Fixing issue #4950

src/config.js

@@ -17,6 +17,7 @@ import find from 'core-js/library/fn/array/find.js';
 import includes from 'core-js/library/fn/array/includes.js';
 import Set from 'core-js/library/fn/set.js';
 import { parseQS } from './url.js';
+import { mergeDeep } from './utils.js';
 
 const from = require('core-js/library/fn/array/from.js');
 const utils = require('./utils.js');
@@ -243,7 +244,7 @@ export function newConfig() {
           memo[topic] = currBidderConfig[topic];
         } else {
           if (utils.isPlainObject(currBidderConfig[topic])) {
-            memo[topic] = Object.assign({}, config[topic], currBidderConfig[topic]);
+            memo[topic] = mergeDeep({}, config[topic], currBidderConfig[topic]);
           } else {
             memo[topic] = currBidderConfig[topic];
           }

src/utils.js

@@ -1266,3 +1266,27 @@ export function compareOn(property) {
     return 0;
   }
 }
+
+export function mergeDeep(target, ...sources) {
+  if (!sources.length) return target;
+  const source = sources.shift();
+
+  if (isPlainObject(target) && isPlainObject(source)) {
+    for (const key in source) {
+      if (isPlainObject(source[key])) {
+        if (!target[key]) Object.assign(target, { [key]: {} });
+        mergeDeep(target[key], source[key]);
+      } else if (isArray(source[key])) {
+        if (!target[key]) {
+          Object.assign(target, { [key]: source[key] });
+        } else if (isArray(target[key])) {
+          target[key] = target[key].concat(source[key]);
+        }
+      } else {
+        Object.assign(target, { [key]: source[key] });
+      }
+    }
+  }
+
+  return mergeDeep(target, ...sources);
+}

test/spec/unit/core/adapterManager_spec.js

@@ -175,7 +175,7 @@ describe('adapterManager tests', function () {
         buildRequests: {
           data: 1
         },
-        test1: { speedy: true },
+        test1: { speedy: true, fun: { test: true } },
         interpretResponse: 'baseInterpret',
         afterInterpretResponse: 'anotherBaseInterpret'
       });
@@ -212,7 +212,7 @@ describe('adapterManager tests', function () {
               data: 1,
               test: 2
             },
-            { fun: { safe: true, cheap: false }, speedy: true },
+            { fun: { safe: true, cheap: false, test: true }, speedy: true },
             { amazing: true },
             'appnexusInterpret',
             'anotherBaseInterpret'
@@ -221,14 +221,14 @@ describe('adapterManager tests', function () {
             {
               data: 1
             },
-            { speedy: true },
+            { fun: { test: true }, speedy: true },
             undefined,
             'baseInterpret',
             'anotherBaseInterpret'
           ],
           'rubicon': [
             'rubiconBuild',
-            { speedy: true },
+            { fun: { test: true }, speedy: true },
             { amazing: true },
             null,
             'anotherBaseInterpret'

test/spec/utils_spec.js

@@ -922,4 +922,101 @@ describe('Utils', function () {
       });
     });
   });
+
+  describe('mergeDeep', function() {
+    it('properly merge objects that share same property names', function() {
+      const object1 = {
+        propA: {
+          subPropA: 'abc'
+        }
+      };
+      const object2 = {
+        propA: {
+          subPropB: 'def'
+        }
+      };
+
+      const resultWithoutMergeDeep = Object.assign({}, object1, object2);
+      expect(resultWithoutMergeDeep).to.deep.equal({
+        propA: {
+          subPropB: 'def'
+        }
+      });
+
+      const resultWithMergeDeep = utils.mergeDeep({}, object1, object2);
+      expect(resultWithMergeDeep).to.deep.equal({
+        propA: {
+          subPropA: 'abc',
+          subPropB: 'def'
+        }
+      });
+    });
+
+    it('properly merge objects that have different depths', function() {
+      const object1 = {
+        depth0_A: {
+          depth1_A: {
+            depth2_A: 123
+          }
+        }
+      };
+      const object2 = {
+        depth0_A: {
+          depth1_A: {
+            depth2_B: {
+              depth3_A: {
+                depth4_A: 'def'
+              }
+            }
+          },
+          depth1_B: 'abc'
+        }
+      };
+      const object3 = {
+        depth0_B: 456
+      };
+
+      const result = utils.mergeDeep({}, object1, object2, object3);
+      expect(result).to.deep.equal({
+        depth0_A: {
+          depth1_A: {
+            depth2_A: 123,
+            depth2_B: {
+              depth3_A: {
+                depth4_A: 'def'
+              }
+            }
+          },
+          depth1_B: 'abc'
+        },
+        depth0_B: 456
+      });
+    });
+
+    it('properly merge objects with various property types', function() {
+      const object1 = {
+        depth0_A: {
+          depth1_A: ['a', 'b', 'c'],
+          depth1_B: 'abc',
+          depth1_C: 123
+        }
+      };
+      const object2 = {
+        depth0_A: {
+          depth1_A: ['d', 'e', 'f'],
+          depth1_D: true,
+        }
+      };
+
+      const result = utils.mergeDeep({}, object1, object2);
+      expect(result).to.deep.equal({
+        depth0_A: {
+          depth1_A: ['a', 'b', 'c', 'd', 'e', 'f'],
+          depth1_B: 'abc',
+          depth1_C: 123,
+          depth1_D: true,
+        }
+      });
+    });
+  });
 });