fix the index deletion when the index doesn’t exists but would be created by one of the autobatched tasks

index-scheduler/src/batch.rs

@@ -74,6 +74,7 @@ pub(crate) enum Batch {
     IndexDeletion {
         index_uid: String,
         tasks: Vec<Task>,
+        index_has_been_created: bool,
     },
     IndexSwap {
         task: Task,
@@ -444,6 +445,7 @@ impl IndexScheduler {
             }
             BatchKind::IndexDeletion { ids } => Ok(Some(Batch::IndexDeletion {
                 index_uid,
+                index_has_been_created: must_create_index,
                 tasks: self.get_existing_tasks(rtxn, ids)?,
             })),
             BatchKind::IndexSwap { id } => {
@@ -796,18 +798,25 @@ impl IndexScheduler {
             }
             Batch::IndexDeletion {
                 index_uid,
+                index_has_been_created,
                 mut tasks,
             } => {
                 let wtxn = self.env.write_txn()?;
 
-                let number_of_documents = {
+                // it's possible that the index doesn't exist
+                let number_of_documents = || -> Result<u64> {
                     let index = self.index_mapper.index(&wtxn, &index_uid)?;
                     let index_rtxn = index.read_txn()?;
-                    index.number_of_documents(&index_rtxn)?
-                };
+                    Ok(index.number_of_documents(&index_rtxn)?)
+                }()
+                .unwrap_or_default();
 
                 // The write transaction is directly owned and commited inside.
-                self.index_mapper.delete_index(wtxn, &index_uid)?;
+                match self.index_mapper.delete_index(wtxn, &index_uid) {
+                    Ok(()) => (),
+                    Err(Error::IndexNotFound(_)) if index_has_been_created => (),
+                    Err(e) => return Err(e),
+                }
 
                 // We set all the tasks details to the default value.
                 for task in &mut tasks {

index-scheduler/src/lib.rs

@@ -1327,6 +1327,45 @@ mod tests {
         snapshot!(snapshot_index_scheduler(&index_scheduler), name: "second_swap_processed");
     }
 
+    #[test]
+    fn document_addition_and_index_deletion_on_unexisting_index() {
+        let (index_scheduler, handle) = IndexScheduler::test(true);
+
+        let content = r#"
+        {
+            "id": 1,
+            "doggo": "bob"
+        }"#;
+
+        let (uuid, mut file) = index_scheduler.create_update_file_with_uuid(0).unwrap();
+        let documents_count =
+            meilisearch_types::document_formats::read_json(content.as_bytes(), file.as_file_mut())
+                .unwrap() as u64;
+        file.persist().unwrap();
+        index_scheduler
+            .register(KindWithContent::DocumentImport {
+                index_uid: S("doggos"),
+                primary_key: Some(S("id")),
+                method: ReplaceDocuments,
+                content_file: uuid,
+                documents_count,
+                allow_index_creation: true,
+            })
+            .unwrap();
+        index_scheduler
+            .register(KindWithContent::IndexDeletion {
+                index_uid: S("doggos"),
+            })
+            .unwrap();
+
+        snapshot!(snapshot_index_scheduler(&index_scheduler));
+
+        handle.wait_till(Breakpoint::Start); // before anything happens.
+        handle.wait_till(Breakpoint::Start); // after the execution of the two tasks in a single batch.
+
+        snapshot!(snapshot_index_scheduler(&index_scheduler));
+    }
+
     #[macro_export]
     macro_rules! debug_snapshot {
         ($value:expr, @$snapshot:literal) => {{