RelationDef & RelationBuilder are Send & Sync (#898)

* `RelationDef` & `RelationBuilder` are `Send` & `Sync`

* [issues] add tests

Co-authored-by: Chris Tsang <chris.2y3@outlook.com>

issues/892/Cargo.toml

@@ -0,0 +1,17 @@
+[workspace]
+# A separate workspace
+
+[package]
+name = "sea-orm-issues-892"
+version = "0.1.0"
+authors = []
+edition = "2021"
+publish = false
+
+[dependencies]
+tokio = { version = "1.20.0", features = ["rt-multi-thread", "macros"] }
+
+[dependencies.sea-orm]
+path = "../../" # remove this line in your own project
+features = ["runtime-tokio-rustls", "sqlx-sqlite", "macros"]
+default-features = false

issues/892/src/main.rs

@@ -0,0 +1,19 @@
+use sea_orm::tests_cfg::{cake, cake_filling};
+use sea_orm::{Database, DbErr, EntityTrait, JoinType, QuerySelect, RelationTrait};
+
+#[tokio::main]
+async fn main() -> Result<(), DbErr> {
+    let db = Database::connect("sqlite::memory:").await?;
+
+    tokio::spawn(async move {
+        let _cakes = cake::Entity::find()
+            .join_rev(JoinType::InnerJoin, cake_filling::Relation::Cake.def())
+            .all(&db)
+            .await
+            .unwrap();
+    })
+    .await
+    .unwrap();
+
+    Ok(())
+}

src/entity/relation.rs

@@ -62,7 +62,7 @@ pub struct RelationDef {
     /// `UPDATE` Operation is performed
     pub on_update: Option<ForeignKeyAction>,
     /// Custom join ON condition
-    pub on_condition: Option<Box<dyn Fn(DynIden, DynIden) -> Condition>>,
+    pub on_condition: Option<Box<dyn Fn(DynIden, DynIden) -> Condition + Send + Sync>>,
     /// The name of foreign key constraint
     pub fk_name: Option<String>,
 }
@@ -85,7 +85,7 @@ impl std::fmt::Debug for RelationDef {
 
 fn debug_on_condition(
     d: &mut core::fmt::DebugStruct<'_, '_>,
-    on_condition: &Option<Box<dyn Fn(DynIden, DynIden) -> Condition>>,
+    on_condition: &Option<Box<dyn Fn(DynIden, DynIden) -> Condition + Send + Sync>>,
 ) {
     match on_condition {
         Some(func) => {
@@ -118,7 +118,7 @@ where
     is_owner: bool,
     on_delete: Option<ForeignKeyAction>,
     on_update: Option<ForeignKeyAction>,
-    on_condition: Option<Box<dyn Fn(DynIden, DynIden) -> Condition>>,
+    on_condition: Option<Box<dyn Fn(DynIden, DynIden) -> Condition + Send + Sync>>,
     fk_name: Option<String>,
 }
 
@@ -190,7 +190,7 @@ impl RelationDef {
     /// );
     pub fn on_condition<F>(mut self, f: F) -> Self
     where
-        F: Fn(DynIden, DynIden) -> Condition + 'static,
+        F: Fn(DynIden, DynIden) -> Condition + 'static + Send + Sync,
     {
         self.on_condition = Some(Box::new(f));
         self
@@ -270,7 +270,7 @@ where
     /// denoting the left-hand side and right-hand side table in the join expression.
     pub fn on_condition<F>(mut self, f: F) -> Self
     where
-        F: Fn(DynIden, DynIden) -> Condition + 'static,
+        F: Fn(DynIden, DynIden) -> Condition + 'static + Send + Sync,
     {
         self.on_condition = Some(Box::new(f));
         self
@@ -303,3 +303,19 @@ where
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::{
+        tests_cfg::{cake, fruit},
+        RelationBuilder, RelationDef,
+    };
+
+    #[test]
+    fn assert_relation_traits() {
+        fn assert_send_sync<T: Send + Sync>() {}
+
+        assert_send_sync::<RelationDef>();
+        assert_send_sync::<RelationBuilder<cake::Entity, fruit::Entity>>();
+    }
+}