event emitter implementation

Author: wangshijun

packages/ocap-js/package.json

@@ -21,7 +21,8 @@
     "debug": "^3.1.0",
     "graphql": "^0.13.2",
     "phoenix": "^1.3.4",
-    "phoenix-channels": "^1.0.0"
+    "phoenix-channels": "^1.0.0",
+    "wolfy87-eventemitter": "^5.2.5"
   },
   "devDependencies": {
     "babel-cli": "^6.26.0",

packages/ocap-js/src/base.js

@@ -1,5 +1,4 @@
 const axios = require('axios');
-const EventEmitter = require('events');
 const { print, parse } = require('graphql');
 const {
   getQueryBuilders,
@@ -57,6 +56,10 @@ class OCAPClientBase {
     throw new Error('_getSocketImplementation must be implemented in sub class');
   }
 
+  _getEventImplementation() {
+    throw new Error('_getEventImplementation must be implemented in sub class');
+  }
+
   _getQueryId() {
     throw new Error('_getQueryId must be implemented in sub class');
   }
@@ -143,6 +146,7 @@ class OCAPClientBase {
               debug('subscription success', { queryId, res });
 
               // create a new EventEmitter for each subscription
+              const EventEmitter = this._getEventImplementation();
               this.subscriptions[queryId] = new EventEmitter();
               this.subscriptions[queryId].subscriptionId = res.subscriptionId;
 

packages/ocap-js/src/browser.js

@@ -1,5 +1,6 @@
 const schemas = require('@arcblock/ocap-schema');
 const md5 = require('blueimp-md5');
+const EventEmitter = require('wolfy87-eventemitter');
 const { Socket } = require('phoenix');
 const OCAPClientBase = require('./base');
 
@@ -16,6 +17,10 @@ class OCAPBrowserClient extends OCAPClientBase {
     return Socket;
   }
 
+  _getEventImplementation() {
+    return EventEmitter;
+  }
+
   /**
    * Get ignored field lists that need to be excluded when build graphql queries
    * These fields are ignored because they may cause query failure

packages/ocap-js/src/node.js

@@ -1,5 +1,6 @@
 const schemas = require('@arcblock/ocap-schema');
 const md5 = require('blueimp-md5');
+const EventEmitter = require('events');
 const { Socket } = require('phoenix-channels');
 const OCAPClientBase = require('./base');
 
@@ -16,6 +17,10 @@ class OCAPClient extends OCAPClientBase {
     return Socket;
   }
 
+  _getEventImplementation() {
+    return EventEmitter;
+  }
+
   /**
    * Get ignored field lists that need to be excluded when build graphql queries
    * These fields are ignored because they may cause query failure

packages/ocap-js/yarn.lock

@@ -4060,6 +4060,10 @@ window-size@0.1.0:
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/window-size/-/window-size-0.1.0.tgz#5438cd2ea93b202efa3a19fe8887aee7c94f9c9d"
 
+wolfy87-eventemitter@^5.2.5:
+  version "5.2.5"
+  resolved "https://registry.yarnpkg.com/wolfy87-eventemitter/-/wolfy87-eventemitter-5.2.5.tgz#e7af2adbb84e481c65edeb2a2e01032c8ff1b88f"
+
 wordwrap@0.0.2:
   version "0.0.2"
   resolved "https://registry.yarnpkg.com/wordwrap/-/wordwrap-0.0.2.tgz#b79669bb42ecb409f83d583cad52ca17eaa1643f"