait]
     impl<M: DeadManager, C: From<Object<M>>> crate::Pool for Pool<M, C>
         where M::Type: Send, C: Send + Sync + 'static, M::Error: std::error::Error

contrib/sync_db_pools/codegen/Cargo.toml

@@ -20,4 +20,5 @@ devise = "0.4"
 [dev-dependencies]
 version_check = "0.9"
 trybuild = "1.0"
-rocket_sync_db_pools = { path = "../lib", features = ["diesel_sqlite_pool"] }
+rocket_sync_db_pools = { path = "../lib" }
+rocket = { path = "../../../core/lib" }

contrib/sync_db_pools/codegen/tests/ui-fail-nightly/database-syntax.stderr

@@ -1,57 +1,57 @@
 error: unexpected end of input, expected string literal
- --> tests/ui-fail-nightly/database-syntax.rs:6:1
+  --> tests/ui-fail-nightly/database-syntax.rs:27:1
    |
-6 | #[database]
+27 | #[database]
    | ^^^^^^^^^^^
    |
    = note: this error originates in the attribute macro `database` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: expected string literal
- --> tests/ui-fail-nightly/database-syntax.rs:9:12
+  --> tests/ui-fail-nightly/database-syntax.rs:30:12
    |
-9 | #[database(1)]
+30 | #[database(1)]
    |            ^
 
 error: expected string literal
-  --> tests/ui-fail-nightly/database-syntax.rs:12:12
+  --> tests/ui-fail-nightly/database-syntax.rs:33:12
    |
-12 | #[database(123)]
+33 | #[database(123)]
    |            ^^^
 
 error: unexpected token
-  --> tests/ui-fail-nightly/database-syntax.rs:15:20
+  --> tests/ui-fail-nightly/database-syntax.rs:36:20
    |
-15 | #[database("hello" "hi")]
+36 | #[database("hello" "hi")]
    |                    ^^^^
 
 error: `database` attribute can only be used on structs
-  --> tests/ui-fail-nightly/database-syntax.rs:19:1
+  --> tests/ui-fail-nightly/database-syntax.rs:40:1
    |
-19 | enum Foo {  }
+40 | enum Foo {  }
    | ^^^^^^^^^^^^^
 
 error: `database` attribute can only be applied to structs with exactly one unnamed field
-  --> tests/ui-fail-nightly/database-syntax.rs:22:11
+  --> tests/ui-fail-nightly/database-syntax.rs:43:11
    |
-22 | struct Bar(diesel::SqliteConnection, diesel::SqliteConnection);
+43 | struct Bar(Connection, Connection);
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: example: `struct MyDatabase(diesel::SqliteConnection);`
 
 error: `database` attribute can only be used on structs
-  --> tests/ui-fail-nightly/database-syntax.rs:25:1
+  --> tests/ui-fail-nightly/database-syntax.rs:46:1
    |
-25 | union Baz {  }
+46 | union Baz {  }
    | ^^^^^^^^^^^^^^
 
 error: `database` attribute cannot be applied to structs with generics
-  --> tests/ui-fail-nightly/database-syntax.rs:28:9
+  --> tests/ui-fail-nightly/database-syntax.rs:49:9
    |
-28 | struct E<'r>(&'r str);
+49 | struct E<'r>(&'r str);
    |         ^^^^
 
 error: `database` attribute cannot be applied to structs with generics
-  --> tests/ui-fail-nightly/database-syntax.rs:31:9
+  --> tests/ui-fail-nightly/database-syntax.rs:52:9
    |
-31 | struct F<T>(T);
+52 | struct F<T>(T);
    |         ^^^

contrib/sync_db_pools/codegen/tests/ui-fail-nightly/database-types.stderr

@@ -4,7 +4,6 @@ error[E0277]: the trait bound `Unknown: Poolable` is not satisfied
 6 | struct A(Unknown);
   |          ^^^^^^^ the trait `Poolable` is not implemented for `Unknown`
   |
-  = help: the trait `Poolable` is implemented for `SqliteConnection`
 note: required by a bound in `rocket_sync_db_pools::Connection`
  --> $WORKSPACE/contrib/sync_db_pools/lib/src/connection.rs
   |
@@ -17,7 +16,6 @@ error[E0277]: the trait bound `Vec<i32>: Poolable` is not satisfied
 9 | struct B(Vec<i32>);
   |          ^^^^^^^^ the trait `Poolable` is not implemented for `Vec<i32>`
   |
-  = help: the trait `Poolable` is implemented for `SqliteConnection`
 note: required by a bound in `rocket_sync_db_pools::Connection`
  --> $WORKSPACE/contrib/sync_db_pools/lib/src/connection.rs
   |
@@ -30,7 +28,6 @@ error[E0277]: the trait bound `Unknown: Poolable` is not satisfied
 6 | struct A(Unknown);
   |          ^^^^^^^ the trait `Poolable` is not implemented for `Unknown`
   |
-  = help: the trait `Poolable` is implemented for `SqliteConnection`
 note: required by a bound in `ConnectionPool`
  --> $WORKSPACE/contrib/sync_db_pools/lib/src/connection.rs
   |
@@ -43,7 +40,6 @@ error[E0277]: the trait bound `Vec<i32>: Poolable` is not satisfied
 9 | struct B(Vec<i32>);
   |          ^^^^^^^^ the trait `Poolable` is not implemented for `Vec<i32>`
   |
-  = help: the trait `Poolable` is implemented for `SqliteConnection`
 note: required by a bound in `ConnectionPool`
  --> $WORKSPACE/contrib/sync_db_pools/lib/src/connection.rs
   |

