feat(rest): expose app.requestHandler function

Each RestServer provides an HTTP handler function that can be used
with the core HTTP server or any compatible framework like Express.

This change exposes the handler function on the RestApplication class
to simplify the usage.

BREAKING CHANGE: `RestServer#handleHttp` was renamed to
`RestServer#requestHandler`.

Author: bajtos

packages/authentication/test/acceptance/basic-auth.ts

@@ -188,7 +188,7 @@ describe('Basic Authentication', () => {
   }
 
   function whenIMakeRequestTo(restServer: RestServer): Client {
-    return createClientForHandler(restServer.handleHttp);
+    return createClientForHandler(restServer.requestHandler);
   }
 });
 

packages/boot/test/acceptance/controller.booter.acceptance.ts

@@ -23,7 +23,7 @@ describe('controller booter acceptance tests', () => {
     await app.start();
 
     const server: RestServer = await app.getServer(RestServer);
-    const client: Client = createClientForHandler(server.handleHttp);
+    const client: Client = createClientForHandler(server.requestHandler);
 
     // Default Controllers = /controllers with .controller.js ending (nested = true);
     await client.get('/one').expect(200, 'ControllerOne.one()');

packages/cli/generators/app/templates/test/ping.controller.test.ts.ejs

@@ -17,7 +17,7 @@ describe('PingController', () => {
   });
 
   before(() => {
-    client = createClientForHandler(server.handleHttp);
+    client = createClientForHandler(server.requestHandler);
   });
 
   after(async () => {

packages/cli/test/app-run.test.js

@@ -11,7 +11,7 @@ const helpers = require('yeoman-test');
 const lerna = require('lerna');
 const build = require('@loopback/build');
 
-describe('app-generator', function() {
+describe('app-generator (SLOW)', function() {
   const generator = path.join(__dirname, '../generators/app');
   const rootDir = path.join(__dirname, '../../..');
   const sandbox = path.join(__dirname, '../../_sandbox');

packages/example-getting-started/test/acceptance/application.test.ts

@@ -19,7 +19,7 @@ describe('Application', () => {
   before(givenARestServer);
   before(givenTodoRepository);
   before(() => {
-    client = createClientForHandler(server.handleHttp);
+    client = createClientForHandler(server.requestHandler);
   });
   after(async () => {
     await app.stop();

packages/example-log-extension/test/acceptance/log.extension.acceptance.ts

@@ -5,7 +5,6 @@
 
 import {
   RestApplication,
-  RestServer,
   SequenceHandler,
   RestBindings,
   FindRoute,
@@ -42,7 +41,6 @@ import {logToMemory, resetLogs} from '../in-memory-logger';
 
 describe('log extension acceptance test', () => {
   let app: LogApp;
-  let server: RestServer;
   let spy: SinonSpy;
 
   class LogApp extends LogMixin(RestApplication) {}
@@ -73,7 +71,7 @@ describe('log extension acceptance test', () => {
 
   it('logs information at DEBUG or higher', async () => {
     setAppLogToDebug();
-    const client: Client = createClientForHandler(server.handleHttp);
+    const client: Client = createClientForHandler(app.requestHandler);
 
     await client.get('/nolog').expect(200, 'nolog called');
     expect(spy.called).to.be.False();
@@ -99,7 +97,7 @@ describe('log extension acceptance test', () => {
 
   it('logs information at INFO or higher', async () => {
     setAppLogToInfo();
-    const client: Client = createClientForHandler(server.handleHttp);
+    const client: Client = createClientForHandler(app.requestHandler);
 
     await client.get('/nolog').expect(200, 'nolog called');
     expect(spy.called).to.be.False();
@@ -125,7 +123,7 @@ describe('log extension acceptance test', () => {
 
   it('logs information at WARN or higher', async () => {
     setAppLogToWarn();
-    const client: Client = createClientForHandler(server.handleHttp);
+    const client: Client = createClientForHandler(app.requestHandler);
 
     await client.get('/nolog').expect(200, 'nolog called');
     expect(spy.called).to.be.False();
@@ -151,7 +149,7 @@ describe('log extension acceptance test', () => {
 
   it('logs information at ERROR', async () => {
     setAppLogToError();
-    const client: Client = createClientForHandler(server.handleHttp);
+    const client: Client = createClientForHandler(app.requestHandler);
 
     await client.get('/nolog').expect(200, 'nolog called');
     expect(spy.called).to.be.False();
@@ -177,7 +175,7 @@ describe('log extension acceptance test', () => {
 
   it('logs no information when logLevel is set to OFF', async () => {
     setAppLogToOff();
-    const client: Client = createClientForHandler(server.handleHttp);
+    const client: Client = createClientForHandler(app.requestHandler);
 
     await client.get('/nolog').expect(200, 'nolog called');
     expect(spy.called).to.be.False();
@@ -234,14 +232,13 @@ describe('log extension acceptance test', () => {
       }
     }
 
