fix: Improve transport-commons types (#1396)

packages/transport-commons/src/channels/index.ts

@@ -1,20 +1,20 @@
 import Debug from 'debug';
-import { get, compact, flattenDeep, noop } from 'lodash';
+import { compact, flattenDeep, noop } from 'lodash';
 import { Channel } from './channel/base';
 import { CombinedChannel } from './channel/combined';
-import { channelMixin, publishMixin, keys } from './mixins';
+import { channelMixin, publishMixin, keys, PublishMixin, Event, Publisher } from './mixins';
 import { Application, Service } from '@feathersjs/feathers';
 
 const debug = Debug('@feathersjs/transport-commons/channels');
-const { CHANNELS, PUBLISHERS, ALL_EVENTS } = keys;
+const { CHANNELS } = keys;
 
 declare module '@feathersjs/feathers' {
   interface ServiceAddons<T> {
-    publish (callback: (data: T, hook: HookContext<T>) => Channel): this;
-    publish (event: string, callback: (data: T, hook: HookContext<T>) => Channel): this;
+    publish (publisher: Publisher<T>): this;
+    publish (event: Event, publisher: Publisher<T>): this;
 
-    registerPublisher (callback: (data: T, hook: HookContext<T>) => Channel): this;
-    registerPublisher (event: string, callback: (data: T, hook: HookContext<T>) => Channel): this;
+    registerPublisher (publisher: Publisher<T>): this;
+    registerPublisher (event: Event, publisher: Publisher<T>): this;
   }
 
   interface Application<ServiceTypes> {
@@ -23,11 +23,11 @@ declare module '@feathersjs/feathers' {
     channel (name: string[]): Channel;
     channel (...names: string[]): Channel;
 
-    publish<T> (callback: (data: T, hook: HookContext<T>) => Channel | Channel[] | void): Application<ServiceTypes>;
-    publish<T> (event: string, callback: (data: T, hook: HookContext<T>) => Channel | Channel[] | void): Application<ServiceTypes>;
+    publish<T> (publisher: Publisher<T>): this;
+    publish<T> (event: Event, publisher: Publisher<T>): this;
 
-    registerPublisher<T> (callback: (data: T, hook: HookContext<T>) => Channel | Channel[] | void): Application<ServiceTypes>;
-    registerPublisher<T> (event: string, callback: (data: T, hook: HookContext<T>) => Channel | Channel[] | void): Application<ServiceTypes>;
+    registerPublisher<T> (publisher: Publisher<T>): this;
+    registerPublisher<T> (event: Event, publisher: Publisher<T>): this;
   }
 }
 
@@ -63,22 +63,24 @@ export function channels () {
 
           debug('Publishing event', event, hook.path);
 
-          const servicePublishers = (service as any)[PUBLISHERS];
-          const appPublishers = (app as any)[PUBLISHERS];
+          const servicePublishers = (service as unknown as PublishMixin)[keys.PUBLISHERS];
+          const appPublishers = (app as unknown as PublishMixin)[keys.PUBLISHERS];
           // This will return the first publisher list that is not empty
           // In the following precedence
-          const callback = [
+          const publisher = (
             // 1. Service publisher for a specific event
-            get(servicePublishers, event),
+            servicePublishers[event] ||
             // 2. Service publisher for all events
-            get(servicePublishers, ALL_EVENTS),
-            // 3. App publishers for a specific event
-            get(appPublishers, event),
-            // 4. App publishers for all events
-            get(appPublishers, ALL_EVENTS)
-          ].find(current => typeof current === 'function') || noop;
-
-          Promise.resolve(callback(data, hook)).then(result => {
+            servicePublishers[keys.ALL_EVENTS] ||
+            // 3. App publisher for a specific event
+            appPublishers[event] ||
+            // 4. App publisher for all events
+            appPublishers[keys.ALL_EVENTS] ||
+            // 5. No publisher
+            noop
+          );
+
+          Promise.resolve(publisher(data, hook)).then(result => {
             if (!result) {
               return;
             }

packages/transport-commons/src/channels/mixins.ts

@@ -9,9 +9,9 @@ const CHANNELS = Symbol('@feathersjs/transport-commons/channels');
 const ALL_EVENTS = Symbol('@feathersjs/transport-commons/all-events');
 
 export const keys = {
-  PUBLISHERS,
-  CHANNELS,
-  ALL_EVENTS
+  PUBLISHERS: PUBLISHERS as typeof PUBLISHERS,
+  CHANNELS: CHANNELS as typeof CHANNELS,
+  ALL_EVENTS: ALL_EVENTS as typeof ALL_EVENTS,
 };
 
 export interface ChannelMixin {
@@ -60,10 +60,14 @@ export function channelMixin () {
   return mixin;
 }
 
-export interface PublishMixin {
-  [PUBLISHERS]: { [key: string]: Channel };
-  publish (event: string|symbol, callback: (data: any, hook: HookContext) => Channel): any;
-  registerPublisher (event: string|symbol, callback: (data: any, hook: HookContext) => Channel): any;
+export type Event = string|(typeof ALL_EVENTS);
+
+export type Publisher<T = any> = (data: T, hook: HookContext<T>) => Channel | Channel[] | void | Promise<Channel | Channel[] | void>;
+
+export interface PublishMixin<T = any> {
+  [PUBLISHERS]: { [ALL_EVENTS]?: Publisher<T>, [key: string]: Publisher<T> };
+  publish (event: Event, publisher: Publisher<T>): this;
+  registerPublisher (event: Event, publisher: Publisher<T>): this;
 }
 
 export function publishMixin () {
@@ -74,11 +78,11 @@ export function publishMixin () {
       return this.registerPublisher(...args);
     },
 
-    registerPublisher (event, callback) {
+    registerPublisher (event, publisher) {
       debug('Registering publisher', event);
 
-      if (!callback && typeof event === 'function') {
-        callback = event;
+      if (!publisher && typeof event === 'function') {
+        publisher = event;
         event = ALL_EVENTS;
       }
 
@@ -89,8 +93,7 @@ export function publishMixin () {
 
       const publishers = this[PUBLISHERS];
 
-      // @ts-ignore
-      publishers[event] = callback;
+      publishers[event] = publisher;
 
       return this;
     }