contrib/sync_db_pools/codegen/tests/ui-fail-stable/database-syntax.stderr

@@ -1,56 +1,56 @@
 error: unexpected end of input, expected string literal
- --> tests/ui-fail-stable/database-syntax.rs:6:1
+  --> tests/ui-fail-stable/database-syntax.rs:27:1
    |
-6 | #[database]
+27 | #[database]
    | ^^^^^^^^^^^
    |
    = note: this error originates in the attribute macro `database` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: expected string literal
- --> tests/ui-fail-stable/database-syntax.rs:9:12
+  --> tests/ui-fail-stable/database-syntax.rs:30:12
    |
-9 | #[database(1)]
+30 | #[database(1)]
    |            ^
 
 error: expected string literal
-  --> tests/ui-fail-stable/database-syntax.rs:12:12
+  --> tests/ui-fail-stable/database-syntax.rs:33:12
    |
-12 | #[database(123)]
+33 | #[database(123)]
    |            ^^^
 
 error: unexpected token
-  --> tests/ui-fail-stable/database-syntax.rs:15:20
+  --> tests/ui-fail-stable/database-syntax.rs:36:20
    |
-15 | #[database("hello" "hi")]
+36 | #[database("hello" "hi")]
    |                    ^^^^
 
 error: `database` attribute can only be used on structs
-  --> tests/ui-fail-stable/database-syntax.rs:19:1
+  --> tests/ui-fail-stable/database-syntax.rs:40:1
    |
-19 | enum Foo {  }
+40 | enum Foo {  }
    | ^^^^
 
 error: `database` attribute can only be applied to structs with exactly one unnamed field
          --- help: example: `struct MyDatabase(diesel::SqliteConnection);`
-  --> tests/ui-fail-stable/database-syntax.rs:22:11
+  --> tests/ui-fail-stable/database-syntax.rs:43:11
    |
-22 | struct Bar(diesel::SqliteConnection, diesel::SqliteConnection);
+43 | struct Bar(Connection, Connection);
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `database` attribute can only be used on structs
-  --> tests/ui-fail-stable/database-syntax.rs:25:1
+  --> tests/ui-fail-stable/database-syntax.rs:46:1
    |
-25 | union Baz {  }
+46 | union Baz {  }
    | ^^^^^
 
 error: `database` attribute cannot be applied to structs with generics
-  --> tests/ui-fail-stable/database-syntax.rs:28:9
+  --> tests/ui-fail-stable/database-syntax.rs:49:9
    |
-28 | struct E<'r>(&'r str);
+49 | struct E<'r>(&'r str);
    |         ^
 
 error: `database` attribute cannot be applied to structs with generics
-  --> tests/ui-fail-stable/database-syntax.rs:31:9
+  --> tests/ui-fail-stable/database-syntax.rs:52:9
    |
-31 | struct F<T>(T);
+52 | struct F<T>(T);
    |         ^

contrib/sync_db_pools/codegen/tests/ui-fail-stable/database-types.stderr

@@ -4,7 +4,6 @@ error[E0277]: the trait bound `Unknown: Poolable` is not satisfied
 6 | struct A(Unknown);
   |          ^^^^^^^ the trait `Poolable` is not implemented for `Unknown`
   |
-  = help: the trait `Poolable` is implemented for `SqliteConnection`
 note: required by a bound in `rocket_sync_db_pools::Connection`
  --> $WORKSPACE/contrib/sync_db_pools/lib/src/connection.rs
   |
@@ -17,7 +16,6 @@ error[E0277]: the trait bound `Vec<i32>: Poolable` is not satisfied
 9 | struct B(Vec<i32>);
   |          ^^^ the trait `Poolable` is not implemented for `Vec<i32>`
   |
-  = help: the trait `Poolable` is implemented for `SqliteConnection`
 note: required by a bound in `rocket_sync_db_pools::Connection`
  --> $WORKSPACE/contrib/sync_db_pools/lib/src/connection.rs
   |
@@ -30,7 +28,6 @@ error[E0277]: the trait bound `Unknown: Poolable` is not satisfied
 6 | struct A(Unknown);
   |          ^^^^^^^ the trait `Poolable` is not implemented for `Unknown`
   |
-  = help: the trait `Poolable` is implemented for `SqliteConnection`
 note: required by a bound in `ConnectionPool`
  --> $WORKSPACE/contrib/sync_db_pools/lib/src/connection.rs
   |
@@ -43,7 +40,6 @@ error[E0277]: the trait bound `Vec<i32>: Poolable` is not satisfied
 9 | struct B(Vec<i32>);
   |          ^^^ the trait `Poolable` is not implemented for `Vec<i32>`
   |
-  = help: the trait `Poolable` is implemented for `SqliteConnection`
 note: required by a bound in `ConnectionPool`
  --> $WORKSPACE/contrib/sync_db_pools/lib/src/connection.rs
   |

