NP Licensing plugin route handler context (#46586)

* introducing a licensing route handler context

* extracting route handler context for easier testing

* address PR feedback

x-pack/plugins/licensing/server/licensing_route_handler_context.test.ts

@@ -0,0 +1,36 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { BehaviorSubject } from 'rxjs';
+import { ILicense } from './types';
+import { setup } from './__fixtures__/setup';
+import { createRouteHandlerContext } from './licensing_route_handler_context';
+
+describe('licensingRouteHandlerContext', () => {
+  it('provides the initial license value', async () => {
+    const { license$, license } = await setup();
+
+    const context = createRouteHandlerContext(license$);
+
+    const { license: contextResult } = await context({});
+
+    expect(contextResult).toBe(license);
+  });
+
+  it('provides the latest license value', async () => {
+    const { license } = await setup();
+    const license$ = new BehaviorSubject<ILicense>(license);
+
+    const context = createRouteHandlerContext(license$);
+
+    const latestLicense = (Symbol() as unknown) as ILicense;
+    license$.next(latestLicense);
+
+    const { license: contextResult } = await context({});
+
+    expect(contextResult).toBe(latestLicense);
+  });
+});

x-pack/plugins/licensing/server/licensing_route_handler_context.ts

@@ -0,0 +1,19 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { RequestHandlerContext, IContextProvider } from 'src/core/server';
+import { Observable } from 'rxjs';
+import { take } from 'rxjs/operators';
+import { ILicense } from './types';
+
+export function createRouteHandlerContext(
+  license$: Observable<ILicense>
+): IContextProvider<RequestHandlerContext, 'licensing'> {
+  return async function licensingRouteHandlerContext() {
+    const license = await license$.pipe(take(1)).toPromise();
+    return { license };
+  };
+}

x-pack/plugins/licensing/server/plugin.test.ts

@@ -80,4 +80,21 @@ describe('licensing plugin', () => {
 
     expect(licenseTypes).toEqual(['basic', 'gold', 'platinum']);
   });
+
+  test('provides a licensing context to http routes', async () => {
+    const { coreSetup, plugin: _plugin } = await setupOnly();
+
+    plugin = _plugin;
+
+    await plugin.setup(coreSetup);
+
+    expect(coreSetup.http.registerRouteHandlerContext.mock.calls).toMatchInlineSnapshot(`
+      Array [
+        Array [
+          "licensing",
+          [Function],
+        ],
+      ]
+    `);
+  });
 });

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

@@ -18,6 +18,7 @@ import { Poller } from '../../../../src/core/utils/poller';
 import { LicensingConfigType, LicensingPluginSetup, ILicense } from './types';
 import { LicensingConfig } from './licensing_config';
 import { License } from './license';
+import { createRouteHandlerContext } from './licensing_route_handler_context';
 
 export class Plugin implements CorePlugin<LicensingPluginSetup> {
   private readonly logger: Logger;
@@ -120,9 +121,12 @@ export class Plugin implements CorePlugin<LicensingPluginSetup> {
   public async setup(core: CoreSetup) {
     const config = await this.config$.pipe(first()).toPromise();
     const poller = this.create(config, core);
+    const license$ = poller.subject$.asObservable();
+
+    core.http.registerRouteHandlerContext('licensing', createRouteHandlerContext(license$));
 
     return {
-      license$: poller.subject$.asObservable(),
+      license$,
     };
   }
 

x-pack/plugins/licensing/server/types.ts

@@ -118,3 +118,14 @@ export type LicensingConfigType = TypeOf<typeof schema>;
 export type LicenseType = keyof typeof LICENSE_TYPE;
 /** @public */
 export type LicenseFeatureSerializer = (licensing: ILicense) => any;
+
+/** @public */
+export interface LicensingRequestContext {
+  license: ILicense;
+}
+
+declare module 'src/core/server' {
+  interface RequestHandlerContext {
+    licensing: LicensingRequestContext;
+  }
+}