-    server.sequence(LogSequence);
+    app.sequence(LogSequence);
   }
 
   async function createApp() {
     app = new LogApp();
     app.bind(EXAMPLE_LOG_BINDINGS.TIMER).to(timer);
     app.bind(EXAMPLE_LOG_BINDINGS.LOGGER).to(logToMemory);
-    server = await app.getServer(RestServer);
   }
 
   function setAppLogToDebug() {

packages/rest/src/rest-application.ts

@@ -9,7 +9,7 @@ import {SequenceHandler, SequenceFunction} from './sequence';
 import {Binding, Constructor} from '@loopback/context';
 import {format} from 'util';
 import {RestBindings} from './keys';
-import {RouteEntry, RestServer} from '.';
+import {RouteEntry, RestServer, HttpRequestListener, HttpServerLike} from '.';
 import {ControllerClass} from './router/routing-table';
 import {OperationObject, OpenApiSpec} from '@loopback/openapi-v3-types';
 
@@ -28,7 +28,37 @@ export const SequenceActions = RestBindings.SequenceActions;
  * will throw an error.
  *
  */
-export class RestApplication extends Application {
+export class RestApplication extends Application implements HttpServerLike {
+  /**
+   * The main REST server instance providing REST API for this application.
+   */
+  get restServer(): RestServer {
+    // FIXME(kjdelisle): I attempted to mimic the pattern found in RestServer
+    // with no success, so until I've got a better way, this is functional.
+    return this.getSync<RestServer>('servers.RestServer');
+  }
+
+  /**
+   * Handle incoming HTTP(S) request by invoking the corresponding
+   * Controller method via the configured Sequence.
+   *
+   * @example
+   *
+   * ```ts
+   * const app = new RestApplication();
+   * // setup controllers, etc.
+   *
+   * const server = http.createServer(app.requestHandler);
+   * server.listen(3000);
+   * ```
+   *
+   * @param req The request.
+   * @param res The response.
+   */
+  get requestHandler(): HttpRequestListener {
+    return this.restServer.requestHandler;
+  }
+
   constructor(config?: ApplicationConfig) {
     const cfg = Object.assign({}, config);
     super(cfg);
@@ -47,10 +77,7 @@ export class RestApplication extends Application {
   }
 
   handler(handlerFn: SequenceFunction) {
-    // FIXME(kjdelisle): I attempted to mimic the pattern found in RestServer
-    // with no success, so until I've got a better way, this is functional.
-    const server: RestServer = this.getSync('servers.RestServer');
-    server.handler(handlerFn);
+    this.restServer.handler(handlerFn);
   }
 
   /**
@@ -101,8 +128,7 @@ export class RestApplication extends Application {
     controller?: ControllerClass,
     methodName?: string,
   ): Binding {
-    // FIXME(bajtos): This is a workaround based on app.handler() above
-    const server: RestServer = this.getSync('servers.RestServer');
+    const server = this.restServer;
     if (typeof routeOrVerb === 'object') {
       return server.route(routeOrVerb);
     } else {

packages/rest/src/rest-server.ts

@@ -26,6 +26,15 @@ import {
 import {ControllerClass} from './router/routing-table';
 import {RestBindings} from './keys';
 
+export type HttpRequestListener = (
+  req: ServerRequest,
+  res: ServerResponse,
+) => void;
+
+export interface HttpServerLike {
+  requestHandler: HttpRequestListener;
+}
+
 const SequenceActions = RestBindings.SequenceActions;
 
 // NOTE(bajtos) we cannot use `import * as cloneDeep from 'lodash/cloneDeep'
@@ -80,7 +89,7 @@ const OPENAPI_SPEC_MAPPING: {[key: string]: OpenApiSpecOptions} = {
  * @extends {Context}
  * @implements {Server}
  */
-export class RestServer extends Context implements Server {
+export class RestServer extends Context implements Server, HttpServerLike {
   /**
    * Handle incoming HTTP(S) request by invoking the corresponding
    * Controller method via the configured Sequence.
@@ -89,16 +98,18 @@ export class RestServer extends Context implements Server {
    *
    * ```ts
    * const app = new Application();
+   * app.component(RestComponent);
    * // setup controllers, etc.
    *
-   * const server = http.createServer(app.handleHttp);
-   * server.listen(3000);
+   * const restServer = await app.getServer(RestServer);
+   * const httpServer = http.createServer(restServer.requestHandler);
+   * httpServer.listen(3000);
    * ```
    *
    * @param req The request.
    * @param res The response.
    */
-  public handleHttp: (req: ServerRequest, res: ServerResponse) => void;
+  public requestHandler: HttpRequestListener;
 
   protected _httpHandler: HttpHandler;
   protected get httpHandler(): HttpHandler {
@@ -140,7 +151,7 @@ export class RestServer extends Context implements Server {
       this.sequence(options.sequence);
     }
 
