fix(rest): use context.get() to resolve current controller

packages/rest/src/http-handler.ts

@@ -3,7 +3,7 @@
 // This file is licensed under the MIT License.
 // License text available at https://opensource.org/licenses/MIT
 
-import {Context} from '@loopback/context';
+import {Context, Binding} from '@loopback/context';
 import {PathsObject, DefinitionsObject} from '@loopback/openapi-spec';
 import {ServerRequest, ServerResponse} from 'http';
 import {ControllerSpec} from '@loopback/openapi-v2';
@@ -33,8 +33,12 @@ export class HttpHandler {
     this.handleRequest = (req, res) => this._handleRequest(req, res);
   }
 
-  registerController(name: ControllerClass, spec: ControllerSpec) {
-    this._routes.registerController(name, spec);
+  registerController(
+    name: ControllerClass,
+    spec: ControllerSpec,
+    binding?: Binding,
+  ) {
+    this._routes.registerController(name, spec, binding);
   }
 
   registerRoute(route: RouteEntry) {

packages/rest/src/rest-server.ts

@@ -215,7 +215,7 @@ export class RestServer extends Context implements Server {
       if (apiSpec.definitions) {
         this._httpHandler.registerApiDefinitions(apiSpec.definitions);
       }
-      this._httpHandler.registerController(ctor, apiSpec);
+      this._httpHandler.registerController(ctor, apiSpec, b);
     }
 
     for (const b of this.find('routes.*')) {
@@ -264,7 +264,7 @@ export class RestServer extends Context implements Server {
         );
       }
 
-      const route = new ControllerRoute(verb, path, spec, ctor);
+      const route = new ControllerRoute(verb, path, spec, ctor, undefined, b);
       this._httpHandler.registerRoute(route);
       return;
     }

packages/rest/src/router/routing-table.ts

@@ -9,10 +9,11 @@ import {
   PathsObject,
 } from '@loopback/openapi-spec';
 import {
+  BindingScope,
   Context,
   Constructor,
-  instantiateClass,
   invokeMethod,
+  Binding,
 } from '@loopback/context';
 import {ServerRequest} from 'http';
 import * as HttpErrors from 'http-errors';
@@ -66,7 +67,11 @@ export type ControllerClass = Constructor<any>;
 export class RoutingTable {
   private readonly _routes: RouteEntry[] = [];
 
-  registerController(controller: ControllerClass, spec: ControllerSpec) {
+  registerController(
+    controller: ControllerClass,
+    spec: ControllerSpec,
+    binding?: Binding,
+  ) {
     assert(
       typeof spec === 'object' && !!spec,
       'API specification must be a non-null object',
@@ -82,7 +87,14 @@ export class RoutingTable {
       for (const verb in spec.paths[p]) {
         const opSpec: OperationObject = spec.paths[p][verb];
         const fullPath = RoutingTable.joinPath(basePath, p);
-        const route = new ControllerRoute(verb, fullPath, opSpec, controller);
+        const route = new ControllerRoute(
+          verb,
+          fullPath,
+          opSpec,
+          controller,
+          undefined,
+          binding,
+        );
         this.registerRoute(route);
       }
     }
@@ -269,6 +281,7 @@ export class ControllerRoute extends BaseRoute {
     spec: OperationObject,
     protected readonly _controllerCtor: ControllerClass,
     methodName?: string,
+    protected _binding?: Binding,
   ) {
     super(
       verb,
@@ -306,6 +319,13 @@ export class ControllerRoute extends BaseRoute {
 
   updateBindings(requestContext: Context) {
     const ctor = this._controllerCtor;
+    if (!this._binding) {
+      // A binding does not exist. Create one in the request context.
+      this._binding = requestContext
+        .bind(`controllers.${ctor.name}`)
+        .toClass(ctor)
+        .inScope(BindingScope.SINGLETON);
+    }
     requestContext.bind('controller.current.ctor').to(ctor);
     requestContext.bind('controller.current.operation').to(this._methodName);
   }
@@ -329,14 +349,13 @@ export class ControllerRoute extends BaseRoute {
     );
   }
 
-  private async _createControllerInstance(
+  private _createControllerInstance(
     requestContext: Context,
   ): Promise<ControllerInstance> {
-    const valueOrPromise = instantiateClass(
-      this._controllerCtor,
-      requestContext,
-    );
-    return (await Promise.resolve(valueOrPromise)) as ControllerInstance;
+    const controllerBindingKey = this._binding
+      ? this._binding.key
+      : `controllers.${this._controllerCtor.name}`;
+    return requestContext.get(controllerBindingKey);
   }
 }
 

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

@@ -25,7 +25,7 @@ import {
 
 import {expect, Client, createClientForHandler} from '@loopback/testlab';
 import {anOpenApiSpec, anOperationSpec} from '@loopback/openapi-spec-builder';
-import {inject, Context} from '@loopback/context';
+import {inject, Context, BindingScope} from '@loopback/context';
 import {ControllerClass} from '../../../src/router/routing-table';
 
 /* # Feature: Routing
@@ -315,6 +315,32 @@ describe('Routing', () => {
       });
   });
 
+  it('binds the current controller', async () => {
+    const app = givenAnApplication();
+    const server = await givenAServer(app);
+    const spec = anOpenApiSpec()
+      .withOperationReturningString('get', '/name', 'checkController')
+      .build();
+
+    @api(spec)
+    class GetCurrentController {
+      async checkController(
+        @inject('controllers.GetCurrentController') inst: GetCurrentController,
+      ): Promise<object> {
+        return {
+          result: this === inst,
+        };
+      }
+    }
+    givenControllerInApp(app, GetCurrentController);
+
+    return whenIMakeRequestTo(server)
+      .get('/name')
+      .expect({
+        result: true,
+      });
+  });
+
   it('supports function-based routes', async () => {
     const app = givenAnApplication();
     const server = await givenAServer(app);
@@ -577,7 +603,7 @@ describe('Routing', () => {
   }
 
   function givenControllerInApp(app: Application, controller: ControllerClass) {
-    app.controller(controller);
+    app.controller(controller).inScope(BindingScope.CONTEXT);
   }
 
   function whenIMakeRequestTo(server: RestServer): Client {

packages/rest/test/unit/router/routing-table.test.ts

@@ -12,6 +12,7 @@ import {
 import {getControllerSpec, param, get} from '@loopback/openapi-v2';
 import {expect, ShotRequestOptions, ShotRequest} from '@loopback/testlab';
 import {anOpenApiSpec} from '@loopback/openapi-spec-builder';
+import {Binding} from '@loopback/context';
 
 describe('RoutingTable', () => {
   it('joins basePath and path', () => {
@@ -59,7 +60,7 @@ describe('RoutingTable', () => {
     class TestController {}
 
     const table = new RoutingTable();
-    table.registerController(TestController, spec);
+    table.registerController(TestController, spec, new Binding('foo'));
 
     const request = givenRequest({
       method: 'get',