Add plugin start contract to getStartServices return value (#61216)

* add plugin own contract as third element of getStartServices result

* adapt plugins code

* update tests

* revert unknown to use void again

* update generated doc

* fix UT

* update mock to allow non-object `pluginStartContract`

* add @typeParam documentation

docs/development/core/public/kibana-plugin-core-public.coresetup.getstartservices.md

@@ -9,5 +9,5 @@
 <b>Signature:</b>
 
 ```typescript
-getStartServices: StartServicesAccessor<TPluginsStart>;
+getStartServices: StartServicesAccessor<TPluginsStart, TStart>;
 ```

docs/development/core/public/kibana-plugin-core-public.coresetup.md

@@ -9,7 +9,7 @@ Core services exposed to the `Plugin` setup lifecycle
 <b>Signature:</b>
 
 ```typescript
-export interface CoreSetup<TPluginsStart extends object = object> 
+export interface CoreSetup<TPluginsStart extends object = object, TStart = unknown> 
 ```
 
 ## Properties
@@ -19,7 +19,7 @@ export interface CoreSetup<TPluginsStart extends object = object>
 |  [application](./kibana-plugin-core-public.coresetup.application.md) | <code>ApplicationSetup</code> | [ApplicationSetup](./kibana-plugin-core-public.applicationsetup.md) |
 |  [context](./kibana-plugin-core-public.coresetup.context.md) | <code>ContextSetup</code> | [ContextSetup](./kibana-plugin-core-public.contextsetup.md) |
 |  [fatalErrors](./kibana-plugin-core-public.coresetup.fatalerrors.md) | <code>FatalErrorsSetup</code> | [FatalErrorsSetup](./kibana-plugin-core-public.fatalerrorssetup.md) |
-|  [getStartServices](./kibana-plugin-core-public.coresetup.getstartservices.md) | <code>StartServicesAccessor&lt;TPluginsStart&gt;</code> | [StartServicesAccessor](./kibana-plugin-core-public.startservicesaccessor.md) |
+|  [getStartServices](./kibana-plugin-core-public.coresetup.getstartservices.md) | <code>StartServicesAccessor&lt;TPluginsStart, TStart&gt;</code> | [StartServicesAccessor](./kibana-plugin-core-public.startservicesaccessor.md) |
 |  [http](./kibana-plugin-core-public.coresetup.http.md) | <code>HttpSetup</code> | [HttpSetup](./kibana-plugin-core-public.httpsetup.md) |
 |  [injectedMetadata](./kibana-plugin-core-public.coresetup.injectedmetadata.md) | <code>{</code><br/><code>        getInjectedVar: (name: string, defaultValue?: any) =&gt; unknown;</code><br/><code>    }</code> | exposed temporarily until https://github.com/elastic/kibana/issues/41990 done use \*only\* to retrieve config values. There is no way to set injected values in the new platform. Use the legacy platform API instead. |
 |  [notifications](./kibana-plugin-core-public.coresetup.notifications.md) | <code>NotificationsSetup</code> | [NotificationsSetup](./kibana-plugin-core-public.notificationssetup.md) |

docs/development/core/public/kibana-plugin-core-public.legacycoresetup.md

@@ -13,7 +13,7 @@ Setup interface exposed to the legacy platform via the `ui/new_platform` module.
 <b>Signature:</b>
 
 ```typescript
-export interface LegacyCoreSetup extends CoreSetup<any> 
+export interface LegacyCoreSetup extends CoreSetup<any, any> 
 ```
 
 ## Remarks

docs/development/core/public/kibana-plugin-core-public.plugin.setup.md

@@ -7,14 +7,14 @@
 <b>Signature:</b>
 
 ```typescript
-setup(core: CoreSetup<TPluginsStart>, plugins: TPluginsSetup): TSetup | Promise<TSetup>;
+setup(core: CoreSetup<TPluginsStart, TStart>, plugins: TPluginsSetup): TSetup | Promise<TSetup>;
 ```
 
 ## Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  core | <code>CoreSetup&lt;TPluginsStart&gt;</code> |  |
+|  core | <code>CoreSetup&lt;TPluginsStart, TStart&gt;</code> |  |
 |  plugins | <code>TPluginsSetup</code> |  |
 
 <b>Returns:</b>

docs/development/core/public/kibana-plugin-core-public.startservicesaccessor.md

@@ -9,5 +9,5 @@ Allows plugins to get access to APIs available in start inside async handlers, s
 <b>Signature:</b>
 
 ```typescript
-export declare type StartServicesAccessor<TPluginsStart extends object = object> = () => Promise<[CoreStart, TPluginsStart]>;
+export declare type StartServicesAccessor<TPluginsStart extends object = object, TStart = unknown> = () => Promise<[CoreStart, TPluginsStart, TStart]>;
 ```

docs/development/core/server/kibana-plugin-core-server.coresetup.getstartservices.md

@@ -9,5 +9,5 @@
 <b>Signature:</b>
 
 ```typescript
-getStartServices: StartServicesAccessor<TPluginsStart>;
+getStartServices: StartServicesAccessor<TPluginsStart, TStart>;
 ```

docs/development/core/server/kibana-plugin-core-server.coresetup.md

@@ -9,7 +9,7 @@ Context passed to the plugins `setup` method.
 <b>Signature:</b>
 
 ```typescript
-export interface CoreSetup<TPluginsStart extends object = object> 
+export interface CoreSetup<TPluginsStart extends object = object, TStart = unknown> 
 ```
 
