add licence checker wrapper

x-pack/plugins/licensing/common/licensing.mock.ts

@@ -53,6 +53,7 @@ const createLicenseMock = () => {
   };
   mock.check.mockReturnValue({ state: 'valid' });
   mock.hasAtLeast.mockReturnValue(true);
+  mock.getFeature.mockReturnValue({ isAvailable: true, isEnabled: true });
   return mock;
 };
 export const licenseMock = {

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

@@ -12,3 +12,7 @@ export const plugin = (context: PluginInitializerContext) => new LicensingPlugin
 export * from '../common/types';
 export * from './types';
 export { config } from './licensing_config';
+export {
+  CheckLicense,
+  licenseCheckerRouteHandlerWrapper,
+} from './license_checker_route_handler_wrapper';

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

@@ -0,0 +1,40 @@
+/*
+ * 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 {
+  RequestHandler,
+  RequestHandlerContext,
+  KibanaRequest,
+  RouteMethod,
+  KibanaResponseFactory,
+} from 'src/core/server';
+
+import { ILicense } from '../common/types';
+
+export type CheckLicense = (
+  license: ILicense
+) => { valid: false; message: string } | { valid: true; message: null };
+
+export function licenseCheckerRouteHandlerWrapper<P, Q, B>(
+  checkLicense: CheckLicense,
+  handler: RequestHandler<P, Q, B>
+): RequestHandler<P, Q, B> {
+  return async (
+    context: RequestHandlerContext,
+    request: KibanaRequest<P, Q, B, RouteMethod>,
+    response: KibanaResponseFactory
+  ) => {
+    const licenseCheckResult = checkLicense(context.licensing.license);
+
+    if (licenseCheckResult.valid) {
+      return handler(context, request, response);
+    } else {
+      return response.forbidden({
+        body: licenseCheckResult.message,
+      });
+    }
+  };
+}

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

@@ -0,0 +1,59 @@
+/*
+ * 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 { httpServerMock } from 'src/core/server/mocks';
+
+import {
+  licenseCheckerRouteHandlerWrapper,
+  CheckLicense,
+} from './license_checker_route_handler_wrapper';
+
+const context = {
+  licensing: {
+    license: {},
+  },
+} as any;
+const request = httpServerMock.createKibanaRequest();
+
+describe('licenseCheckerRouteHandlerWrapper', () => {
+  it('calls route handler if checkLicense returns "valid": true', async () => {
+    const checkLicense: CheckLicense = () => ({ valid: true, message: null });
+    const routeHandler = jest.fn();
+    const wrapper = licenseCheckerRouteHandlerWrapper(checkLicense, routeHandler);
+    const response = httpServerMock.createResponseFactory();
+
+    await wrapper(context, request, response);
+
+    expect(routeHandler).toHaveBeenCalledTimes(1);
+    expect(routeHandler).toHaveBeenCalledWith(context, request, response);
+  });
+
+  it('does not call route handler if checkLicense returns "valid": false', async () => {
+    const checkLicense: CheckLicense = () => ({ valid: false, message: 'reason' });
+    const routeHandler = jest.fn();
+    const wrapper = licenseCheckerRouteHandlerWrapper(checkLicense, routeHandler);
+    const response = httpServerMock.createResponseFactory();
+
+    await wrapper(context, request, response);
+
+    expect(routeHandler).toHaveBeenCalledTimes(0);
+    expect(response.forbidden).toHaveBeenCalledTimes(1);
+    expect(response.forbidden).toHaveBeenCalledWith({ body: 'reason' });
+  });
+
+  it('allows an exception to bubble up if handler throws', async () => {
+    const checkLicense: CheckLicense = () => ({ valid: true, message: null });
+    const routeHandler = () => {
+      throw new Error('reason');
+    };
+    const wrapper = licenseCheckerRouteHandlerWrapper(checkLicense, routeHandler);
+    const response = httpServerMock.createResponseFactory();
+
+    await expect(wrapper(context, request, response)).rejects.toThrowErrorMatchingInlineSnapshot(
+      `"reason"`
+    );
+  });
+});