[New platform]Expose NP core services to the legacy UI (#32480)

* Expose NP core services to the legacy UI

* declare start/stop explicitly

* simplify typings + renaming

src/core/public/legacy/legacy_service.ts

@@ -54,18 +54,20 @@ export interface LegacyPlatformParams {
 export class LegacyPlatformService {
   constructor(private readonly params: LegacyPlatformParams) {}
 
-  public start({
-    i18n,
-    injectedMetadata,
-    fatalErrors,
-    notifications,
-    http,
-    basePath,
-    uiSettings,
-    chrome,
-  }: Deps) {
+  public start(deps: Deps) {
+    const {
+      i18n,
+      injectedMetadata,
+      fatalErrors,
+      notifications,
+      http,
+      basePath,
+      uiSettings,
+      chrome,
+    } = deps;
     // Inject parts of the new platform into parts of the legacy platform
     // so that legacy APIs/modules can mimic their new platform counterparts
+    require('ui/new_platform').__newPlatformInit__(deps);
     require('ui/metadata').__newPlatformInit__(injectedMetadata.getLegacyMetadata());
     require('ui/i18n').__newPlatformInit__(i18n.Context);
     require('ui/notify/fatal_error').__newPlatformInit__(fatalErrors);

src/legacy/ui/public/new_platform/index.ts

@@ -0,0 +1,19 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+export { __newPlatformInit__, getNewPlatform } from './new_platform';

src/legacy/ui/public/new_platform/new_platform.ts

@@ -0,0 +1,57 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { BasePathStart } from '../../../../core/public/base_path';
+import { ChromeStart } from '../../../../core/public/chrome';
+import { FatalErrorsStart } from '../../../../core/public/fatal_errors';
+import { HttpStart } from '../../../../core/public/http';
+import { I18nStart } from '../../../../core/public/i18n';
+import { InjectedMetadataStart } from '../../../../core/public/injected_metadata';
+import { NotificationsStart } from '../../../../core/public/notifications';
+import { UiSettingsClient } from '../../../../core/public/ui_settings';
+
+interface CoreStart {
+  i18n: I18nStart;
+  injectedMetadata: InjectedMetadataStart;
+  fatalErrors: FatalErrorsStart;
+  notifications: NotificationsStart;
+  http: HttpStart;
+  basePath: BasePathStart;
+  uiSettings: UiSettingsClient;
+  chrome: ChromeStart;
+}
+
+const runtimeContext = {
+  start: {
+    core: null as CoreStart | null,
+    plugins: {},
+  },
+};
+
+export function __newPlatformInit__(core: CoreStart) {
+  if (runtimeContext.start.core) {
+    throw new Error('New platform core api was already initialized');
+  }
+
+  runtimeContext.start.core = core;
+}
+
+export function getNewPlatform() {
+  return runtimeContext;
+}