feat(rest): use @loopback/express-middleware to manage express middle…

…ware

packages/rest/package.json

@@ -23,6 +23,7 @@
     "@loopback/context": "^1.6.0",
     "@loopback/core": "^1.1.7",
     "@loopback/http-server": "^1.1.7",
+    "@loopback/express-middleware": "^1.0.0-1",
     "@loopback/openapi-v3": "^1.2.3",
     "@loopback/openapi-v3-types": "^1.0.7",
     "@types/body-parser": "^1.17.0",

packages/rest/src/keys.ts

@@ -3,37 +3,35 @@
 // This file is licensed under the MIT License.
 // License text available at https://opensource.org/licenses/MIT
 
-import {CoreBindings} from '@loopback/core';
 import {BindingKey, Context} from '@loopback/context';
-
+import {CoreBindings} from '@loopback/core';
+import {ExpressContext} from '@loopback/express-middleware';
+import {HttpProtocol} from '@loopback/http-server';
+import * as https from 'https';
 /**
  * See https://github.com/Microsoft/TypeScript/issues/26985
  */
 // import {OpenApiSpec} from '@loopback/openapi-v3-types';
 import {OpenAPIObject as OpenApiSpec} from 'openapi3-ts';
-
+import {ErrorWriterOptions} from 'strong-error-handler';
+import {BodyParser, RequestBodyParser} from './body-parsers';
 import {HttpHandler} from './http-handler';
+import {RestRouter} from './router';
 import {SequenceHandler} from './sequence';
 import {
   BindElement,
   FindRoute,
   GetFromContext,
   InvokeMethod,
   LogError,
-  Request,
-  Response,
   ParseParams,
   Reject,
-  Send,
+  Request,
   RequestBodyParserOptions,
+  Response,
+  Send,
 } from './types';
 
-import {HttpProtocol} from '@loopback/http-server';
-import * as https from 'https';
-import {ErrorWriterOptions} from 'strong-error-handler';
-import {RestRouter} from './router';
-import {RequestBodyParser, BodyParser} from './body-parsers';
-
 /**
  * RestServer-specific bindings
  */
@@ -80,6 +78,13 @@ export namespace RestBindings {
    */
   export const ROUTER = BindingKey.create<RestRouter>('rest.router');
 
+  /**
+   * Binding key for rest express context
+   */
+  export const EXPRESS_CONTEXT = BindingKey.create<ExpressContext>(
+    'rest.express.context',
+  );
+
   /**
    * Binding key for setting and injecting Reject action's error handling
    * options.

packages/rest/src/rest.server.ts

@@ -5,13 +5,14 @@
 
 import {
   Binding,
+  BindingAddress,
+  BindingScope,
   Constructor,
   Context,
   inject,
-  BindingScope,
-  BindingAddress,
 } from '@loopback/context';
 import {Application, CoreBindings, Server} from '@loopback/core';
+import {ExpressContext} from '@loopback/express-middleware';
 import {HttpServer, HttpServerOptions} from '@loopback/http-server';
 import {getControllerSpec} from '@loopback/openapi-v3';
 import {
@@ -38,11 +39,11 @@ import {
   ControllerInstance,
   ControllerRoute,
   createControllerFactoryForBinding,
+  ExternalExpressRoutes,
+  RedirectRoute,
   Route,
   RouteEntry,
   RoutingTable,
-  ExternalExpressRoutes,
-  RedirectRoute,
 } from './router';
 import {DefaultSequence, SequenceFunction, SequenceHandler} from './sequence';
 import {
@@ -51,9 +52,9 @@ import {
   ParseParams,
   Reject,
   Request,
+  RequestBodyParserOptions,
   Response,
   Send,
-  RequestBodyParserOptions,
 } from './types';
 
 const debug = debugFactory('loopback:rest:server');
@@ -218,6 +219,12 @@ export class RestServer extends Context implements Server, HttpServerLike {
     this._applyExpressSettings();
     this._requestHandler = this._expressApp;
 
+    const expressCtx = new ExpressContext(this);
+    expressCtx.setMiddlewareRegistryOptions({
+      phasesByOrder: ['cors', 'openapi-spec', 'rest'],
+    });
+    this.bind(RestBindings.EXPRESS_CONTEXT).to(expressCtx);
+
     // Allow CORS support for all endpoints so that users
     // can test with online SwaggerUI instance
     const corsOptions = this.config.cors || {
@@ -228,22 +235,33 @@ export class RestServer extends Context implements Server, HttpServerLike {
       maxAge: 86400,
       credentials: true,
     };
-    this._expressApp.use(cors(corsOptions));
+
+    expressCtx.middleware(cors(corsOptions), {phase: 'cors', name: 'cors'});
 
     // Set up endpoints for OpenAPI spec/ui
-    this._setupOpenApiSpecEndpoints();
+    this._setupOpenApiSpecEndpoints(expressCtx);
 
     // Mount our router & request handler
-    this._expressApp.use(this._basePath, (req, res, next) => {
-      this._handleHttpRequest(req, res).catch(next);
-    });
+    expressCtx.middleware(
+      (req, res, next) => {
+        this._handleHttpRequest(req, res).catch(next);
+      },
+      {
+        path: this._basePath,
+        phase: 'rest',
+        name: 'rest',
+      },
+    );
 
     // Mount our error handler
-    this._expressApp.use(
+    expressCtx.errorMiddleware(
       (err: Error, req: Request, res: Response, next: Function) => {
         this._onUnhandledError(req, res, err);
       },
+      {name: 'error'},
     );
+
+    this._expressApp.use(expressCtx.requestHandler);
   }
 
   /**
@@ -260,7 +278,7 @@ export class RestServer extends Context implements Server, HttpServerLike {
    * Mount /openapi.json, /openapi.yaml for specs and /swagger-ui, /explorer
    * to redirect to externally hosted API explorer
    */
-  protected _setupOpenApiSpecEndpoints() {
+  protected _setupOpenApiSpecEndpoints(expressCtx: ExpressContext) {
     if (this.config.openApiSpec!.disabled) return;
     // NOTE(bajtos) Regular routes are handled through Sequence.
     // IMO, this built-in endpoint should not run through a Sequence,
@@ -272,14 +290,24 @@ export class RestServer extends Context implements Server, HttpServerLike {
     const mapping = this.config.openApiSpec!.endpointMapping!;
     // Serving OpenAPI spec
     for (const p in mapping) {
-      this._expressApp.get(p, (req, res) =>
-        this._serveOpenApiSpec(req, res, mapping[p]),
+      expressCtx.middleware(
+        (req, res) => this._serveOpenApiSpec(req, res, mapping[p]),
+        {
+          path: p,
+          method: 'get',
+          phase: 'openapi-spec',
+        },
       );
     }
 
     const explorerPaths = ['/swagger-ui', '/explorer'];
-    this._expressApp.get(explorerPaths, (req, res, next) =>
-      this._redirectToSwaggerUI(req, res, next),
+    expressCtx.middleware(
+      (req, res, next) => this._redirectToSwaggerUI(req, res, next),
+      {
+        path: explorerPaths,
+        method: 'get',
+        phase: 'openapi-spec',
+      },
     );
   }