Add force_synthethic_source parameter (#2472)

(cherry picked from commit bda8a6d)

Author: pquentin

output/schema/schema.json

@@ -41,6 +41,13 @@ export interface Request extends RequestBase {
     index: IndexName
   }
   query_parameters: {
+    /**
+     * Should this request force synthetic _source?
+     * Use this to test if the mapping supports synthetic _source and to get a sense of the worst case performance.
+     * Fetches with this enabled will be slower the enabling synthetic source natively in the index.
+     * @availability stack since=8.4.0 visibility=feature_flag feature_flag=es.index_mode_feature_flag_registered
+     */
+    force_synthetic_source?: boolean
     /**
      * Specifies the node or shard the operation should be performed on. Random by default.
      */

output/schema/validation-errors.json

@@ -36,6 +36,13 @@ export interface Request extends RequestBase {
     index?: IndexName
   }
   query_parameters: {
+    /**
+     * Should this request force synthetic _source?
+     * Use this to test if the mapping supports synthetic _source and to get a sense of the worst case performance.
+     * Fetches with this enabled will be slower the enabling synthetic source natively in the index.
+     * @availability stack since=8.4.0 visibility=feature_flag feature_flag=es.index_mode_feature_flag_registered
+     */
+    force_synthetic_source?: boolean
     /**
      * Specifies the node or shard the operation should be performed on. Random by default.
      */

output/typescript/types.ts

@@ -324,6 +324,13 @@ export interface Request extends RequestBase {
      * @doc_id sort-search-results
      */
     sort?: string | string[]
+    /**
+     * Should this request force synthetic _source?
+     * Use this to test if the mapping supports synthetic _source and to get a sense of the worst case performance.
+     * Fetches with this enabled will be slower the enabling synthetic source natively in the index.
+     * @availability stack since=8.4.0 visibility=feature_flag feature_flag=es.index_mode_feature_flag_registered
+     */
+    force_synthetic_source?: boolean
   }
   // We should keep this in sync with the multi search request body.
   body: {