contrib/sync_db_pools/codegen/tests/ui-fail/database-syntax.rs

@@ -1,25 +1,46 @@
 use rocket_sync_db_pools::database;
 
-#[allow(unused_imports)]
+struct Connection;
-use rocket_sync_db_pools::diesel;
+struct Manager;
+
+use rocket::{Rocket, Build};
+use rocket_sync_db_pools::{r2d2, Poolable, PoolResult};
+
+impl r2d2::ManageConnection for Manager {
+    type Connection = Connection;
+    type Error = std::convert::Infallible;
+
+    fn connect(&self) -> Result<Self::Connection, Self::Error> { Ok(Connection) }
+    fn is_valid(&self, conn: &mut Self::Connection) -> Result<(), Self::Error> { Ok(()) }
+    fn has_broken(&self, conn: &mut Self::Connection) -> bool { true }
+}
+
+impl Poolable for Connection {
+    type Manager = Manager;
+    type Error = std::convert::Infallible;
+
+    fn pool(db_name: &str, rocket: &Rocket<Build>) -> PoolResult<Self> {
+        todo!()
+    }
+}
 
 #[database]
-struct A(diesel::SqliteConnection);
+struct A(Connection);
 
 #[database(1)]
-struct B(diesel::SqliteConnection);
+struct B(Connection);
 
 #[database(123)]
-struct C(diesel::SqliteConnection);
+struct C(Connection);
 
 #[database("hello" "hi")]
-struct D(diesel::SqliteConnection);
+struct D(Connection);
 
 #[database("test")]
 enum Foo {  }
 
 #[database("test")]
-struct Bar(diesel::SqliteConnection, diesel::SqliteConnection);
+struct Bar(Connection, Connection);
 
 #[database("test")]
 union Baz {  }

contrib/sync_db_pools/lib/src/poolable.rs

@@ -1,3 +1,4 @@
+#[allow(unused)]
 use std::time::Duration;
 
 use r2d2::ManageConnection;

core/codegen/tests/ui-fail-stable/async-entry.stderr

@@ -129,8 +129,9 @@ error[E0308]: mismatched types
   --> tests/ui-fail-stable/async-entry.rs:24:21
    |
 24 |       async fn main() {
-   |                       ^ expected `()` because of default return type
+   |                       ^
-   |  _____________________|
+   |                       |
+   |  _____________________expected `()` because of default return type
    | |
 25 | |         rocket::build()
 26 | |     }

examples/databases/Cargo.toml

@@ -7,8 +7,8 @@ publish = false
 
 [dependencies]
 rocket = { path = "../../core/lib", features = ["json"] }
-diesel = { version = "2.0.0", features = ["sqlite", "r2d2"] }
+diesel = "2"
-diesel_migrations = "2.0.0"
+diesel_migrations = "2"
 
 [dependencies.sqlx]
 version = "0.6.0"
@@ -17,7 +17,7 @@ features = ["macros", "offline", "migrate"]
 
 [dependencies.rocket_db_pools]
 path = "../../contrib/db_pools/lib/"
-features = ["sqlx_sqlite"]
+features = ["sqlx_sqlite", "diesel_mysql"]
 
 [dependencies.rocket_sync_db_pools]
 path = "../../contrib/sync_db_pools/lib/"

examples/databases/Rocket.toml

@@ -7,3 +7,6 @@ url = "db/sqlx/db.sqlite"
 [default.databases.diesel]
 url = "db/diesel/db.sqlite"
 timeout = 10
+
+[default.databases.diesel_mysql]
+url = "mysql://user:password@127.0.0.1/database"

examples/databases/db/diesel/mysql-migrations/20210329150332_create_posts_table/down.sql

@@ -0,0 +1 @@
+DROP TABLE posts;

examples/databases/db/diesel/mysql-migrations/20210329150332_create_posts_table/up.sql

