fix(meilisearch): show per-index size in the index sidebar

crates/dbx-drivers/src/db/meilisearch_driver.rs

@@ -1093,10 +1093,39 @@ pub struct MeilisearchIndexOverview {
     pub updated_at: Option<String>,
     pub number_of_documents: u64,
     pub is_indexing: bool,
+    /// Raw document store size of *this* index in bytes (`rawDocumentDbSize`,
+    /// Meilisearch >= 1.14). `None` on servers that do not report per-index sizes.
+    pub document_size: Option<u64>,
+    /// Average size of one document in this index in bytes (`avgDocumentSize`,
+    /// Meilisearch >= 1.14). `None` on older servers.
+    pub avg_document_size: Option<u64>,
     /// Instance-wide database size in bytes; `None` when the API key cannot read instance stats.
+    /// It counts every index of the instance, so the UI only uses it as a fallback.
     pub database_size: Option<u64>,
 }
 
+/// Builds the index overview from the three responses the tab needs. Kept pure
+/// so the per-index size fields (Meilisearch >= 1.14) and the older-server
+/// fallback can be covered without a live server.
+fn parse_index_overview(
+    index: &str,
+    info: &Value,
+    stats: &Value,
+    instance_stats: Option<&Value>,
+) -> MeilisearchIndexOverview {
+    MeilisearchIndexOverview {
+        uid: info.get("uid").and_then(Value::as_str).unwrap_or(index).to_string(),
+        primary_key: info.get("primaryKey").and_then(Value::as_str).map(str::to_string),
+        created_at: info.get("createdAt").and_then(Value::as_str).map(str::to_string),
+        updated_at: info.get("updatedAt").and_then(Value::as_str).map(str::to_string),
+        number_of_documents: stats.get("numberOfDocuments").and_then(Value::as_u64).unwrap_or(0),
+        is_indexing: stats.get("isIndexing").and_then(Value::as_bool).unwrap_or(false),
+        document_size: stats.get("rawDocumentDbSize").and_then(Value::as_u64),
+        avg_document_size: stats.get("avgDocumentSize").and_then(Value::as_u64),
+        database_size: instance_stats.and_then(|value| value.get("databaseSize")).and_then(Value::as_u64),
+    }
+}
+
 pub async fn get_index_overview(client: &MeilisearchClient, index: &str) -> Result<MeilisearchIndexOverview, String> {
     let info = response_json(
         client
@@ -1109,22 +1138,11 @@ pub async fn get_index_overview(client: &MeilisearchClient, index: &str) -> Resu
     .await?;
     let stats = get_index_stats(client, index).await?;
     // Instance stats require broader key permissions, so keep them best-effort.
-    let database_size = match client.get("/stats").send().await {
-        Ok(response) => response_json(response, "instance stats lookup")
-            .await
-            .ok()
-            .and_then(|value| value.get("databaseSize").and_then(Value::as_u64)),
+    let instance_stats = match client.get("/stats").send().await {
+        Ok(response) => response_json(response, "instance stats lookup").await.ok(),
         Err(_) => None,
     };
-    Ok(MeilisearchIndexOverview {
-        uid: info.get("uid").and_then(Value::as_str).unwrap_or(index).to_string(),
-        primary_key: info.get("primaryKey").and_then(Value::as_str).map(str::to_string),
-        created_at: info.get("createdAt").and_then(Value::as_str).map(str::to_string),
-        updated_at: info.get("updatedAt").and_then(Value::as_str).map(str::to_string),
-        number_of_documents: stats.get("numberOfDocuments").and_then(Value::as_u64).unwrap_or(0),
-        is_indexing: stats.get("isIndexing").and_then(Value::as_bool).unwrap_or(false),
-        database_size,
-    })
+    Ok(parse_index_overview(index, &info, &stats, instance_stats.as_ref()))
 }
 
 pub async fn delete_index(client: &MeilisearchClient, index: &str) -> Result<(), String> {
@@ -1904,8 +1922,9 @@ mod tests {
     use super::{
         decode_bounded_rest_body, decoded_identity, ensure_task_index, filter_expression, identity_path,
         meilisearch_base_url, meilisearch_filter_from_request, meilisearch_search_body, meilisearch_sort_from_request,
-        parse_key, parse_meilisearch_search_response, parse_rest_request_line, parse_system_stats, task_selector_query,
-        MeilisearchClient, MeilisearchOverviewSection, MeilisearchTask, MeilisearchTaskSelector,
+        parse_index_overview, parse_key, parse_meilisearch_search_response, parse_rest_request_line,
+        parse_system_stats, task_selector_query, MeilisearchClient, MeilisearchOverviewSection, MeilisearchTask,
+        MeilisearchTaskSelector,
     };
     use reqwest::Method;
     use serde_json::{json, Value};
@@ -2037,6 +2056,57 @@ mod tests {
         assert!(indexless.contains("not associated with an index"));
     }
 
+    #[test]
+    fn index_overview_prefers_the_per_index_size_when_the_server_reports_one() {
+        // Meilisearch >= 1.14: /indexes/{uid}/stats carries the index's own sizes.
+        let overview = parse_index_overview(
+            "movies",
+            &json!({ "uid": "movies", "primaryKey": "id", "createdAt": "2026-08-01T00:00:00Z" }),
+            &json!({
+                "numberOfDocuments": 256,
+                "indexSize": 90_000_000,
+                "rawDocumentDbSize": 26_935_296,
+                "avgDocumentSize": 105_216,
+                "isIndexing": false
+            }),
+            Some(&json!({ "databaseSize": 999_999_999 })),
+        );
+
+        assert_eq!(overview.document_size, Some(26_935_296));
+        assert_eq!(overview.avg_document_size, Some(105_216));
+        // The instance-wide number stays available, but the UI must not present it as this index's size.
+        assert_eq!(overview.database_size, Some(999_999_999));
+        assert_eq!(overview.number_of_documents, 256);
+    }
+
+    #[test]
+    fn index_overview_leaves_per_index_sizes_unset_on_older_servers() {
+        // Meilisearch <= 1.13 answers index stats without rawDocumentDbSize / avgDocumentSize.
+        let overview = parse_index_overview(
+            "movies",
+            &json!({ "uid": "movies" }),
+            &json!({ "numberOfDocuments": 12, "isIndexing": true, "fieldDistribution": { "id": 12 } }),
+            Some(&json!({ "databaseSize": 4096 })),
+        );
+
+        assert_eq!(overview.document_size, None);
+        assert_eq!(overview.avg_document_size, None);
+        assert_eq!(overview.database_size, Some(4096));
+        assert_eq!(overview.number_of_documents, 12);
+        assert!(overview.is_indexing);
+    }
+
+    #[test]
+    fn index_overview_survives_a_forbidden_instance_stats_lookup() {
+        let overview = parse_index_overview("movies", &json!({}), &json!({ "numberOfDocuments": 1 }), None);
+
+        assert_eq!(overview.database_size, None);
+        assert_eq!(overview.document_size, None);
+        assert_eq!(overview.uid, "movies");
+        assert_eq!(overview.number_of_documents, 1);
+        assert!(!overview.is_indexing);
+    }
+
     #[test]
     fn system_stats_compute_totals_and_top_ten_deterministically() {
         let indexes = (0..12)