Add a useResponseClassTransformer global option

Author: Aleksi Pekkala

README.md

@@ -509,6 +509,10 @@ If you specify a class type to parameter that is decorated with parameter decora
 routing-controllers will use [class-transformer][4] to create instance of that class type.
 More info about this feature is available [here](#creating-instances-of-classes-from-action-params).
 
+#### Disable response transformation
+
+By default response values are coerced to plain objects with [class-transformer](https://github.com/pleerock/class-transformer). When returning large objects or values with complex serialization logic (e.g. Mongoose documents) you might opt for the default `toJSON` handler instead. To disable response transformation simply pass `useResponseClassTransformer: false` to createExpressServer method.
+
 #### Set custom ContentType
 
 You can specify a custom ContentType header:
@@ -694,7 +698,7 @@ There are set of prepared errors you can use:
 * UnauthorizedError
 
 
-You can also create and use your own errors by extending `HttpError` class.  
+You can also create and use your own errors by extending `HttpError` class.
 To define the data returned to the client, you could define a toJSON method in your error.
 
 ```typescript
@@ -716,7 +720,7 @@ class DbError extends HttpError {
         }
     }
 }
-``` 
+```
 
 #### Enable CORS
 
@@ -757,7 +761,7 @@ app.listen(3000);
 
 #### Default settings
 
-You can override default status code in routing-controllers options. 
+You can override default status code in routing-controllers options.
 
 ```typescript
 import "reflect-metadata";
@@ -770,9 +774,9 @@ const app = createExpressServer({
         //with this option, null will return 404 by default
         nullResultCode: 404,
 
-        //with this option, void or Promise<void> will return 204 by default 
+        //with this option, void or Promise<void> will return 204 by default
         undefinedResultCode: 204,
-        
+
         paramOptions: {
             //with this option, argument will be required by default
             required: true

src/RoutingControllersOptions.ts

@@ -40,6 +40,12 @@ export interface RoutingControllersOptions {
      */
     classTransformer?: boolean;
 
+    /**
+     * Toggles class-transformer serialization for response values.
+     * Overwritten by a negative classTransformer value.
+     */
+    useResponseClassTransformer?: boolean;
+
     /**
      * Global class transformer options passed to class-transformer during classToPlain operation.
      * This operation is being executed when server returns response to user.
@@ -85,7 +91,7 @@ export interface RoutingControllersOptions {
      * Special function used to get currently authorized user.
      */
     currentUserChecker?: CurrentUserChecker;
-    
+
     /**
      * Default settings
      */
@@ -110,4 +116,4 @@ export interface RoutingControllersOptions {
             required?: boolean;
         };
     };
-}
+}

src/driver/BaseDriver.ts

@@ -29,6 +29,12 @@ export abstract class BaseDriver {
      */
     useClassTransformer: boolean;
 
+    /**
+     * Toggles class-transformer serialization for response values.
+     * Overwritten by a negative classTransformer value.
+     */
+    useResponseClassTransformer: boolean;
+
     /**
      * Indicates if class-validator should be used or not.
      */
@@ -44,7 +50,7 @@ export abstract class BaseDriver {
      * Global class-validator options passed during validate operation.
      */
     validationOptions: ValidatorOptions;
-    
+
     /**
      * Global class transformer options passed to class-transformer during plainToClass operation.
      * This operation is being executed when parsing user parameters.
@@ -92,7 +98,7 @@ export abstract class BaseDriver {
      * Initializes the things driver needs before routes and middleware registration.
      */
     abstract initialize(): void;
-    
+
     /**
      * Registers given middleware.
      */
@@ -129,14 +135,14 @@ export abstract class BaseDriver {
 
     protected transformResult(result: any, action: ActionMetadata, options: Action): any {
         // check if we need to transform result
-        const shouldTransform = (this.useClassTransformer && result != null) // transform only if enabled and value exist
+        const shouldTransform = (this.useClassTransformer && this.useResponseClassTransformer && result != null) // transform only if enabled and value exist
             && result instanceof Object // don't transform primitive types (string/number/boolean)
             && !(
                 result instanceof Uint8Array // don't transform binary data
                 ||
                 result.pipe instanceof Function // don't transform streams
             );
-            
+
         // transform result if needed
         if (shouldTransform) {
             const options = action.responseClassTransformOptions || this.classToPlainTransformOptions;
@@ -152,7 +158,7 @@ export abstract class BaseDriver {
 
         if (typeof error.toJSON === "function")
             return error.toJSON();
-        
+
         let processedError: any = {};
         if (error instanceof Error) {
             const name = error.name && error.name !== "Error" ? error.name : error.constructor.name;

src/index.ts

@@ -190,6 +190,12 @@ export function createExecutor<T extends BaseDriver>(driver: T, options: Routing
         driver.useClassTransformer = true;
     }
 
+    if (options.useResponseClassTransformer !== undefined) {
+        driver.useResponseClassTransformer = options.useResponseClassTransformer;
+    } else {
+        driver.useResponseClassTransformer = true;
+    }
+
     if (options.validation !== undefined) {
         driver.enableValidation = !!options.validation;
         if (options.validation instanceof Object)

test/functional/global-options.spec.ts

@@ -10,8 +10,14 @@ const expect = chakram.expect;
 export class User {
     firstName: string;
     lastName: string;
-    getName(): string {
-        return this.firstName + " " + this.lastName;
+    password: string;
+
+    /**
+     * This method only gets called when class-transformer serialization for
+     * response values is disabled.
+     */
+    toJSON() {
+        return {firstName: this.firstName, lastName: this.lastName};
     }
 }
 
