feat: add after-action middleware hook to controller (#459)

* feat: add after-action middleware hook to controller

* test: add unit tests for #execHandlers() in route class

* test: ensure terminating before action functions are covered

* test: add unit test for route constructor and fix before action only tests

src/packages/application/utils/create-controller.js

@@ -59,6 +59,11 @@ export default function createController<T: Controller>(
       ...parent.beforeAction.map(fn => fn.bind(parent)),
       ...instance.beforeAction.map(fn => fn.bind(instance))
     ];
+
+    instance.afterAction = [
+      ...instance.afterAction.map(fn => fn.bind(instance)),
+      ...parent.afterAction.map(fn => fn.bind(parent))
+    ];
   }
 
   Reflect.defineProperty(instance, 'parent', {
@@ -73,6 +78,7 @@ export default function createController<T: Controller>(
     'sort',
     'filter',
     'params',
-    'beforeAction'
+    'beforeAction',
+    'afterAction'
   );
 }

src/packages/controller/index.js

@@ -9,7 +9,11 @@ import type { Request, Response } from '../server'; // eslint-disable-line max-l
 import findOne from './utils/find-one';
 import findMany from './utils/find-many';
 import findRelated from './utils/find-related';
-import type { Controller$opts, Controller$Middleware } from './interfaces';
+import type {
+  Controller$opts,
+  Controller$beforeAction,
+  Controller$afterAction
+} from './interfaces';
 
 /**
  * The `Controller` class is responsible for taking in requests from the outside
@@ -124,7 +128,19 @@ class Controller {
    * @memberof Controller
    * @instance
    */
-  beforeAction: Array<Controller$Middleware> = [];
+  beforeAction: Array<Controller$beforeAction> = [];
+
+  /**
+   * Middleware functions to execute on each request handled by a `Controller`.
+   *
+   * Middleware functions declared in afterAction on an `ApplicationController`
+   * will be executed after ALL route handlers.
+   *
+   * @property afterAction
+   * @memberof Controller
+   * @instance
+   */
+  afterAction: Array<Controller$afterAction> = [];
 
   /**
    * The number of records to return for the #index action when a `?limit`
@@ -349,5 +365,6 @@ export { BUILT_IN_ACTIONS } from './constants';
 export type {
   Controller$opts,
   Controller$builtIn,
-  Controller$Middleware,
+  Controller$beforeAction,
+  Controller$afterAction,
 } from './interfaces';

src/packages/controller/interfaces.js

@@ -5,9 +5,9 @@ import type Serializer from '../serializer';
 import type Controller from './index';
 
 export type Controller$opts = {
-  model: Class<Model>;
-  namespace: string;
-  serializer: Serializer<*>;
+  model?: Class<Model>;
+  namespace?: string;
+  serializer?: Serializer<*>;
 };
 
 export type Controller$builtIn =
@@ -17,11 +17,17 @@ export type Controller$builtIn =
   | 'update'
   | 'destroy';
 
-export type Controller$Middleware = (
+export type Controller$beforeAction = (
   request: Request,
   response: Response
 ) => Promise<any>;
 
+export type Controller$afterAction = (
+  request: Request,
+  response: Response,
+  responseData: any
+) => Promise<any>;
+
 export type Controller$findOne<T: Model> = (
   request: Request
 ) => Query<T>;

src/packages/router/route/action/enhancers/resource.js

@@ -8,7 +8,8 @@ import type { Action } from '../interfaces';
 * @private
 */
 export default function resource(action: Action<any>): Action<any> {
-  return async function resourceAction(req, res) {
+  // eslint-disable-next-line func-names
+  const resourceAction = async function (req, res) {
     const { route: { action: actionName } } = req;
     const result = action(req, res);
     let links = {};
@@ -72,4 +73,10 @@ export default function resource(action: Action<any>): Action<any> {
 
     return data;
   };
+
+  Reflect.defineProperty(resourceAction, 'name', {
+    value: action.name
+  });
+
+  return resourceAction;
 }

src/packages/router/route/action/enhancers/track-perf.js

@@ -8,9 +8,11 @@ import type { Action } from '../interfaces';
  * @private
  */
 export default function trackPerf<T, U: Action<T>>(action: U): Action<T> {
-  return async function trackedAction(req, res) {
+  // eslint-disable-next-line func-names
+  const trackedAction = async function (...args: Array<any>) {
+    const [req, res] = args;
     const start = Date.now();
-    const result = await action(req, res);
+    const result = await action(...args);
     let { name } = action;
     let type = 'middleware';
 
@@ -30,4 +32,10 @@ export default function trackPerf<T, U: Action<T>>(action: U): Action<T> {
 
     return result;
   };
+
+  Reflect.defineProperty(trackedAction, 'name', {
+    value: action.name
+  });
+
+  return trackedAction;
 }

src/packages/router/route/action/index.js

@@ -24,10 +24,12 @@ export function createAction(
     // eslint-disable-next-line no-underscore-dangle
     function __FINAL_HANDLER__(req, res) {
       return fn(req, res);
-    }
+    },
+    ...controller.afterAction,
   ].map(trackPerf);
 }
 
+export { FINAL_HANDLER } from './constants';
 export { default as createPageLinks } from './utils/create-page-links';
 
 export type { Action } from './interfaces';

src/packages/router/route/action/test/track-perf.test.js

@@ -4,13 +4,10 @@ import { it, describe, before } from 'mocha';
 
 import type { Action } from '../../../index';
 import type { Request, Response } from '../../../../server';
+import sleep from '../../../../../utils/sleep';
 import trackPerf from '../enhancers/track-perf';
 import { getTestApp } from '../../../../../../test/utils/get-test-app';
 
-function sleep(amount: number) {
-  return new Promise(resolve => setTimeout(resolve, amount));
-}
-
 describe('module "router/route/action"', () => {
   describe('enhancer trackPerf()', () => {
     let createRequest;

src/packages/router/route/index.js

@@ -3,7 +3,7 @@ import { FreezeableSet, freezeProps, deepFreezeProps } from '../../freezeable';
 import type Controller from '../../controller';
 import type { Request, Response, Request$method } from '../../server';
 
-import { createAction } from './action';
+import { FINAL_HANDLER, createAction } from './action';
 import { paramsFor, defaultParamsFor, validateResourceId } from './params';
 import getStaticPath from './utils/get-static-path';
 import getDynamicSegments from './utils/get-dynamic-segments';
@@ -127,15 +127,22 @@ class Route extends FreezeableSet<Action<any>> {
   }
 
   async execHandlers(req: Request, res: Response): Promise<any> {
+    let calledFinal = false;
+    let data;
+
     for (const handler of this) {
-      const data = await handler(req, res);
+      data = await handler(req, res, data);
+
+      if (handler.name === FINAL_HANDLER) {
+        calledFinal = true;
+      }
 
-      if (typeof data !== 'undefined') {
-        return data;
+      if (!calledFinal && typeof data !== 'undefined') {
+        break;
       }
     }
 
-    return undefined;
+    return data;
   }
 
   async visit(req: Request, res: Response): Promise<any> {