 ## Properties
@@ -19,7 +19,7 @@ export interface CoreSetup<TPluginsStart extends object = object>
 |  [capabilities](./kibana-plugin-core-server.coresetup.capabilities.md) | <code>CapabilitiesSetup</code> | [CapabilitiesSetup](./kibana-plugin-core-server.capabilitiessetup.md) |
 |  [context](./kibana-plugin-core-server.coresetup.context.md) | <code>ContextSetup</code> | [ContextSetup](./kibana-plugin-core-server.contextsetup.md) |
 |  [elasticsearch](./kibana-plugin-core-server.coresetup.elasticsearch.md) | <code>ElasticsearchServiceSetup</code> | [ElasticsearchServiceSetup](./kibana-plugin-core-server.elasticsearchservicesetup.md) |
-|  [getStartServices](./kibana-plugin-core-server.coresetup.getstartservices.md) | <code>StartServicesAccessor&lt;TPluginsStart&gt;</code> | [StartServicesAccessor](./kibana-plugin-core-server.startservicesaccessor.md) |
+|  [getStartServices](./kibana-plugin-core-server.coresetup.getstartservices.md) | <code>StartServicesAccessor&lt;TPluginsStart, TStart&gt;</code> | [StartServicesAccessor](./kibana-plugin-core-server.startservicesaccessor.md) |
 |  [http](./kibana-plugin-core-server.coresetup.http.md) | <code>HttpServiceSetup</code> | [HttpServiceSetup](./kibana-plugin-core-server.httpservicesetup.md) |
 |  [metrics](./kibana-plugin-core-server.coresetup.metrics.md) | <code>MetricsServiceSetup</code> | [MetricsServiceSetup](./kibana-plugin-core-server.metricsservicesetup.md) |
 |  [savedObjects](./kibana-plugin-core-server.coresetup.savedobjects.md) | <code>SavedObjectsServiceSetup</code> | [SavedObjectsServiceSetup](./kibana-plugin-core-server.savedobjectsservicesetup.md) |

docs/development/core/server/kibana-plugin-core-server.startservicesaccessor.md

@@ -9,5 +9,5 @@ Allows plugins to get access to APIs available in start inside async handlers. P
 <b>Signature:</b>
 
 ```typescript
-export declare type StartServicesAccessor<TPluginsStart extends object = object> = () => Promise<[CoreStart, TPluginsStart]>;
+export declare type StartServicesAccessor<TPluginsStart extends object = object, TStart = unknown> = () => Promise<[CoreStart, TPluginsStart, TStart]>;
 ```

examples/alerting_example/public/plugin.tsx

@@ -17,7 +17,7 @@
  * under the License.
  */
 
-import { Plugin, CoreSetup, AppMountParameters, CoreStart } from 'kibana/public';
+import { Plugin, CoreSetup, AppMountParameters } from 'kibana/public';
 import { PluginSetupContract as AlertingSetup } from '../../../x-pack/plugins/alerting/public';
 import { ChartsPluginStart } from '../../../src/plugins/charts/public';
 import { TriggersAndActionsUIPublicPluginSetup } from '../../../x-pack/plugins/triggers_actions_ui/public';
@@ -43,17 +43,14 @@ export interface AlertingExamplePublicStartDeps {
 
 export class AlertingExamplePlugin implements Plugin<Setup, Start, AlertingExamplePublicSetupDeps> {
   public setup(
-    core: CoreSetup<AlertingExamplePublicStartDeps>,
+    core: CoreSetup<AlertingExamplePublicStartDeps, Start>,
     { alerting, triggers_actions_ui }: AlertingExamplePublicSetupDeps
   ) {
     core.application.register({
       id: 'AlertingExample',
       title: 'Alerting Example',
       async mount(params: AppMountParameters) {
-        const [coreStart, depsStart]: [
-          CoreStart,
-          AlertingExamplePublicStartDeps
-        ] = await core.getStartServices();
+        const [coreStart, depsStart] = await core.getStartServices();
         const { renderApp } = await import('./application');
         return renderApp(coreStart, depsStart, params);
       },

examples/bfetch_explorer/public/plugin.tsx

@@ -34,7 +34,10 @@ export interface BfetchExplorerStartPlugins {
 }
 
 export class BfetchExplorerPlugin implements Plugin {
-  public setup(core: CoreSetup<BfetchExplorerStartPlugins>, plugins: BfetchExplorerSetupPlugins) {
+  public setup(
+    core: CoreSetup<BfetchExplorerStartPlugins, void>,
+    plugins: BfetchExplorerSetupPlugins
+  ) {
     const double = plugins.bfetch.batchedFunction<{ num: number }, { num: number }>({
       url: '/bfetch_explorer/double',
     });

examples/embeddable_examples/public/index.ts

@@ -26,9 +26,18 @@ export {
 export { ListContainer, LIST_CONTAINER } from './list_container';
 export { TODO_EMBEDDABLE } from './todo';
 
-import { EmbeddableExamplesPlugin } from './plugin';
+import {
+  EmbeddableExamplesPlugin,
+  EmbeddableExamplesSetupDependencies,
+  EmbeddableExamplesStartDependencies,
+} from './plugin';
 
 export { SearchableListContainer, SEARCHABLE_LIST_CONTAINER } from './searchable_list_container';
 export { MULTI_TASK_TODO_EMBEDDABLE } from './multi_task_todo';
 
-export const plugin: PluginInitializer<void, void> = () => new EmbeddableExamplesPlugin();
+export const plugin: PluginInitializer<
+  void,
+  void,
+  EmbeddableExamplesSetupDependencies,
+  EmbeddableExamplesStartDependencies
+> = () => new EmbeddableExamplesPlugin();

examples/embeddable_examples/public/plugin.ts

@@ -28,11 +28,11 @@ import {
 } from './searchable_list_container';
 import { LIST_CONTAINER, ListContainerFactory } from './list_container';
 
