Add guard for when lhs is not an object to default value to rhs

Author: mattphillips

src/index.js

@@ -4,7 +4,7 @@ const isEmpty = o => Object.keys(o).length === 0;
 const diff = (lhs, rhs) => {
   if (lhs === rhs) return {};
 
-  if (!isObject(rhs) || rhs === null || lhs === null) return rhs;
+  if (!isObject(lhs) || !isObject(rhs) || rhs === null || lhs === null) return rhs;
 
   const rhsKeys = Object.keys(rhs);
 

src/index.spec.js

@@ -29,7 +29,8 @@ describe('.diff', () => {
         ['hello', undefined],
         [null, undefined],
         [undefined, null],
-        [null, { a: 1 }]
+        [null, { a: 1 }],
+        ['872983', { areaCode: '+44', number: '872983' }]
       ]).it('returns right hand side value when different to left hand side value (%s, %s)', (lhs, rhs) => {
         expect(diff(lhs, rhs)).to.deep.equal(rhs);
       });