APM: Explicitly type Setup to prevent hitting TS limits

Author: dgieselaar

x-pack/legacy/plugins/apm/server/lib/helpers/setup_request.ts

@@ -7,10 +7,15 @@
 import { Legacy } from 'kibana';
 import { Server } from 'hapi';
 import moment from 'moment';
+import { KibanaConfig } from 'src/legacy/server/kbn_server';
 import { getESClient } from './es_client';
 import { getUiFiltersES } from './convert_ui_filters/get_ui_filters_es';
-import { PromiseReturnType } from '../../../typings/common';
-import { getApmIndices } from '../settings/apm_indices/get_apm_indices';
+import {
+  getApmIndices,
+  ApmIndicesConfig
+} from '../settings/apm_indices/get_apm_indices';
+import { ESFilter } from '../../../typings/elasticsearch';
+import { ESClient } from './es_client';
 
 function decodeUiFilters(server: Server, uiFiltersEncoded?: string) {
   if (!uiFiltersEncoded) {
@@ -26,9 +31,20 @@ export interface APMRequestQuery {
   end?: string;
   uiFilters?: string;
 }
+// Explicitly type Setup to prevent TS initialization errors
+// https://github.com/microsoft/TypeScript/issues/34933
 
-export type Setup = PromiseReturnType<typeof setupRequest>;
-export async function setupRequest(req: Legacy.Request) {
+export interface Setup {
+  start: number;
+  end: number;
+  uiFiltersES: ESFilter[];
+  client: ESClient;
+  internalClient: ESClient;
+  config: KibanaConfig;
+  indices: ApmIndicesConfig;
+}
+
+export async function setupRequest(req: Legacy.Request): Promise<Setup> {
   const query = (req.query as unknown) as APMRequestQuery;
   const { server } = req;
   const savedObjectsClient = server.savedObjects.getScopedSavedObjectsClient(