-interface EmbeddableExamplesSetupDependencies {
+export interface EmbeddableExamplesSetupDependencies {
   embeddable: EmbeddableSetup;
 }
 
-interface EmbeddableExamplesStartDependencies {
+export interface EmbeddableExamplesStartDependencies {
   embeddable: EmbeddableStart;
 }
 

examples/search_explorer/public/plugin.tsx

@@ -21,7 +21,7 @@ import { Plugin, CoreSetup, AppMountParameters } from 'kibana/public';
 import { AppPluginStartDependencies } from './types';
 
 export class SearchExplorerPlugin implements Plugin {
-  public setup(core: CoreSetup<AppPluginStartDependencies>) {
+  public setup(core: CoreSetup<AppPluginStartDependencies, void>) {
     core.application.register({
       id: 'searchExplorer',
       title: 'Search Explorer',

src/core/public/index.ts

@@ -177,13 +177,18 @@ export { MountPoint, UnmountCallback, PublicUiSettingsParams } from './types';
 /**
  * Core services exposed to the `Plugin` setup lifecycle
  *
+ * @typeParam TPluginsStart - the type of the consuming plugin's start dependencies. Should be the same
+ *                            as the consuming {@link Plugin}'s `TPluginsStart` type. Used by `getStartServices`.
+ * @typeParam TStart - the type of the consuming plugin's start contract. Should be the same as the
+ *                     consuming {@link Plugin}'s `TStart` type. Used by `getStartServices`.
+ *
  * @public
  *
  * @internalRemarks We document the properties with \@link tags to improve
  * navigation in the generated docs until there's a fix for
  * https://github.com/Microsoft/web-build-tools/issues/1237
  */
-export interface CoreSetup<TPluginsStart extends object = object> {
+export interface CoreSetup<TPluginsStart extends object = object, TStart = unknown> {
   /** {@link ApplicationSetup} */
   application: ApplicationSetup;
   /**
@@ -209,7 +214,7 @@ export interface CoreSetup<TPluginsStart extends object = object> {
     getInjectedVar: (name: string, defaultValue?: any) => unknown;
   };
   /** {@link StartServicesAccessor} */
-  getStartServices: StartServicesAccessor<TPluginsStart>;
+  getStartServices: StartServicesAccessor<TPluginsStart, TStart>;
 }
 
 /**
@@ -219,9 +224,10 @@ export interface CoreSetup<TPluginsStart extends object = object> {
  *
  * @public
  */
-export type StartServicesAccessor<TPluginsStart extends object = object> = () => Promise<
-  [CoreStart, TPluginsStart]
->;
+export type StartServicesAccessor<
+  TPluginsStart extends object = object,
+  TStart = unknown
+> = () => Promise<[CoreStart, TPluginsStart, TStart]>;
 
 /**
  * Core services exposed to the `Plugin` start lifecycle
@@ -274,7 +280,7 @@ export interface CoreStart {
  * @public
  * @deprecated
  */
-export interface LegacyCoreSetup extends CoreSetup<any> {
+export interface LegacyCoreSetup extends CoreSetup<any, any> {
   /** @deprecated */
   injectedMetadata: InjectedMetadataSetup;
 }

src/core/public/legacy/legacy_service.ts

@@ -57,7 +57,7 @@ export class LegacyPlatformService {
   public readonly legacyId = Symbol();
   private bootstrapModule?: BootstrapModule;
   private targetDomElement?: HTMLElement;
-  private readonly startDependencies$ = new Subject<[LegacyCoreStart, object]>();
+  private readonly startDependencies$ = new Subject<[LegacyCoreStart, object, {}]>();
   private readonly startDependencies = this.startDependencies$.pipe(first()).toPromise();
 
   constructor(private readonly params: LegacyPlatformParams) {}
@@ -129,7 +129,7 @@ export class LegacyPlatformService {
       },
     };
 
-    this.startDependencies$.next([legacyCore, plugins]);
+    this.startDependencies$.next([legacyCore, plugins, {}]);
 
     // Inject parts of the new platform into parts of the legacy platform
     // so that legacy APIs/modules can mimic their new platform counterparts

src/core/public/mocks.ts

@@ -49,13 +49,22 @@ export { uiSettingsServiceMock } from './ui_settings/ui_settings_service.mock';
 export { savedObjectsServiceMock } from './saved_objects/saved_objects_service.mock';
 export { scopedHistoryMock } from './application/scoped_history.mock';
 
-function createCoreSetupMock({ basePath = '' } = {}) {
+function createCoreSetupMock({
+  basePath = '',
+  pluginStartDeps = {},
+  pluginStartContract,
+}: {
+  basePath?: string;
+  pluginStartDeps?: object;
+  pluginStartContract?: any;
+} = {}) {
   const mock = {
     application: applicationServiceMock.createSetupContract(),
     context: contextServiceMock.createSetupContract(),
     fatalErrors: fatalErrorsServiceMock.createSetupContract(),
-    getStartServices: jest.fn<Promise<[ReturnType<typeof createCoreStartMock>, object]>, []>(() =>
-      Promise.resolve([createCoreStartMock({ basePath }), {}])
+    getStartServices: jest.fn<Promise<[ReturnType<typeof createCoreStartMock>, object, any]>, []>(
+      () =>
+        Promise.resolve([createCoreStartMock({ basePath }), pluginStartDeps, pluginStartContract])
     ),
     http: httpServiceMock.createSetupContract({ basePath }),
     notifications: notificationServiceMock.createSetupContract(),

src/core/public/plugins/plugin.test.ts

@@ -109,6 +109,10 @@ describe('PluginWrapper', () => {
   test("`start` resolves `startDependencies` Promise after plugin's start", async () => {
     expect.assertions(2);
 