@@ -34,43 +40,49 @@ describe("routing-controllers global options", () => {
             @Post("/users")
             postUsers(@Body() user: User) {
                 initializedUser = user;
-                return "";
+                const ret = new User();
+                ret.firstName = user.firstName;
+                ret.lastName = user.lastName;
+                ret.password = "1234";
+                return ret;
             }
-            
+
             @Post(new RegExp("/(prefix|regex)/users"))
             postUsersWithRegex(@Body() user: User) {
                 initializedUser = user;
                 return "";
             }
-            
+
         }
     });
 
-    describe("useClassTransformer by default must be set to true", () => {
+    describe("useClassTransformer and useResponseClassTransformer by default must be set to true", () => {
 
         let expressApp: any, koaApp: any;
         before(done => expressApp = createExpressServer().listen(3001, done));
         after(done => expressApp.close(done));
         before(done => koaApp = createKoaServer().listen(3002, done));
         after(done => koaApp.close(done));
 
-        assertRequest([3001, 3002], "post", "users", { firstName: "Umed", lastName: "Khudoiberdiev" }, response => {
+        assertRequest([3001, 3002], "post", "users", { firstName: "Umed", lastName: "Khudoiberdiev", password: "1234" }, response => {
             expect(initializedUser).to.be.instanceOf(User);
             expect(response).to.have.status(200);
+            expect(response.body.password).to.be.defined;
         });
     });
 
-    describe("when useClassTransformer is set to true", () => {
+    describe("when useClassTransformer and useResponseClassTransformer are set to true", () => {
 
         let expressApp: any, koaApp: any;
-        before(done => expressApp = createExpressServer({ classTransformer: true }).listen(3001, done));
+        before(done => expressApp = createExpressServer({ classTransformer: true, useResponseClassTransformer: true }).listen(3001, done));
         after(done => expressApp.close(done));
-        before(done => koaApp = createKoaServer({ classTransformer: true }).listen(3002, done));
+        before(done => koaApp = createKoaServer({ classTransformer: true, useResponseClassTransformer: true }).listen(3002, done));
         after(done => koaApp.close(done));
 
-        assertRequest([3001, 3002], "post", "users", { firstName: "Umed", lastName: "Khudoiberdiev" }, response => {
+        assertRequest([3001, 3002], "post", "users", { firstName: "Umed", lastName: "Khudoiberdiev", password: "1234" }, response => {
             expect(initializedUser).to.be.instanceOf(User);
             expect(response).to.have.status(200);
+            expect(response.body.password).to.be.defined;
         });
     });
 
@@ -81,22 +93,38 @@ describe("routing-controllers global options", () => {
         after(done => expressApp.close(done));
         before(done => koaApp = createKoaServer({ classTransformer: false }).listen(3002, done));
         after(done => koaApp.close(done));
-    
-        assertRequest([3001, 3002], "post", "users", { firstName: "Umed", lastName: "Khudoiberdiev" }, response => {
+
+        assertRequest([3001, 3002], "post", "users", { firstName: "Umed", lastName: "Khudoiberdiev", password: "1234" }, response => {
             expect(initializedUser).not.to.be.instanceOf(User);
             expect(response).to.have.status(200);
+            expect(response.body.password).to.be.undefined;
+        });
+    });
+
+    describe("when useClassTransformer is set but useResponseClassTransformer is not", () => {
+
+        let expressApp: any, koaApp: any;
+        before(done => expressApp = createExpressServer({ useResponseClassTransformer: false }).listen(3001, done));
+        after(done => expressApp.close(done));
+        before(done => koaApp = createKoaServer({ useResponseClassTransformer: false }).listen(3002, done));
+        after(done => koaApp.close(done));
+
+        assertRequest([3001, 3002], "post", "users", { firstName: "Umed", lastName: "Khudoiberdiev", password: "1234" }, response => {
+            expect(initializedUser).to.be.instanceOf(User);
+            expect(response).to.have.status(200);
+            expect(response.body.password).to.be.undefined;
         });
     });
 
     describe("when routePrefix is used all controller routes should be appended by it", () => {
-    
+
         let apps: any[] = [];
         before(done => apps.push(createExpressServer({ routePrefix: "/api" }).listen(3001, done)));
         before(done => apps.push(createExpressServer({ routePrefix: "api" }).listen(3002, done)));
         before(done => apps.push(createKoaServer({ routePrefix: "/api" }).listen(3003, done)));
         before(done => apps.push(createKoaServer({ routePrefix: "api" }).listen(3004, done)));
         after(done => { apps.forEach(app => app.close()); done(); });
-    
+
         assertRequest([3001, 3002, 3003, 3004], "post", "api/users", { firstName: "Umed", lastName: "Khudoiberdiev" }, response => {
             expect(initializedUser).to.be.instanceOf(User);
             expect(response).to.have.status(200);
@@ -108,4 +136,4 @@ describe("routing-controllers global options", () => {
         });
     });
 
-});
+});