editoast: add Deadlocks comment

Author: hamz2a

editoast/editoast_models/src/db_connection_pool.rs

@@ -134,6 +134,14 @@ impl DbConnectionPoolV2 {
     /// # }
     /// ```
     ///
+    /// ### Deadlocks
+    ///
+    /// We encountered a deadlock error in our tests,
+    /// especially those using `empty_infra` and `small_infra`.
+    /// Adding `#[serial_test::serial]` solved the issue.
+    /// We tried increasing the deadlock timeout, but that didn't work.
+    /// Using random `infra_id` with rand didn't help either.
+    ///
     /// ## Guidelines
     ///
     /// To prevent these issues, prefer the following patterns:

editoast/src/modelsv2/infra.rs

@@ -350,6 +350,7 @@ pub mod tests {
     }
 
     #[rstest]
+    // PostgreSQL deadlock can happen in this test, see section `Deadlock` of [DbConnectionPoolV2::get] for more information
     #[serial_test::serial]
     async fn persists_railjson_ko_version() {
         let db_pool = DbConnectionPoolV2::for_tests();

editoast/src/views/infra/mod.rs

@@ -658,6 +658,7 @@ pub mod tests {
     }
 
     #[rstest]
+    // PostgreSQL deadlock can happen in this test, see section `Deadlock` of [DbConnectionPoolV2::get] for more information
     #[serial_test::serial]
     async fn infra_clone_empty() {
         let app = TestAppBuilder::default_app();
@@ -682,7 +683,9 @@ pub mod tests {
         nb: i64,
     }
 
-    #[rstest] // Slow test
+    #[rstest]
+    // Slow test
+    // PostgreSQL deadlock can happen in this test, see section `Deadlock` of [DbConnectionPoolV2::get] for more information
     #[serial_test::serial]
     async fn infra_clone() {
         let app = TestAppBuilder::default_app();

editoast/src/views/infra/railjson.rs

@@ -196,6 +196,7 @@ mod tests {
     use editoast_schemas::infra::SwitchType;
 
     #[rstest]
+    // PostgreSQL deadlock can happen in this test, see section `Deadlock` of [DbConnectionPoolV2::get] for more information
     #[serial_test::serial]
     async fn test_get_railjson() {
         let app = TestAppBuilder::default_app();
@@ -221,6 +222,7 @@ mod tests {
     }
 
     #[rstest]
+    // PostgreSQL deadlock can happen in this test, see section `Deadlock` of [DbConnectionPoolV2::get] for more information
     #[serial_test::serial]
     async fn test_post_railjson() {
         let app = TestAppBuilder::default_app();