+    const pluginStartContract = {
+      someApi: () => 'foo',
+    };
+
     let startDependenciesResolved = false;
     mockPluginLoader.mockResolvedValueOnce(() => ({
       setup: jest.fn(),
@@ -116,6 +120,7 @@ describe('PluginWrapper', () => {
         // Add small delay to ensure startDependencies is not resolved until after the plugin instance's start resolves.
         await new Promise(resolve => setTimeout(resolve, 10));
         expect(startDependenciesResolved).toBe(false);
+        return pluginStartContract;
       },
     }));
     await plugin.load(addBasePath);
@@ -127,7 +132,7 @@ describe('PluginWrapper', () => {
     // called.
     const startDependenciesCheck = plugin.startDependencies.then(res => {
       startDependenciesResolved = true;
-      expect(res).toEqual([context, deps]);
+      expect(res).toEqual([context, deps, pluginStartContract]);
     });
     await plugin.start(context, deps);
     await startDependenciesCheck;

src/core/public/plugins/plugin.ts

@@ -35,7 +35,7 @@ export interface Plugin<
   TPluginsSetup extends object = object,
   TPluginsStart extends object = object
 > {
-  setup(core: CoreSetup<TPluginsStart>, plugins: TPluginsSetup): TSetup | Promise<TSetup>;
+  setup(core: CoreSetup<TPluginsStart, TStart>, plugins: TPluginsSetup): TSetup | Promise<TSetup>;
   start(core: CoreStart, plugins: TPluginsStart): TStart | Promise<TStart>;
   stop?(): void;
 }
@@ -72,7 +72,7 @@ export class PluginWrapper<
   private initializer?: PluginInitializer<TSetup, TStart, TPluginsSetup, TPluginsStart>;
   private instance?: Plugin<TSetup, TStart, TPluginsSetup, TPluginsStart>;
 
-  private readonly startDependencies$ = new Subject<[CoreStart, TPluginsStart]>();
+  private readonly startDependencies$ = new Subject<[CoreStart, TPluginsStart, TStart]>();
   public readonly startDependencies = this.startDependencies$.pipe(first()).toPromise();
 
   constructor(
@@ -105,7 +105,7 @@ export class PluginWrapper<
    * @param plugins The dictionary where the key is the dependency name and the value
    * is the contract returned by the dependency's `setup` function.
    */
-  public async setup(setupContext: CoreSetup<TPluginsStart>, plugins: TPluginsSetup) {
+  public async setup(setupContext: CoreSetup<TPluginsStart, TStart>, plugins: TPluginsSetup) {
     this.instance = await this.createPluginInstance();
 
     return await this.instance.setup(setupContext, plugins);
@@ -125,7 +125,7 @@ export class PluginWrapper<
 
     const startContract = await this.instance.start(startContext, plugins);
 
-    this.startDependencies$.next([startContext, plugins]);
+    this.startDependencies$.next([startContext, plugins, startContract]);
 
     return startContract;
   }

src/core/public/plugins/plugins_service.ts

@@ -53,7 +53,7 @@ export interface PluginsServiceStart {
  */
 export class PluginsService implements CoreService<PluginsServiceSetup, PluginsServiceStart> {
   /** Plugin wrappers in topological order. */
-  private readonly plugins = new Map<PluginName, PluginWrapper<unknown, Record<string, unknown>>>();
+  private readonly plugins = new Map<PluginName, PluginWrapper<unknown, unknown>>();
   private readonly pluginDependencies = new Map<PluginName, PluginName[]>();
 
   private readonly satupPlugins: PluginName[] = [];

src/core/public/public.api.md

@@ -371,7 +371,7 @@ export interface CoreContext {
 }
 
 // @public
-export interface CoreSetup<TPluginsStart extends object = object> {
+export interface CoreSetup<TPluginsStart extends object = object, TStart = unknown> {
     // (undocumented)
     application: ApplicationSetup;
     // @deprecated (undocumented)
@@ -379,7 +379,7 @@ export interface CoreSetup<TPluginsStart extends object = object> {
     // (undocumented)
     fatalErrors: FatalErrorsSetup;
     // (undocumented)
-    getStartServices: StartServicesAccessor<TPluginsStart>;
+    getStartServices: StartServicesAccessor<TPluginsStart, TStart>;
     // (undocumented)
     http: HttpSetup;
     // @deprecated
@@ -807,7 +807,7 @@ export interface IUiSettingsClient {
 }
 
 // @public @deprecated
-export interface LegacyCoreSetup extends CoreSetup<any> {
+export interface LegacyCoreSetup extends CoreSetup<any, any> {
     // Warning: (ae-forgotten-export) The symbol "InjectedMetadataSetup" needs to be exported by the entry point index.d.ts
     //
     // @deprecated (undocumented)
@@ -907,7 +907,7 @@ export interface PackageInfo {
 // @public
 export interface Plugin<TSetup = void, TStart = void, TPluginsSetup extends object = object, TPluginsStart extends object = object> {
     // (undocumented)
-    setup(core: CoreSetup<TPluginsStart>, plugins: TPluginsSetup): TSetup | Promise<TSetup>;
+    setup(core: CoreSetup<TPluginsStart, TStart>, plugins: TPluginsSetup): TSetup | Promise<TSetup>;
     // (undocumented)
     start(core: CoreStart, plugins: TPluginsStart): TStart | Promise<TStart>;
     // (undocumented)
@@ -1237,7 +1237,7 @@ export class SimpleSavedObject<T = unknown> {
 }
 
 // @public
-export type StartServicesAccessor<TPluginsStart extends object = object> = () => Promise<[CoreStart, TPluginsStart]>;
+export type StartServicesAccessor<TPluginsStart extends object = object, TStart = unknown> = () => Promise<[CoreStart, TPluginsStart, TStart]>;
 
