fix: preserve unknown fields value (#3314)

packages/netlify-cms-core/src/components/Editor/__tests__/Editor.spec.js

@@ -203,7 +203,7 @@ describe('Editor', () => {
       <Editor
         {...props}
         entryDraft={fromJS({ entry: { mediaFiles: [{ id: '1' }] } })}
-        entry={fromJS({ isFetching: false })}
+        entry={fromJS({ isFetching: false, data: {} })}
         hasChanged={true}
       />,
     );
@@ -232,7 +232,7 @@ describe('Editor', () => {
           entry: {},
           fieldsMetaData: {},
         })}
-        entry={fromJS({ isFetching: false, mediaFiles: [{ id: '1' }] })}
+        entry={fromJS({ isFetching: false, mediaFiles: [{ id: '1' }], data: {} })}
       />,
     );
 

packages/netlify-cms-core/src/formats/helpers.js

@@ -1,12 +1,7 @@
 export const sortKeys = (sortedKeys = []) => (a, b) => {
   const idxA = sortedKeys.indexOf(a);
   const idxB = sortedKeys.indexOf(b);
-  if (idxA === -1 || idxB === -1) {
-    if (a > b) return 1;
-    if (a < b) return -1;
-    return 0;
-  }
-
+  if (idxA === -1 || idxB === -1) return 0;
   if (idxA > idxB) return 1;
   if (idxA < idxB) return -1;
   return 0;

packages/netlify-cms-core/src/lib/__tests__/serializeEntryValues.spec.js

@@ -0,0 +1,21 @@
+import { serializeValues, deserializeValues } from '../serializeEntryValues';
+import { fromJS } from 'immutable';
+
+const values = fromJS({ title: 'New Post', unknown: 'Unknown Field' });
+const fields = fromJS([{ name: 'title', widget: 'string' }]);
+
+describe('serializeValues', () => {
+  it('should retain unknown fields', () => {
+    expect(serializeValues(values, fields)).toEqual(
+      fromJS({ title: 'New Post', unknown: 'Unknown Field' }),
+    );
+  });
+});
+
+describe('deserializeValues', () => {
+  it('should retain unknown fields', () => {
+    expect(deserializeValues(values, fields)).toEqual(
+      fromJS({ title: 'New Post', unknown: 'Unknown Field' }),
+    );
+  });
+});

packages/netlify-cms-core/src/lib/serializeEntryValues.js

@@ -27,7 +27,7 @@ const runSerializer = (values, fields, method) => {
    * registered serializers.  If the field is a list or object, call recursively
    * for nested fields.
    */
-  return fields.reduce((acc, field) => {
+  let serializedData = fields.reduce((acc, field) => {
     const fieldName = field.get('name');
     const value = values.get(fieldName);
     const serializer = getWidgetValueSerializer(field.get('widget'));
@@ -58,6 +58,11 @@ const runSerializer = (values, fields, method) => {
 
     return acc;
   }, Map());
+
+  //preserve unknown fields value
+  serializedData = values.mergeDeep(serializedData);
+
+  return serializedData;
 };
 
 export const serializeValues = (values, fields) => {