-    this.handleHttp = (req: ServerRequest, res: ServerResponse) => {
+    this.requestHandler = (req: ServerRequest, res: ServerResponse) => {
       try {
         this._handleHttpRequest(req, res, options!).catch(err =>
           this._onUnhandledError(req, res, err),
@@ -540,7 +551,7 @@ export class RestServer extends Context implements Server {
 
     const httpPort = await this.get<number>(RestBindings.PORT);
     const httpHost = await this.get<string | undefined>(RestBindings.HOST);
-    this._httpServer = createServer(this.handleHttp);
+    this._httpServer = createServer(this.requestHandler);
     const httpServer = this._httpServer;
 
     // TODO(bajtos) support httpHostname too

packages/rest/test/acceptance/routing/routing.acceptance.ts

@@ -12,6 +12,7 @@ import {
   RestComponent,
   RestApplication,
   SequenceActions,
+  HttpServerLike,
 } from '../../..';
 
 import {api, get, post, param, requestBody} from '@loopback/openapi-v3';
@@ -552,9 +553,9 @@ describe('Routing', () => {
       const route = new Route('get', '/greet', routeSpec, greet);
       app.route(route);
 
-      const server = await givenAServer(app);
-      const client = whenIMakeRequestTo(server);
-      await client.get('/greet?name=world').expect(200, 'hello world');
+      await whenIMakeRequestTo(app)
+        .get('/greet?name=world')
+        .expect(200, 'hello world');
     });
 
     it('supports controller routes declared via app.api()', async () => {
@@ -580,9 +581,9 @@ describe('Routing', () => {
       app.api(spec);
       app.controller(MyController);
 
-      const server = await givenAServer(app);
-      const client = whenIMakeRequestTo(server);
-      await client.get('/greet?name=world').expect(200, 'hello world');
+      await whenIMakeRequestTo(app)
+        .get('/greet?name=world')
+        .expect(200, 'hello world');
     });
 
     it('supports controller routes defined via app.route()', async () => {
@@ -600,9 +601,18 @@ describe('Routing', () => {
 
       app.route('get', '/greet', spec, MyController, 'greet');
 
-      const server = await givenAServer(app);
-      const client = whenIMakeRequestTo(server);
-      await client.get('/greet?name=world').expect(200, 'hello world');
+      await whenIMakeRequestTo(app)
+        .get('/greet?name=world')
+        .expect(200, 'hello world');
+    });
+
+    it('provides httpHandler compatible with HTTP server API', async () => {
+      const app = new RestApplication();
+      app.handler((sequence, req, res) => res.end('hello'));
+
+      await createClientForHandler(app.requestHandler)
+        .get('/')
+        .expect(200, 'hello');
     });
   });
 
@@ -631,7 +641,7 @@ describe('Routing', () => {
     app.controller(controller);
   }
 
-  function whenIMakeRequestTo(server: RestServer): Client {
-    return createClientForHandler(server.handleHttp);
+  function whenIMakeRequestTo(serverOrApp: HttpServerLike): Client {
+    return createClientForHandler(serverOrApp.requestHandler);
   }
 });

packages/rest/test/acceptance/sequence/sequence.acceptance.ts

@@ -17,6 +17,7 @@ import {
   RestServer,
   RestComponent,
   RestApplication,
+  HttpServerLike,
 } from '../../..';
 import {api} from '@loopback/openapi-v3';
 import {Application} from '@loopback/core';
@@ -104,8 +105,7 @@ describe('Sequence', () => {
     const restApp = new RestApplication();
     restApp.sequence(MySequence);
 
-    const appServer = await restApp.getServer(RestServer);
-    await whenIRequest(appServer)
+    await whenIRequest(restApp)
       .get('/name')
       .expect('MySequence was invoked.');
   });
@@ -213,7 +213,7 @@ describe('Sequence', () => {
     app.controller(controller);
   }
 
-  function whenIRequest(restServer: RestServer = server): Client {
-    return createClientForHandler(restServer.handleHttp);
+  function whenIRequest(restServerOrApp: HttpServerLike = server): Client {
+    return createClientForHandler(restServerOrApp.requestHandler);
   }
 });