 // @public
 export type StringValidation = StringValidationRegex | StringValidationRegexString;

src/core/server/index.ts

@@ -333,9 +333,13 @@ export interface RequestHandlerContext {
 /**
  * Context passed to the plugins `setup` method.
  *
+ * @typeParam TPluginsStart - the type of the consuming plugin's start dependencies. Should be the same
+ *                            as the consuming {@link Plugin}'s `TPluginsStart` type. Used by `getStartServices`.
+ * @typeParam TStart - the type of the consuming plugin's start contract. Should be the same as the
+ *                     consuming {@link Plugin}'s `TStart` type. Used by `getStartServices`.
  * @public
  */
-export interface CoreSetup<TPluginsStart extends object = object> {
+export interface CoreSetup<TPluginsStart extends object = object, TStart = unknown> {
   /** {@link CapabilitiesSetup} */
   capabilities: CapabilitiesSetup;
   /** {@link ContextSetup} */
@@ -353,7 +357,7 @@ export interface CoreSetup<TPluginsStart extends object = object> {
   /** {@link MetricsServiceSetup} */
   metrics: MetricsServiceSetup;
   /** {@link StartServicesAccessor} */
-  getStartServices: StartServicesAccessor<TPluginsStart>;
+  getStartServices: StartServicesAccessor<TPluginsStart, TStart>;
 }
 
 /**
@@ -364,9 +368,10 @@ export interface CoreSetup<TPluginsStart extends object = object> {
  *
  * @public
  */
-export type StartServicesAccessor<TPluginsStart extends object = object> = () => Promise<
-  [CoreStart, TPluginsStart]
->;
+export type StartServicesAccessor<
+  TPluginsStart extends object = object,
+  TStart = unknown
+> = () => Promise<[CoreStart, TPluginsStart, TStart]>;
 
 /**
  * Context passed to the plugins `start` method.

src/core/server/legacy/legacy_service.ts

@@ -312,7 +312,7 @@ export class LegacyService implements CoreService {
       uuid: {
         getInstanceUuid: setupDeps.core.uuid.getInstanceUuid,
       },
-      getStartServices: () => Promise.resolve([coreStart, startDeps.plugins]),
+      getStartServices: () => Promise.resolve([coreStart, startDeps.plugins, {}]),
     };
 
     // eslint-disable-next-line @typescript-eslint/no-var-requires

src/core/server/mocks.ts

@@ -96,7 +96,13 @@ function pluginInitializerContextMock<T>(config: T = {} as T) {
 
 type CoreSetupMockType = MockedKeys<CoreSetup> & jest.Mocked<Pick<CoreSetup, 'getStartServices'>>;
 
-function createCoreSetupMock() {
+function createCoreSetupMock({
+  pluginStartDeps = {},
+  pluginStartContract,
+}: {
+  pluginStartDeps?: object;
+  pluginStartContract?: any;
+} = {}) {
   const httpService = httpServiceMock.createSetupContract();
   const httpMock: jest.Mocked<CoreSetup['http']> = {
     createCookieSessionStorageFactory: httpService.createCookieSessionStorageFactory,
@@ -131,8 +137,8 @@ function createCoreSetupMock() {
     uuid: uuidServiceMock.createSetupContract(),
     metrics: metricsServiceMock.createSetupContract(),
     getStartServices: jest
-      .fn<Promise<[ReturnType<typeof createCoreStartMock>, object]>, []>()
-      .mockResolvedValue([createCoreStartMock(), {}]),
+      .fn<Promise<[ReturnType<typeof createCoreStartMock>, object, any]>, []>()
+      .mockResolvedValue([createCoreStartMock(), pluginStartDeps, pluginStartContract]),
   };
 
   return mock;

src/core/server/plugins/integration_tests/plugins_service.test.ts

@@ -107,7 +107,7 @@ describe('PluginsService', () => {
   });
 
   it("properly resolves `getStartServices` in plugin's lifecycle", async () => {
-    expect.assertions(5);
+    expect.assertions(6);
 
     const pluginPath = 'plugin-path';
 
@@ -125,20 +125,25 @@ describe('PluginsService', () => {
     let contextFromStart: any = null;
     let contextFromStartService: any = null;
 
+    const pluginStartContract = {
+      someApi: () => 'foo',
+    };
+
     const pluginInitializer = () =>
       ({
         setup: async (coreSetup, deps) => {
-          coreSetup.getStartServices().then(([core, plugins]) => {
+          coreSetup.getStartServices().then(([core, plugins, pluginStart]) => {
             startDependenciesResolved = true;
-            contextFromStartService = { core, plugins };
+            contextFromStartService = { core, plugins, pluginStart };
           });
         },
         start: async (core, plugins) => {
           contextFromStart = { core, plugins };
           await new Promise(resolve => setTimeout(resolve, 10));
           expect(startDependenciesResolved).toBe(false);
+          return pluginStartContract;
         },
-      } as Plugin);
+      } as Plugin<void, typeof pluginStartContract, {}, {}>);
 
     jest.doMock(
       join(pluginPath, 'server'),
@@ -163,5 +168,6 @@ describe('PluginsService', () => {
     expect(startDependenciesResolved).toBe(true);
     expect(contextFromStart!.core).toEqual(contextFromStartService!.core);
     expect(contextFromStart!.plugins).toEqual(contextFromStartService!.plugins);
+    expect(contextFromStartService!.pluginStart).toEqual(pluginStartContract);
   });
 });

src/core/server/plugins/plugin.test.ts

@@ -250,6 +250,9 @@ test("`start` resolves `startDependencies` Promise after plugin's start", async
   });
   const startContext = { any: 'thing' } as any;
   const pluginDeps = { someDep: 'value' };
+  const pluginStartContract = {
+    someApi: () => 'foo',
+  };
 
   let startDependenciesResolved = false;
 
