[Search] Log and return instead of swallow errors in Playground (#190796

)

## Summary

This stops the Kibana server from swallowing all playground errors,
instead logging them and then returning a meaningful error to the
frontend.

---------

Co-authored-by: kibanamachine <[email protected]>

x-pack/plugins/search_playground/server/routes.ts

@@ -57,7 +57,7 @@ export function defineRoutes({
         }),
       },
     },
-    errorHandler(async (context, request, response) => {
+    errorHandler(logger)(async (context, request, response) => {
       const { client } = (await context.core).elasticsearch;
 
       const { indices } = request.body;
@@ -89,14 +89,14 @@ export function defineRoutes({
         }),
       },
     },
-    errorHandler(async (context, request, response) => {
+    errorHandler(logger)(async (context, request, response) => {
       const [{ analytics }, { actions, cloud }] = await getStartServices();
 
       const { client } = (await context.core).elasticsearch;
       const aiClient = Assist({
         es_client: client.asCurrentUser,
       } as AssistClientOptionsWithClient);
-      const { messages, data } = await request.body;
+      const { messages, data } = request.body;
       const { chatModel, chatPrompt, questionRewritePrompt, connector } = await getChatParams(
         {
           connectorId: data.connector_id,
@@ -184,7 +184,7 @@ export function defineRoutes({
         }),
       },
     },
-    errorHandler(async (context, request, response) => {
+    errorHandler(logger)(async (context, request, response) => {
       const { name, expiresInDays, indices } = request.body;
       const { client } = (await context.core).elasticsearch;
 
@@ -223,7 +223,7 @@ export function defineRoutes({
         }),
       },
     },
-    errorHandler(async (context, request, response) => {
+    errorHandler(logger)(async (context, request, response) => {
       const { search_query: searchQuery, size } = request.query;
       const {
         client: { asCurrentUser },

x-pack/plugins/search_playground/server/utils/error_handler.ts

@@ -6,12 +6,22 @@
  */
 
 import { RequestHandlerWrapper } from '@kbn/core-http-server';
+import { KibanaServerError } from '@kbn/kibana-utils-plugin/common';
+import type { Logger } from '@kbn/logging';
 
-export const errorHandler: RequestHandlerWrapper = (handler) => {
+function isKibanaServerError(error: any): error is KibanaServerError {
+  return error.statusCode && error.message;
+}
+
+export const errorHandler: (logger: Logger) => RequestHandlerWrapper = (logger) => (handler) => {
   return async (context, request, response) => {
     try {
       return await handler(context, request, response);
     } catch (e) {
+      logger.error(e);
+      if (isKibanaServerError(e)) {
+        return response.customError({ statusCode: e.statusCode, body: e.message });
+      }
       throw e;
     }
   };

x-pack/plugins/search_playground/tsconfig.json

@@ -39,7 +39,8 @@
     "@kbn/analytics",
     "@kbn/usage-collection-plugin",
     "@kbn/console-plugin",
-    "@kbn/utility-types"
+    "@kbn/utility-types",
+    "@kbn/kibana-utils-plugin"
   ],
   "exclude": [
     "target/**/*",