[BUG] Infinite recursion causes stack overflow for circular tuple schemas in AsyncAPIInputProcessor

[Varadraj75]

Describe the bug.

A valid AsyncAPI document containing a circular schema inside an array tuple causes Modelina to crash at runtime with:

RangeError: Maximum call stack size exceeded

The crash occurs in AsyncAPIInputProcessor.convertToInternalSchema because the recursion guard (alreadyIteratedSchemas) is not propagated when iterating over schema.items() using Array.map().

As a result, circular schemas inside tuple-based arrays are processed with a fresh recursion state on every iteration, leading to infinite recursion.

This affects both CLI and programmatic usage and can be triggered by valid real-world schemas.

Expected behavior

Modelina should safely process circular schemas (including tuple-based arrays) without crashing, using the existing recursion guard to prevent infinite recursion.

Screenshots

Not applicable — this is a runtime crash.

How to Reproduce

1. Create the following AsyncAPI document:

asyncapi: 2.6.0
info:
  title: Circular Array Crash Repro
  version: 1.0.0

channels:
  test/channel:
    publish:
      message:
        payload:
          type: array
          items:
            - $ref: '#/components/schemas/Node'
            - $ref: '#/components/schemas/Node'

components:
  schemas:
    Node:
      type: object
      properties:
        children:
          type: array
          items:
            - $ref: '#/components/schemas/Node'

2. Run Modelina programmatically:

const { TypeScriptGenerator } = require('@asyncapi/modelina');


await new TypeScriptGenerator().generate(doc);

3. Observe the runtime crash:

RangeError: Maximum call stack size exceeded

🖥️ Device Information [optional]

• Operating System (OS): macOS
• Browser: (N/A)
• Browser Version: (N/A)

👀 Have you checked for similar open issues?

• I checked and didn't find similar issue

🏢 Have you read the Contributing Guidelines?

• I have read the Contributing Guidelines

Are you willing to work on this issue ?

Yes I am willing to submit a PR!

[Varadraj75]

Hi @jonaslagoni ,

This issue is fully reproducible with the example above.
Root cause seems to be that alreadyIteratedSchemas isn’t forwarded when iterating over tuple schema.items, which disables the recursion guard and causes infinite recursion.

I can open a PR with a minimal fix (and a regression test) if this approach looks good.

Thanks!

[jonaslagoni]

Please do ✌️