@@ -259,6 +262,7 @@ test("`start` resolves `startDependencies` Promise after plugin's start", async
       // delay to ensure startDependencies is not resolved until after the plugin instance's start resolves.
       await new Promise(resolve => setTimeout(resolve, 10));
       expect(startDependenciesResolved).toBe(false);
+      return pluginStartContract;
     },
   };
   mockPluginInitializer.mockReturnValue(mockPluginInstance);
@@ -267,7 +271,7 @@ test("`start` resolves `startDependencies` Promise after plugin's start", async
 
   const startDependenciesCheck = plugin.startDependencies.then(resolvedStartDeps => {
     startDependenciesResolved = true;
-    expect(resolvedStartDeps).toEqual([startContext, pluginDeps]);
+    expect(resolvedStartDeps).toEqual([startContext, pluginDeps, pluginStartContract]);
   });
 
   await plugin.start(startContext, pluginDeps);

src/core/server/plugins/plugin.ts

@@ -61,7 +61,7 @@ export class PluginWrapper<
 
   private instance?: Plugin<TSetup, TStart, TPluginsSetup, TPluginsStart>;
 
-  private readonly startDependencies$ = new Subject<[CoreStart, TPluginsStart]>();
+  private readonly startDependencies$ = new Subject<[CoreStart, TPluginsStart, TStart]>();
   public readonly startDependencies = this.startDependencies$.pipe(first()).toPromise();
 
   constructor(
@@ -115,7 +115,7 @@ export class PluginWrapper<
     this.log.debug('Starting plugin');
 
     const startContract = await this.instance.start(startContext, plugins);
-    this.startDependencies$.next([startContext, plugins]);
+    this.startDependencies$.next([startContext, plugins, startContract]);
     return startContract;
   }
 

src/core/server/server.api.md

@@ -622,7 +622,7 @@ export interface ContextSetup {
 export type CoreId = symbol;
 
 // @public
-export interface CoreSetup<TPluginsStart extends object = object> {
+export interface CoreSetup<TPluginsStart extends object = object, TStart = unknown> {
     // (undocumented)
     capabilities: CapabilitiesSetup;
     // (undocumented)
@@ -630,7 +630,7 @@ export interface CoreSetup<TPluginsStart extends object = object> {
     // (undocumented)
     elasticsearch: ElasticsearchServiceSetup;
     // (undocumented)
-    getStartServices: StartServicesAccessor<TPluginsStart>;
+    getStartServices: StartServicesAccessor<TPluginsStart, TStart>;
     // (undocumented)
     http: HttpServiceSetup;
     // (undocumented)
@@ -2270,7 +2270,7 @@ export type SharedGlobalConfig = RecursiveReadonly_2<{
 }>;
 
 // @public
-export type StartServicesAccessor<TPluginsStart extends object = object> = () => Promise<[CoreStart, TPluginsStart]>;
+export type StartServicesAccessor<TPluginsStart extends object = object, TStart = unknown> = () => Promise<[CoreStart, TPluginsStart, TStart]>;
 
 // @public
 export type StringValidation = StringValidationRegex | StringValidationRegexString;

src/legacy/core_plugins/input_control_vis/public/plugin.ts

@@ -24,7 +24,7 @@ import { VisualizationsSetup, VisualizationsStart } from '../../visualizations/p
 import { createInputControlVisFn } from './input_control_fn';
 import { createInputControlVisTypeDefinition } from './input_control_vis_type';
 
-type InputControlVisCoreSetup = CoreSetup<InputControlVisPluginStartDependencies>;
+type InputControlVisCoreSetup = CoreSetup<InputControlVisPluginStartDependencies, void>;
 
 export interface InputControlVisDependencies {
   core: InputControlVisCoreSetup;
@@ -46,7 +46,7 @@ export interface InputControlVisPluginStartDependencies {
 }
 
 /** @internal */
-export class InputControlVisPlugin implements Plugin<Promise<void>, void> {
+export class InputControlVisPlugin implements Plugin<void, void> {
   constructor(public initializerContext: PluginInitializerContext) {}
 
   public async setup(

src/legacy/core_plugins/kibana/public/discover/plugin.ts

@@ -91,7 +91,7 @@ export class DiscoverPlugin implements Plugin<void, void> {
   public initializeInnerAngular?: () => void;
   public initializeServices?: () => Promise<{ core: CoreStart; plugins: DiscoverStartPlugins }>;
 
-  setup(core: CoreSetup<DiscoverStartPlugins>, plugins: DiscoverSetupPlugins) {
+  setup(core: CoreSetup<DiscoverStartPlugins, void>, plugins: DiscoverSetupPlugins) {
     const { appMounted, appUnMounted, stop: stopUrlTracker } = createKbnUrlTracker({
       baseUrl: core.http.basePath.prepend('/app/kibana'),
       defaultSubUrl: '#/discover',

src/legacy/core_plugins/vis_type_timelion/public/plugin.ts

@@ -35,7 +35,7 @@ import { getTimelionVisualizationConfig } from './timelion_vis_fn';
 import { getTimelionVisDefinition } from './timelion_vis_type';
 import { setIndexPatterns, setSavedObjectsClient } from './helpers/plugin_services';
 
-type TimelionVisCoreSetup = CoreSetup<TimelionVisSetupDependencies>;
+type TimelionVisCoreSetup = CoreSetup<TimelionVisSetupDependencies, void>;
 