@@ -0,0 +1,6 @@
+CREATE TABLE posts (
+    id INTEGER AUTO_INCREMENT PRIMARY KEY,
+    title VARCHAR(255) NOT NULL,
+    text TEXT NOT NULL,
+    published BOOLEAN NOT NULL DEFAULT FALSE
+);

examples/databases/src/diesel_mysql.rs

@@ -0,0 +1,97 @@
+use rocket::fairing::AdHoc;
+use rocket::response::{Debug, status::Created};
+use rocket::serde::{Serialize, Deserialize, json::Json};
+
+use rocket_db_pools::{Database, Connection};
+use rocket_db_pools::diesel::{MysqlPool, prelude::*};
+
+type Result<T, E = Debug<diesel::result::Error>> = std::result::Result<T, E>;
+
+#[derive(Database)]
+#[database("diesel_mysql")]
+struct Db(MysqlPool);
+
+#[derive(Debug, Clone, Deserialize, Serialize, Queryable, Insertable)]
+#[serde(crate = "rocket::serde")]
+#[diesel(table_name = posts)]
+struct Post {
+    #[serde(skip_deserializing)]
+    id: Option<i64>,
+    title: String,
+    text: String,
+    #[serde(skip_deserializing)]
+    published: bool,
+}
+
+diesel::table! {
+    posts (id) {
+        id -> Nullable<BigInt>,
+        title -> Text,
+        text -> Text,
+        published -> Bool,
+    }
+}
+
+#[post("/", data = "<post>")]
+async fn create(mut db: Connection<Db>, mut post: Json<Post>) -> Result<Created<Json<Post>>> {
+    diesel::sql_function!(fn last_insert_id() -> BigInt);
+
+    let post = db.transaction(|mut conn| Box::pin(async move {
+        diesel::insert_into(posts::table)
+            .values(&*post)
+            .execute(&mut conn)
+            .await?;
+
+        post.id = Some(posts::table
+            .select(last_insert_id())
+            .first(&mut conn)
+            .await?);
+
+        Ok::<_, diesel::result::Error>(post)
+    })).await?;
+
+    Ok(Created::new("/").body(post))
+}
+
+#[get("/")]
+async fn list(mut db: Connection<Db>) -> Result<Json<Vec<Option<i64>>>> {
+    let ids = posts::table
+        .select(posts::id)
+        .load(&mut db)
+        .await?;
+
+    Ok(Json(ids))
+}
+
+#[get("/<id>")]
+async fn read(mut db: Connection<Db>, id: i64) -> Option<Json<Post>> {
+    posts::table
+        .filter(posts::id.eq(id))
+        .first(&mut db)
+        .await
+        .map(Json)
+        .ok()
+}
+
+#[delete("/<id>")]
+async fn delete(mut db: Connection<Db>, id: i64) -> Result<Option<()>> {
+    let affected = diesel::delete(posts::table)
+        .filter(posts::id.eq(id))
+        .execute(&mut db)
+        .await?;
+
+    Ok((affected == 1).then(|| ()))
+}
+
+#[delete("/")]
+async fn destroy(mut db: Connection<Db>) -> Result<()> {
+    diesel::delete(posts::table).execute(&mut db).await?;
+    Ok(())
+}
+
+pub fn stage() -> AdHoc {
+    AdHoc::on_ignite("Diesel SQLite Stage", |rocket| async {
+        rocket.attach(Db::init())
+            .mount("/diesel-async/", routes![list, read, create, delete, destroy])
+    })
+}

examples/databases/src/diesel_sqlite.rs

@@ -3,9 +3,7 @@ use rocket::fairing::AdHoc;
 use rocket::response::{Debug, status::Created};
 use rocket::serde::{Serialize, Deserialize, json::Json};
 
-use rocket_sync_db_pools::diesel;
+use diesel::prelude::*;
-
-use self::diesel::prelude::*;
 
 #[database("diesel")]
 struct Db(diesel::SqliteConnection);

examples/databases/src/main.rs

@@ -5,12 +5,22 @@
 
 mod sqlx;
 mod diesel_sqlite;
+mod diesel_mysql;
 mod rusqlite;
 
+use rocket::response::Redirect;
+
+#[get("/")]
+fn index() -> Redirect {
+    Redirect::to(uri!("/sqlx", sqlx::list()))
+}
+
 #[launch]
 fn rocket() -> _ {
     rocket::build()
+        .mount("/", routes![index])
         .attach(sqlx::stage())
         .attach(rusqlite::stage())
         .attach(diesel_sqlite::stage())
+        .attach(diesel_mysql::stage())
 }

scripts/test.sh

@@ -82,6 +82,8 @@ function test_contrib() {
     sqlx_sqlite
     sqlx_mssql
     mongodb
+    diesel_mysql
+    diesel_postgres
   )
 
   SYNC_DB_POOLS_FEATURES=(