Merge pull request #1268 from opencomponents/improve-events-handler-types

[IMPROVEMENT] Improve typings of events in events handler

Author: ricardo-devis-agullo

src/cli/facade/dev.ts

@@ -124,19 +124,16 @@ const dev =
       const mockedPlugins = getMockedPlugins(logger, componentsDir);
       mockedPlugins.forEach(p => registry.register(p));
 
-      registry.on(
-        'request',
-        (data: { errorCode: string; errorDetails: string }) => {
-          if (data.errorCode === 'PLUGIN_MISSING_FROM_REGISTRY') {
-            logger.err(
-              cliErrors.PLUGIN_MISSING_FROM_REGISTRY(
-                data.errorDetails,
-                colors.blue(strings.commands.cli.MOCK_PLUGIN)
-              )
-            );
-          }
+      registry.on('request', data => {
+        if (data.errorCode === 'PLUGIN_MISSING_FROM_REGISTRY') {
+          logger.err(
+            cliErrors.PLUGIN_MISSING_FROM_REGISTRY(
+              data.errorDetails!,
+              colors.blue(strings.commands.cli.MOCK_PLUGIN)
+            )
+          );
         }
-      );
+      });
     };
 
     logger.warn(cliMessages.SCANNING_COMPONENTS, true);

src/registry/domain/components-cache/index.ts

@@ -1,6 +1,6 @@
 import _ from 'lodash';
 import getComponentsList from './components-list';
-import * as eventsHandler from '../events-handler';
+import eventsHandler from '../events-handler';
 import getUnixUTCTimestamp from 'oc-get-unix-utc-timestamp';
 import { Cdn, ComponentsList, Config } from '../../../types';
 

src/registry/domain/components-details.ts

@@ -1,6 +1,6 @@
 import async from 'async';
 import _ from 'lodash';
-import * as eventsHandler from './events-handler';
+import eventsHandler from './events-handler';
 import getUnixUTCTimestamp from 'oc-get-unix-utc-timestamp';
 import {
   Cdn,
@@ -16,7 +16,10 @@ export default function componentsDetails(conf: Config, cdn: Cdn) {
     message: string | Error,
     callback: (code: string) => void
   ) => {
-    eventsHandler.fire('error', { code, message });
+    eventsHandler.fire('error', {
+      code,
+      message: (message as Error)?.message ?? message
+    });
     return callback(code);
   };
 

src/registry/domain/events-handler.ts

@@ -1,40 +1,86 @@
+import { IncomingHttpHeaders } from 'http';
 import strings from '../../resources';
 
 type Subscription<T = any> = (data: T) => void;
 let subscriptions: Record<string, Array<Subscription>> = {};
 
-export function fire(eventName: string, eventData: unknown): void {
-  if (subscriptions[eventName]) {
-    subscriptions[eventName].forEach(callback => {
-      callback(eventData);
-    });
-  }
+export interface RequestData {
+  body: any;
+  duration: number;
+  headers: IncomingHttpHeaders;
+  method: string;
+  path: string;
+  relativeUrl: string;
+  query: Record<string, any>;
+  url: string;
+  statusCode: number;
+  errorDetails?: string;
+  errorCode?: string;
 }
 
-export function on(eventName: string, callback: Subscription): void {
-  if (typeof callback !== 'function') {
-    throw strings.errors.registry.CONFIGURATION_ONREQUEST_MUST_BE_FUNCTION;
-  }
+type Events = {
+  error: { code: string; message: string };
+  start: unknown;
+  'cache-poll': number;
+  request: RequestData;
+  'component-retrieved': {
+    headers: IncomingHttpHeaders;
+    name: string;
+    parameters: IncomingHttpHeaders;
+    requestVersion: string;
+    duration: number;
+  };
+};
 
-  if (!subscriptions[eventName]) {
-    subscriptions[eventName] = [];
-  }
+type EventsHandler = {
+  fire<T extends keyof Events>(eventName: T, data: Events[T]): void;
+  on<T extends keyof Events>(
+    eventName: T,
+    listener: Subscription<Events[T]>
+  ): void;
+  off<T extends keyof Events>(
+    eventName: T,
+    listener: Subscription<Events[T]>
+  ): void;
+  reset(): void;
+};
 
-  subscriptions[eventName].push(callback);
-}
+const eventsHandler: EventsHandler = {
+  fire(eventName: string, eventData: unknown): void {
+    if (subscriptions[eventName]) {
+      subscriptions[eventName].forEach(callback => {
+        callback(eventData);
+      });
+    }
+  },
 