 /** @internal */
 export interface TimelionVisDependencies extends Partial<CoreStart> {

src/legacy/core_plugins/vis_type_vislib/public/plugin.ts

@@ -62,10 +62,10 @@ export interface VisTypeVislibPluginStartDependencies {
   data: DataPublicPluginStart;
 }
 
-type VisTypeVislibCoreSetup = CoreSetup<VisTypeVislibPluginStartDependencies>;
+type VisTypeVislibCoreSetup = CoreSetup<VisTypeVislibPluginStartDependencies, void>;
 
 /** @internal */
-export class VisTypeVislibPlugin implements Plugin<Promise<void>, void> {
+export class VisTypeVislibPlugin implements Plugin<void, void> {
   constructor(public initializerContext: PluginInitializerContext) {}
 
   public async setup(

src/legacy/core_plugins/vis_type_xy/public/plugin.ts

@@ -47,10 +47,10 @@ export interface VisTypeXyPluginStartDependencies {
   visualizations: VisualizationsStart;
 }
 
-type VisTypeXyCoreSetup = CoreSetup<VisTypeXyPluginStartDependencies>;
+type VisTypeXyCoreSetup = CoreSetup<VisTypeXyPluginStartDependencies, void>;
 
 /** @internal */
-export class VisTypeXyPlugin implements Plugin<Promise<void>, void> {
+export class VisTypeXyPlugin implements Plugin<void, void> {
   constructor(public initializerContext: PluginInitializerContext) {}
 
   public async setup(

src/plugins/home/public/plugin.ts

@@ -50,7 +50,9 @@ export interface HomePluginSetupDependencies {
   kibanaLegacy: KibanaLegacySetup;
 }
 
-export class HomePublicPlugin implements Plugin<HomePublicPluginSetup, void> {
+export class HomePublicPlugin
+  implements
+    Plugin<HomePublicPluginSetup, void, HomePluginSetupDependencies, HomePluginStartDependencies> {
   private readonly featuresCatalogueRegistry = new FeatureCatalogueRegistry();
   private readonly environmentService = new EnvironmentService();
   private readonly tutorialService = new TutorialService();

x-pack/plugins/actions/server/plugin.ts

@@ -175,7 +175,7 @@ export class ActionsPlugin implements Plugin<Promise<PluginSetupContract>, Plugi
 
     const usageCollection = plugins.usageCollection;
     if (usageCollection) {
-      core.getStartServices().then(async ([coreStart, startPlugins]: [CoreStart, any]) => {
+      core.getStartServices().then(async ([, startPlugins]: [CoreStart, any, any]) => {
         registerActionsUsageCollector(usageCollection, startPlugins.taskManager);
 
         initializeActionsTelemetry(

x-pack/plugins/alerting/server/plugin.ts

@@ -143,7 +143,7 @@ export class AlertingPlugin {
 
     const usageCollection = plugins.usageCollection;
     if (usageCollection) {
-      core.getStartServices().then(async ([coreStart, startPlugins]: [CoreStart, any]) => {
+      core.getStartServices().then(async ([, startPlugins]: [CoreStart, any, any]) => {
         registerAlertsUsageCollector(usageCollection, startPlugins.taskManager);
 
         initializeAlertingTelemetry(

x-pack/plugins/ingest_manager/public/plugin.ts

@@ -32,7 +32,9 @@ export interface IngestManagerStartDeps {
   data: DataPublicPluginStart;
 }
 
-export class IngestManagerPlugin implements Plugin {
+export class IngestManagerPlugin
+  implements
+    Plugin<IngestManagerSetup, IngestManagerStart, IngestManagerSetupDeps, IngestManagerStartDeps> {
   private config: IngestManagerConfigType;
 
   constructor(private readonly initializerContext: PluginInitializerContext) {
@@ -50,7 +52,8 @@ export class IngestManagerPlugin implements Plugin {
       async mount(params: AppMountParameters) {
         const [coreStart, startDeps] = (await core.getStartServices()) as [
           CoreStart,
-          IngestManagerStartDeps
+          IngestManagerStartDeps,
+          IngestManagerStart
         ];
         const { renderApp } = await import('./applications/ingest_manager');
         return renderApp(coreStart, params, deps, startDeps, config);

x-pack/plugins/ml/public/index.ts

@@ -6,8 +6,19 @@
 
 import { PluginInitializer } from 'kibana/public';
 import './index.scss';
-import { MlPlugin, MlPluginSetup, MlPluginStart } from './plugin';
+import {
+  MlPlugin,
+  MlPluginSetup,
+  MlPluginStart,
+  MlSetupDependencies,
+  MlStartDependencies,
+} from './plugin';
 
-export const plugin: PluginInitializer<MlPluginSetup, MlPluginStart> = () => new MlPlugin();
+export const plugin: PluginInitializer<
+  MlPluginSetup,
+  MlPluginStart,
+  MlSetupDependencies,
+  MlStartDependencies
+> = () => new MlPlugin();
 
 export { MlPluginSetup, MlPluginStart };

x-pack/plugins/ml/public/plugin.ts

@@ -31,7 +31,7 @@ export interface MlSetupDependencies {
 }
 
 export class MlPlugin implements Plugin<MlPluginSetup, MlPluginStart> {
-  setup(core: CoreSetup<MlStartDependencies>, pluginsSetup: MlSetupDependencies) {
+  setup(core: CoreSetup<MlStartDependencies, MlPluginStart>, pluginsSetup: MlSetupDependencies) {
     core.application.register({
       id: PLUGIN_ID,
       title: i18n.translate('xpack.ml.plugin.title', {

