Merge pull request #13940 from k-chop/backport-to-6-ismodified-acccept-string-of-keys

Backport document.isModified fix #13674 to 6.x

Author: vkarpov15

lib/document.js

@@ -2227,7 +2227,7 @@ Document.prototype.isModified = function(paths, modifiedPaths) {
     }
 
     if (typeof paths === 'string') {
-      paths = [paths];
+      paths = paths.indexOf(' ') === -1 ? [paths] : paths.split(' ');
     }
 
     for (const path of paths) {

test/document.modified.test.js

@@ -176,6 +176,22 @@ describe('document modified', function() {
       assert.equal(post.isModified('title'), false);
     });
 
+    it('should support passing a string of keys separated by a blank space as the first argument', function() {
+      const post = new BlogPost();
+      post.init({
+        title: 'Test',
+        slug: 'test',
+        date: new Date()
+      });
+
+      assert.equal(post.isModified('title'), false);
+      post.set('title', 'modified title');
+      assert.equal(post.isModified('title'), true);
+      assert.equal(post.isModified('slug'), false);
+      assert.equal(post.isModified('title slug'), true);
+    });
+
+
     describe('on DocumentArray', function() {
       it('work', function() {
         const post = new BlogPost();