Merge #3067

3067: Fix task details serialization r=Kerollmops a=ManyTheFish

# Pull Request

- document addition task details always contain the field `indexedDocuments`
  - value is set to `null` when the task is enqueued or processing
  - value is set to `0` when the task is canceled or failed
- the field `deletedDocuments` of the document deletion task details is set to `0` when the task is canceled or failed
- the field `deletedDocuments` of the document clearAll task details is set to `0` when the task is canceled or failed
- the field `deletedTasks` of the task deletion task details is set to `0` when the task is canceled or failed
- the field `canceledTasks` of the task cancelation task details is set to `0` when the task is canceled or failed

## Related issue
Fixes #3057
Fixes #3058


Co-authored-by: ManyTheFish <many@meilisearch.com>

meilisearch-http/src/routes/tasks.rs

@@ -82,7 +82,7 @@ pub struct DetailsView {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub received_documents: Option<u64>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub indexed_documents: Option<u64>,
+    pub indexed_documents: Option<Option<u64>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub primary_key: Option<Option<String>>,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -112,7 +112,7 @@ impl From<Details> for DetailsView {
             Details::DocumentAdditionOrUpdate { received_documents, indexed_documents } => {
                 DetailsView {
                     received_documents: Some(received_documents),
-                    indexed_documents,
+                    indexed_documents: Some(indexed_documents),
                     ..DetailsView::default()
                 }
             }

meilisearch-http/tests/tasks/mod.rs

@@ -412,7 +412,7 @@ async fn test_summarized_delete_batch() {
       "canceledBy": null,
       "details": {
         "matchedDocuments": 3,
-        "deletedDocuments": null
+        "deletedDocuments": 0
       },
       "error": {
         "message": "Index `test` not found.",
@@ -471,7 +471,7 @@ async fn test_summarized_delete_document() {
       "canceledBy": null,
       "details": {
         "matchedDocuments": 1,
-        "deletedDocuments": null
+        "deletedDocuments": 0
       },
       "error": {
         "message": "Index `test` not found.",