x-pack/plugins/monitoring/server/plugin.ts

@@ -224,7 +224,7 @@ export class Plugin {
       this.monitoringCore = this.getLegacyShim(
         config,
         legacyConfig,
-        core.getStartServices as () => Promise<[CoreStart, PluginsStart]>,
+        core.getStartServices as () => Promise<[CoreStart, PluginsStart, {}]>,
         this.licenseService,
         this.cluster
       );
@@ -293,7 +293,7 @@ export class Plugin {
   getLegacyShim(
     config: MonitoringConfig,
     legacyConfig: any,
-    getCoreServices: () => Promise<[CoreStart, PluginsStart]>,
+    getCoreServices: () => Promise<[CoreStart, PluginsStart, {}]>,
     licenseService: MonitoringLicenseService,
     cluster: ICustomClusterClient
   ): MonitoringCore {

x-pack/plugins/security/public/account_management/account_management_app.test.ts

@@ -38,7 +38,7 @@ describe('accountManagementApp', () => {
   it('properly sets breadcrumbs and renders application', async () => {
     const coreSetupMock = coreMock.createSetup();
     const coreStartMock = coreMock.createStart();
-    coreSetupMock.getStartServices.mockResolvedValue([coreStartMock, {}]);
+    coreSetupMock.getStartServices.mockResolvedValue([coreStartMock, {}, {}]);
 
     const authcMock = securityMock.createSetup().authc;
     const containerMock = document.createElement('div');

x-pack/plugins/security/public/authentication/logged_out/logged_out_app.test.ts

@@ -35,7 +35,7 @@ describe('loggedOutApp', () => {
   it('properly renders application', async () => {
     const coreSetupMock = coreMock.createSetup();
     const coreStartMock = coreMock.createStart();
-    coreSetupMock.getStartServices.mockResolvedValue([coreStartMock, {}]);
+    coreSetupMock.getStartServices.mockResolvedValue([coreStartMock, {}, {}]);
 
     const containerMock = document.createElement('div');
 

x-pack/plugins/security/public/authentication/login/login_app.test.ts

@@ -38,7 +38,7 @@ describe('loginApp', () => {
   it('properly renders application', async () => {
     const coreSetupMock = coreMock.createSetup();
     const coreStartMock = coreMock.createStart();
-    coreSetupMock.getStartServices.mockResolvedValue([coreStartMock, {}]);
+    coreSetupMock.getStartServices.mockResolvedValue([coreStartMock, {}, {}]);
     const containerMock = document.createElement('div');
 
     loginApp.create({

x-pack/plugins/security/public/authentication/overwritten_session/overwritten_session_app.test.ts

@@ -37,7 +37,7 @@ describe('overwrittenSessionApp', () => {
   it('properly sets breadcrumbs and renders application', async () => {
     const coreSetupMock = coreMock.createSetup();
     const coreStartMock = coreMock.createStart();
-    coreSetupMock.getStartServices.mockResolvedValue([coreStartMock, {}]);
+    coreSetupMock.getStartServices.mockResolvedValue([coreStartMock, {}, {}]);
 
     const authcMock = securityMock.createSetup().authc;
     const containerMock = document.createElement('div');

x-pack/plugins/security/public/index.ts

@@ -6,13 +6,22 @@
 
 import './index.scss';
 import { PluginInitializer, PluginInitializerContext } from 'src/core/public';
-import { SecurityPlugin, SecurityPluginSetup, SecurityPluginStart } from './plugin';
+import {
+  SecurityPlugin,
+  SecurityPluginSetup,
+  SecurityPluginStart,
+  PluginSetupDependencies,
+  PluginStartDependencies,
+} from './plugin';
 
 export { SecurityPluginSetup, SecurityPluginStart };
 export { SessionInfo } from './types';
 export { AuthenticatedUser } from '../common/model';
 export { SecurityLicense, SecurityLicenseFeatures } from '../common/licensing';
 
-export const plugin: PluginInitializer<SecurityPluginSetup, SecurityPluginStart> = (
-  initializerContext: PluginInitializerContext
-) => new SecurityPlugin(initializerContext);
+export const plugin: PluginInitializer<
+  SecurityPluginSetup,
+  SecurityPluginStart,
+  PluginSetupDependencies,
+  PluginStartDependencies
+> = (initializerContext: PluginInitializerContext) => new SecurityPlugin(initializerContext);

x-pack/plugins/spaces/public/management/spaces_management_app.test.tsx

@@ -51,7 +51,7 @@ async function mountApp(basePath: string, spaceId?: string) {
     .create({
       spacesManager,
       securityLicense,
-      getStartServices: async () => [coreStart, pluginsStart as PluginsStart],
+      getStartServices: async () => [coreStart, pluginsStart as PluginsStart, {}],
     })
     .mount({ basePath, element: container, setBreadcrumbs });
 

x-pack/plugins/spaces/server/capabilities/capabilities_switcher.test.ts

@@ -103,6 +103,7 @@ const setup = (space: Space) => {
   coreSetup.getStartServices.mockResolvedValue([
     coreMock.createStart(),
     { features: featuresStart },
+    {},
   ]);
 
   const spacesService = spacesServiceMock.createSetupContract();

x-pack/test/plugin_functional/plugins/resolver_test/public/index.ts

@@ -5,6 +5,15 @@
  */
 
 import { PluginInitializer } from 'kibana/public';
-import { ResolverTestPlugin } from './plugin';
+import {
+  ResolverTestPlugin,
+  ResolverTestPluginSetupDependencies,
+  ResolverTestPluginStartDependencies,
+} from './plugin';
 
-export const plugin: PluginInitializer<void, void> = () => new ResolverTestPlugin();
+export const plugin: PluginInitializer<
+  void,
+  void,
+  ResolverTestPluginSetupDependencies,
+  ResolverTestPluginStartDependencies
+> = () => new ResolverTestPlugin();