@fumari/json-schema-to-typescript cyclic reference bug

[ndom91]

To Reproduce

Since issues are disabled on fuma-nama/json-schema-to-typescript, I'll post this here.

I'm having a similar issues to here with [email protected].

The resulting OpenAPI JSON fails to be parsed and results in a maximum call stack size exceeded error when there are cyclic references like the one below:

"Butler_API_Entities_Project": {
  "type": "object",
  "properties": {
    "slug": {
      "type": "string"
    },
    "owner": {
      "type": "string"
    },
    "parent_project": {
      "$ref": "#/components/schemas/Butler_API_Entities_Project"
    },
    "name": {
      "type": "string",
      "description": "Project Name"
    },
  },
}

As you can see the parent_project property doesn't have any other fields, but the cyclic reference still rbeaks the build with the "max call stack size exceeded" error 🤔

I'm using:

"fumadocs-core": "14.4.0",
"fumadocs-mdx": "11.1.1",
"fumadocs-openapi": "^5.5.10",
"fumadocs-twoslash": "^2.0.1",
"fumadocs-ui": "14.4.0",

There is a simliar issue in the parent repository to your fork that yuo might be aware of here.

Current vs. Expected behavior

Parse openapi spec JSON successfully

Provide environment information

Node.js v22.10.0

Operating System:
  Platform: linux
  Arch: x64
  Version: #1-NixOS SMP PREEMPT_DYNAMIC Fri Nov  1 01:02:44 UTC 2024
  Available memory (MB): 32026
  Available CPU cores: 12
Binaries:
  Node: 22.10.0
  npm: 10.9.0
  Yarn: N/A
  pnpm: 9.3.0
Relevant Packages:
  next: 15.0.3 // Latest available version is detected (15.0.3).
  eslint-config-next: N/A
  react: 18.3.1
  react-dom: 18.3.1
  typescript: N/A
Next.js Config:
  output: N/A

I've worked around it so far by just dropping self-referencing properties in the effected entities before passing the json file to fumadocs-openapi's generateFiles as input.

delete swaggerContent.components.schemas.Butler_API_Entities_Project.properties.parentProject

Which area(s) are affected? (Select all that apply)

Integrations (e.g OpenAPI, Typescript DocsGen)

Additional context

No response

[fuma-nama]

Didn't have much time to work on the fork, I will look into that later.

[fuma-nama]

Also if you don't mind, you can disable it as a temporary fix:

export const openapi = createOpenAPI({
  generateTypeScriptSchema: false,
});

As the linked issue said