fix: example merging

Author: P0lip

src/utils/__tests__/mergeAllOf.spec.ts

@@ -2,8 +2,80 @@ import { JSONSchema4 } from 'json-schema';
 import { mergeAllOf } from '../mergeAllOf';
 
 describe('mergeAllOf util', () => {
+  describe('example merging', () => {
+    test('given incompatible, should leave empty', () => {
+      const schema: JSONSchema4 = {
+        allOf: [
+          {
+            type: 'object',
+            properties: {
+              bar: {
+                type: 'string',
+                example: 'hello',
+              },
+            },
+          },
+          {
+            type: 'object',
+            properties: {
+              bar: {
+                type: 'string',
+                example: 'bye',
+              },
+            },
+          },
+        ],
+      };
+
+      expect(mergeAllOf(schema, [], jest.fn())).toEqual({
+        properties: {
+          bar: {
+            example: null,
+            type: 'string',
+          },
+        },
+        type: 'object',
+      });
+    });
+
+    test('given compatible, should merge normally', () => {
+      const schema: JSONSchema4 = {
+        allOf: [
+          {
+            type: 'object',
+            properties: {
+              bar: {
+                type: 'string',
+                example: 'hello',
+              },
+            },
+          },
+          {
+            type: 'object',
+            properties: {
+              bar: {
+                type: 'string',
+                example: 'hello',
+              },
+            },
+          },
+        ],
+      };
+
+      expect(mergeAllOf(schema, [], jest.fn())).toEqual({
+        properties: {
+          bar: {
+            example: 'hello',
+            type: 'string',
+          },
+        },
+        type: 'object',
+      });
+    });
+  });
+
   describe('enums merging', () => {
-    test('given incompatible, should mark enum as empty', () => {
+    test('given incompatible, should leave empty', () => {
       const schema: JSONSchema4 = {
         allOf: [
           {
@@ -38,7 +110,7 @@ describe('mergeAllOf util', () => {
       });
     });
 
-    test('given incompatible, should merge normally', () => {
+    test('given compatible, should merge normally', () => {
       const schema: JSONSchema4 = {
         allOf: [
           {

src/utils/mergeAllOf.ts

@@ -11,8 +11,15 @@ function _mergeAllOf(schema: JSONSchema4, path: JsonPath, resolveRef: WalkerRefR
   return resolveAllOf(cloneDeep(schema), {
     deep: false,
     resolvers: {
-      defaultResolver(values: any) {
-        return Object.assign({}, ...values);
+      defaultResolver(values: unknown) {
+        if (Array.isArray(values)) {
+          return values;
+        }
+
+        return Object.assign({}, ...Object(values));
+      },
+      example(values: unknown[]) {
+        return resolveAllOf.options.resolvers.enum(values) || null;
       },
       enum(values: unknown[]) {
         return resolveAllOf.options.resolvers.enum(compact(values)) || [];