fix: slight change in allOf merging

Author: P0lip

src/tree/utils/mergeAllOf.ts

@@ -1,7 +1,6 @@
-import { pathToPointer } from '@stoplight/json';
+import { pathToPointer, safeStringify } from '@stoplight/json';
 import { JsonPath } from '@stoplight/types';
 import { JSONSchema4 } from 'json-schema';
-import { cloneDeep } from 'lodash';
 import { ResolvingError } from '../../errors';
 import { WalkingOptions } from './populateTree';
 
@@ -10,7 +9,7 @@ const resolveAllOf = require('@stoplight/json-schema-merge-allof');
 const store = new WeakMap<WalkingOptions, WeakMap<JSONSchema4, string[]>>();
 
 function _mergeAllOf(schema: JSONSchema4, path: JsonPath, opts: WalkingOptions) {
-  return resolveAllOf(cloneDeep(schema), {
+  return resolveAllOf(schema, {
     deep: false,
     resolvers: resolveAllOf.stoplightResolvers,
     $refResolver($ref: unknown) {
@@ -28,7 +27,8 @@ function _mergeAllOf(schema: JSONSchema4, path: JsonPath, opts: WalkingOptions)
       if (schemaRefs === void 0) {
         allRefs.set(schema, [$ref]);
       } else if (schemaRefs.includes($ref)) {
-        throw new ResolvingError('Circular reference detected');
+        const resolved = JSON.parse(safeStringify(opts.resolveRef(null, $ref)));
+        return 'allOf' in resolved ? _mergeAllOf(resolved, path, opts) : resolved;
       } else {
         schemaRefs.push($ref);
       }