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

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

@@ -13,6 +13,7 @@ import {
   Constructor,
   instantiateClass,
   invokeMethod,
+  BindingScope,
 } from '@loopback/context';
 import {ServerRequest} from 'http';
 import * as HttpErrors from 'http-errors';
@@ -261,6 +262,7 @@ export class Route extends BaseRoute {
 type ControllerInstance = {[opName: string]: Function};
 
 export class ControllerRoute extends BaseRoute {
+  protected readonly _controllerBindingKey: string;
   protected readonly _methodName: string;
 
   constructor(
@@ -298,6 +300,7 @@ export class ControllerRoute extends BaseRoute {
     }
 
     this._methodName = methodName;
+    this._controllerBindingKey = `controllers.${this._controllerCtor.name}`;
   }
 
   describe(): string {
@@ -306,6 +309,12 @@ export class ControllerRoute extends BaseRoute {
 
   updateBindings(requestContext: Context) {
     const ctor = this._controllerCtor;
+    if (!requestContext.contains(this._controllerBindingKey)) {
+      requestContext
+        .bind(this._controllerBindingKey)
+        .toClass(ctor)
+        .inScope(BindingScope.SINGLETON);
+    }
     requestContext.bind('controller.current.ctor').to(ctor);
     requestContext.bind('controller.current.operation').to(this._methodName);
   }
@@ -329,14 +338,10 @@ 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;
+    return requestContext.get(this._controllerBindingKey);
   }
 }
 

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

@@ -314,6 +314,32 @@ 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);