Bug fix to populate userSync default values

src/config.js

@@ -15,12 +15,6 @@ const DEFAULT_BIDDER_TIMEOUT = 3000;
 const DEFAULT_PUBLISHER_DOMAIN = window.location.origin;
 const DEFAULT_COOKIESYNC_DELAY = 100;
 const DEFAULT_ENABLE_SEND_ALL_BIDS = false;
-const DEFAULT_USERSYNC = {
-  syncEnabled: true,
-  pixelEnabled: true,
-  syncsPerBidder: 5,
-  syncDelay: 3000
-};
 
 const GRANULARITY_OPTIONS = {
   LOW: 'low',
@@ -44,6 +38,8 @@ const ALL_TOPICS = '*';
 export function newConfig() {
   let listeners = [];
 
+  let defaults = {};
+
   let config = {
     // `debug` is equivalent to legacy `pbjs.logging` property
     _debug: DEFAULT_DEBUG,
@@ -122,10 +118,7 @@ export function newConfig() {
     // calls existing function which may be moved after deprecation
     set s2sConfig(val) {
       $$PREBID_GLOBAL$$.setS2SConfig(val);
-    },
-
-    // userSync defaults
-    userSync: DEFAULT_USERSYNC
+    }
   };
 
   function hasGranularity(val) {
@@ -177,8 +170,35 @@ export function newConfig() {
       return;
     }
 
+    let topics = Object.keys(options);
+    let topicalConfig = {};
+
+    topics.forEach(topic => {
+      let option = options[topic];
+
+      if (typeof defaults[topic] === 'object' && typeof option === 'object') {
+        option = Object.assign({}, defaults[topic], option);
+      }
+
+      topicalConfig[topic] = config[topic] = option;
+    });
+
+    callSubscribers(topicalConfig);
+  }
+
+  /**
+   * Sets configuration defaults which setConfig values can be applied on top of
+   * @param {object} options
+   */
+  function setDefaults(options) {
+    if (typeof defaults !== 'object') {
+      utils.logError('defaults must be an object');
+      return;
+    }
+
+    Object.assign(defaults, options);
+    // Add default values to config as well
     Object.assign(config, options);
-    callSubscribers(options);
   }
 
   /*
@@ -246,7 +266,8 @@ export function newConfig() {
 
   return {
     getConfig,
-    setConfig
+    setConfig,
+    setDefaults
   };
 }
 

src/userSync.js

@@ -1,6 +1,16 @@
 import * as utils from 'src/utils';
 import { config } from 'src/config';
 
+// Set userSync default values
+config.setDefaults({
+  'userSync': {
+    syncEnabled: true,
+    pixelEnabled: true,
+    syncsPerBidder: 5,
+    syncDelay: 3000
+  }
+});
+
 /**
  * Factory function which creates a new UserSyncPool.
  *

test/spec/config_spec.js

@@ -6,13 +6,15 @@ const utils = require('src/utils');
 
 let getConfig;
 let setConfig;
+let setDefaults;
 
 describe('config API', () => {
   let logErrorSpy;
   beforeEach(() => {
     const config = newConfig();
     getConfig = config.getConfig;
     setConfig = config.setConfig;
+    setDefaults = config.setDefaults;
     logErrorSpy = sinon.spy(utils, 'logError');
   });
 
@@ -86,12 +88,14 @@ describe('config API', () => {
   });
 
   it('gets default userSync config', () => {
-    expect(getConfig('userSync')).to.eql({
+    const DEFAULT_USERSYNC = {
       syncEnabled: true,
       pixelEnabled: true,
       syncsPerBidder: 5,
       syncDelay: 3000
-    });
+    };
+    setDefaults({'userSync': DEFAULT_USERSYNC});
+    expect(getConfig('userSync')).to.eql(DEFAULT_USERSYNC);
   });
 
   it('has subscribe functionality for adding listeners to config updates', () => {