Feature/event name mapping (#480)

feat(observer): introduce `eventMapping` option, allowing to extract even name from event data. Especially useful for 3rd party APIs. Kudos @amiceli for the feature

* Update readme.

* Update types/index.d.ts

Co-authored-by: Max Lyashuk <[email protected]>

README.md

@@ -397,6 +397,7 @@ Here they are:
 | `mutationPrefix` | `String` | `'SOCKET_'` | Prepend to event name while converting event to mutation. Empty string disables prefixing |  
 | `eventToMutationTransformer` | `Function` `string => string` | uppercase function | Determines how event name converted to mutation |
 | `eventToActionTransformer` | `Function` `string => string` | camelcase function | Determines how event name converted to action |
+| eventMapping | `Function` `socket => string` | | Map your event from socket event data 
 
 *FYI:* You can always access default plugin options if you need it (e.g. re-use default `eventToActionTransformer` function):
 

src/Observe.js

@@ -43,8 +43,14 @@ export default (Socket, { store, ...otherOptions } = {}) => {
   function registerEventHandler() {
     augmentMethod(Socket, 'onevent', (packet) => {
       const [eventName, ...args] = packet.data;
-      GlobalEmitter.emit(eventName, ...args);
-      passToStore(eventName, args);
+      let mappedEventName = eventName;
+
+      if (otherOptions.eventMapping) {
+        mappedEventName = otherOptions.eventMapping(eventName, args);
+      }
+
+      GlobalEmitter.emit(mappedEventName, ...args);
+      passToStore(mappedEventName, args);
     });
 
     SYSTEM_EVENTS.forEach((eventName) => {

src/__tests__/Observe.spec.js

@@ -199,6 +199,18 @@ it('should apply custom event to mutation transformer', () => {
   expect(fn).toHaveBeenLastCalledWith(store.state, expect.objectContaining(message));
 });
 
+it('should apply custom event name mapping', () => {
+  const fn = jest.fn();
+  const socket = io('wss://localhost');
+  Observe(socket, {
+    eventMapping: fn,
+  });
+  const message = { id: 15, body: 'Hi there' };
+  socket.fireServerEvent('new message', message);
+  expect(fn).toHaveBeenCalledTimes(1);
+  expect(fn).toHaveBeenLastCalledWith('new message', [message]);
+});
+
 it('should apply custom action prefix', () => {
   const fn = jest.fn();
   const store = new Store({

types/index.d.ts

@@ -9,6 +9,7 @@ export interface SocketToVuexOptions {
   mutationPrefix?: string;
   eventToMutationTransformer?: (eventName: string) => string;
   eventToActionTransformer?: (eventName: string) => string;
+  eventMapping? : (eventMapping : string, socketPayload : any[]) => string
 }
 
 export interface VueSocketIOExtOptions extends SocketToVuexOptions{