fix: Prevent distorted properties

Author: thim81

test/yaml-preserve-example-props/input.yaml

@@ -0,0 +1,21 @@
+openapi: 3.0.0
+info:
+  title: Repro
+paths:
+  /items:
+    get:
+      responses:
+        '200':
+          description: Successful response
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  properties:
+                    type: object
+                    text:
+                      type: string
+              example:
+                properties:
+                  text: "test"

test/yaml-preserve-example-props/options.yaml

@@ -0,0 +1,3 @@
+verbose: true
+output: output.yaml
+#no-sort: true

test/yaml-preserve-example-props/output.yaml

@@ -0,0 +1,21 @@
+openapi: 3.0.0
+info:
+  title: Repro
+paths:
+  /items:
+    get:
+      responses:
+        '200':
+          description: Successful response
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  properties:
+                    type: object
+                    text:
+                      type: string
+              example:
+                properties:
+                  text: test

utils/sorting.js

@@ -52,6 +52,9 @@ function propComparator(priorityArr) {
  * @returns {*}
  */
 function prioritySort(jsonProp, sortPriority, options) {
+  if (typeof jsonProp !== 'object' || jsonProp === null) {
+    return jsonProp;
+  }
   return sortObjectByKeyNameList(jsonProp, propComparator(sortPriority));
 }