-export function off(eventName: string, callback: Subscription): void {
-  if (typeof callback !== 'function') {
-    throw strings.errors.registry.CONFIGURATION_OFFREQUEST_MUST_BE_FUNCTION;
-  }
+  on(eventName: string, callback: Subscription): void {
+    if (typeof callback !== 'function') {
+      throw strings.errors.registry.CONFIGURATION_ONREQUEST_MUST_BE_FUNCTION;
+    }
+
+    if (!subscriptions[eventName]) {
+      subscriptions[eventName] = [];
+    }
 
-  if (subscriptions[eventName]) {
-    subscriptions[eventName] = subscriptions[eventName].filter(
-      sub => sub !== callback
-    );
+    subscriptions[eventName].push(callback);
+  },
+
+  off(eventName: string, callback: Subscription): void {
+    if (typeof callback !== 'function') {
+      throw strings.errors.registry.CONFIGURATION_OFFREQUEST_MUST_BE_FUNCTION;
+    }
+
+    if (subscriptions[eventName]) {
+      subscriptions[eventName] = subscriptions[eventName].filter(
+        sub => sub !== callback
+      );
+    }
+  },
+
+  reset(): void {
+    subscriptions = {};
   }
-}
+};
 
-export function reset(): void {
-  subscriptions = {};
-}
+export default eventsHandler;

src/registry/index.ts

@@ -5,7 +5,7 @@ import http from 'http';
 import _ from 'lodash';
 
 import appStart from './app-start';
-import * as eventsHandler from './domain/events-handler';
+import eventsHandler from './domain/events-handler';
 import * as middleware from './middleware';
 import * as pluginsInitialiser from './domain/plugins-initialiser';
 import Repository from './domain/repository';
@@ -117,9 +117,12 @@ export default function registry(inputOptions: Input) {
           callback(null, { app, server });
         });
 
-        server.on('error', message => {
-          eventsHandler.fire('error', { code: 'EXPRESS_ERROR', message });
-          callback(message, undefined as any);
+        server.on('error', error => {
+          eventsHandler.fire('error', {
+            code: 'EXPRESS_ERROR',
+            message: error?.message ?? String(error)
+          });
+          callback(error, undefined as any);
         });
       }
     );

src/registry/middleware/request-handler.ts

@@ -1,26 +1,11 @@
 import { Request, RequestHandler, Response } from 'express';
-import { IncomingHttpHeaders } from 'http';
 import responseTime from 'response-time';
 
-import * as eventsHandler from '../domain/events-handler';
-
-interface ResponseTimeData {
-  body: any;
-  duration: number;
-  headers: IncomingHttpHeaders;
-  method: string;
-  path: string;
-  relativeUrl: string;
-  query: Record<string, any>;
-  url: string;
-  statusCode: number;
-  errorDetails?: string;
-  errorCode?: string;
-}
+import eventsHandler, { RequestData } from '../domain/events-handler';
 
 export default function requestHandler(): RequestHandler {
   return responseTime((req: Request, res: Response, time) => {
-    const data: ResponseTimeData = {
+    const data: RequestData = {
       body: req.body,
       duration: parseInt(String(time * 1000)),
       headers: req.headers,
@@ -32,12 +17,12 @@ export default function requestHandler(): RequestHandler {
       statusCode: res.statusCode
     };
 
-    if ((res as any).errorDetails) {
-      data.errorDetails = (res as any).errorDetails;
+    if (res.errorDetails) {
+      data.errorDetails = res.errorDetails;
     }
 
-    if ((res as any).errorCode) {
-      data.errorCode = (res as any).errorCode;
+    if (res.errorCode) {
+      data.errorCode = res.errorCode;
     }
 
     eventsHandler.fire('request', data);

src/registry/routes/helpers/get-component.ts

@@ -7,7 +7,7 @@ import vm from 'vm';
 import _ from 'lodash';
 
 import applyDefaultValues from './apply-default-values';
-import * as eventsHandler from '../../domain/events-handler';
+import eventsHandler from '../../domain/events-handler';
 import GetComponentRetrievingInfo from './get-component-retrieving-info';
 import * as getComponentFallback from './get-component-fallback';
 import isTemplateLegacy from '../../../utils/is-template-legacy';

test/unit/registry-domain-events-handler.js

@@ -4,15 +4,16 @@ const expect = require('chai').expect;
 const sinon = require('sinon');
 
 describe('registry : domain : events-handler', () => {
-  const eventsHandler = require('../../dist/registry/domain/events-handler');
+  const eventsHandler =
+    require('../../dist/registry/domain/events-handler').default;
 
   describe('when requiring it multiple times', () => {
     const spy = sinon.spy();
     let handler2;
 
     before(() => {
       eventsHandler.on('eventName', spy);
-      handler2 = require('../../dist/registry/domain/events-handler');
+      handler2 = require('../../dist/registry/domain/events-handler').default;
       handler2.fire('eventName', { a: 1234 });
     });