Stack Overflow with circular schema references

[Jesperpaulsen]

Steps to reproduce

When parsing an OpenAPI 3.1.0 spec with mutually recursive (circular) schema references, swagger_parser enters infinite recursion and crashes with a Stack Overflow error.

Expected results

Shouldn't encounter stack overflow error. Either by tracking allready visited schemas or by having a max depth.

Actual results

Stack overflow error

Your OpenApi snippet

Can't share the whole snippet.

Minimal reproducer:

{
  "openapi": "3.1.0",
  "info": {"title": "Circular Ref Test", "version": "1.0.0"},
  "paths": {
    "/columns": {
      "get": {
        "operationId": "getColumns",
        "responses": {
          "200": {
            "description": "OK",
            "content": {
              "application/json": {
                "schema": {
                  "type": "array",
                  "items": {"$ref": "#/components/schemas/ColumnHeader"}
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "ColumnHeader": {
        "type": "object",
        "properties": {
          "id": {"type": "string"},
          "metadata": {
            "anyOf": [
              {"$ref": "#/components/schemas/LookupMetadata"},
              {"type": "null"}
            ]
          }
        }
      },
      "LookupMetadata": {
        "type": "object",
        "properties": {
          "target_header": {
            "anyOf": [
              {"$ref": "#/components/schemas/ColumnHeader"},
              {"type": "null"}
            ]
          }
        }
      }
    }
  }
}

Note: The minimal reproducer does not trigger the issue on its own - the stack overflow only manifests with larger specs (1000+ schemas in my case). The circular reference pattern is the root cause, but the issue may depend on spec size or specific combinations of schemas.

Code sample

Code sample

[Paste your code here]

Logs

Logs

Stack Overflow
#0      RangeError.checkValidRange (dart:core/errors.dart:375:3)
#1      _StringBase.split (dart:core-patch/string_patch.dart:991:23)
#2      NormalizedIdentifier._parseDelimitedText (package:swagger_parser/src/parser/model/normalized_identifier.dart:62:19)
#3      new NormalizedIdentifier.parse (package:swagger_parser/src/parser/model/normalized_identifier.dart:30:19)
#4      protectName (package:swagger_parser/src/parser/utils/type_utils.dart:230:47)
#5      OpenApiParser._findType (package:swagger_parser/src/parser/parser/open_api_parser.dart:2031:38)
#6      OpenApiParser._findType (package:swagger_parser/src/parser/parser/open_api_parser.dart:1771:38)
#7      OpenApiParser._findParametersAndImports (package:swagger_parser/src/parser/parser/open_api_parser.dart:808:32)
#8      OpenApiParser._getImportsAndProps (package:swagger_parser/src/parser/parser/open_api_parser.dart:2205:40)
#9      OpenApiParser._findType (package:swagger_parser/src/parser/parser/open_api_parser.dart:1885:54)
... (repeats thousands of times)

Dart version and used packages versions

Dart version

3.7

Packages version

swagger_parser: ^1.40.0

I encountered the stack overflow issue when testing the demo website as well.