fix(mongodb): guard aggregate execution paths

crates/dbx-core/src/db/mongo_driver.rs

@@ -83,6 +83,7 @@ pub async fn aggregate_documents(
     database: &str,
     collection: &str,
     pipeline_json: &str,
+    max_rows: Option<usize>,
 ) -> Result<MongoDocumentResult, String> {
     let json: serde_json::Value =
         serde_json::from_str(pipeline_json).map_err(|e| format!("Invalid pipeline JSON: {e}"))?;
@@ -93,12 +94,17 @@ pub async fn aggregate_documents(
         .collect::<Result<Vec<Document>, String>>()?;
     let col = client.database(database).collection::<Document>(collection);
     let mut cursor = col.aggregate(pipeline).await.map_err(|e| e.to_string())?;
+    let max_rows = max_rows.unwrap_or(100);
+    let fetch_limit = max_rows.saturating_add(1);
     let mut documents = Vec::new();
-    while cursor.advance().await.map_err(|e| e.to_string())? {
+    while documents.len() < fetch_limit && cursor.advance().await.map_err(|e| e.to_string())? {
         let doc = cursor.deserialize_current().map_err(|e| e.to_string())?;
         documents.push(bson_to_json(&Bson::Document(doc)));
     }
     let total = documents.len() as u64;
+    if documents.len() > max_rows {
+        documents.truncate(max_rows);
+    }
     Ok(MongoDocumentResult { documents, total })
 }
 

crates/dbx-core/src/mongo_ops.rs

@@ -77,11 +77,12 @@ pub async fn mongo_aggregate_documents_core(
     database: &str,
     collection: &str,
     pipeline_json: &str,
+    max_rows: Option<usize>,
 ) -> Result<MongoDocumentResult, String> {
     let connections = state.connections.read().await;
     match connections.get(connection_id).ok_or("Not found")? {
         PoolKind::MongoDb(client) => {
-            mongo_driver::aggregate_documents(client, database, collection, pipeline_json).await
+            mongo_driver::aggregate_documents(client, database, collection, pipeline_json, max_rows).await
         }
         PoolKind::Agent(_) => Err("MongoDB legacy agent does not support aggregate".to_string()),
         _ => Err("Not a MongoDB connection".to_string()),

crates/dbx-core/src/schema.rs

@@ -399,14 +399,7 @@ pub async fn list_tables_core(
 }
 
 fn collection_names_to_tables(names: Vec<String>, table_type: &str) -> Vec<db::TableInfo> {
-    names
-        .into_iter()
-        .map(|name| db::TableInfo {
-            name,
-            table_type: table_type.to_string(),
-            comment: None,
-        })
-        .collect()
+    names.into_iter().map(|name| db::TableInfo { name, table_type: table_type.to_string(), comment: None }).collect()
 }
 
 fn filter_table_infos(tables: Vec<db::TableInfo>, filter: Option<&str>, limit: Option<usize>) -> Vec<db::TableInfo> {