Stop infinite renders caused by circular $ref object properties

[heath-freenome]

Reasons for making this change

Fixes #3907 and #4262

• Adds RJSF_REF_CYCLE_KEY ('__rjsf_ref_cycle') to detect and terminate self-referential schemas that would otherwise render infinitely.
• In resolveAllReferences, when a $ref is encountered that's already in the recurseList AND we're resolving in simple (non-resolveAnyOfOrOneOfRefs) mode, the schema is tagged with __rjsf_ref_cycle: true instead of silently returning the unresolved $ref. This only fires in a direct object-property context (!resolveAnyOfOrOneOfRefs), where rendering is unconditional and cycles are genuinely infinite. Array-items and anyOf/oneOf contexts remain untagged since they are data-driven and terminate naturally.
• SchemaField checks _schema[RJSF_REF_CYCLE_KEY] after its useCallback hook (to satisfy React rules of hooks) and renders a CyclicSchemaField instead of recursing. CyclicSchemaField renders the CyclicSchemaExpandTemplate, which shows the user a message and an expand button to load the next cycle break.
• hashForSchema now filters out keys starting with RJSF_REF_KEY before hashing so that internal cycle-tracking metadata does not affect the computed hash.
• CyclicSchemaExpandTemplate is implemented for all theme packages: antd, chakra-ui, daisyui, fluentui-rc, mantine, mui, primereact, react-bootstrap, semantic-ui, and shadcn, each using their native UI library components.
• Updated snapshots for the new tests

Checklist

• I'm updating documentation
  • I've checked the rendering of the Markdown text I've added
• I'm adding or updating code
  • I've added and/or updated tests. I've run npx nx run-many --target=build --exclude=@rjsf/docs && npm run test:update to update snapshots, if needed.
  • I've updated docs if needed
  • I've updated the changelog with a description of the PR
• I'm adding a new feature
  • I've updated the playground with an example use of the feature

Preview

Screen.Recording.2026-06-07.at.8.00.42.PM.mov

[x0k]

1. In the video, clicking the button adds two fields.
2. If the initial data is {"child":{"child":{"child":{"child":{}}}}}, only two levels are rendered, plus an expand button.

In SJSF, I tried to solve this problem by generating a schemaLocation for each field in order to detect cycles at the form level (rather than in utils), but so far I have not found a simple way to guarantee correct JSON Pointer generation in all cases (then/else, dependencies, etc.).

[heath-freenome]

1. In the video, clicking the button adds two fields.

   2. If the initial data is {"child":{"child":{"child":{"child":{}}}}}, only two levels are rendered, plus an expand button.

In SJSF, I tried to solve this problem by generating a schemaLocation for each field in order to detect cycles at the form level (rather than in utils), but so far I have not found a simple way to guarantee correct JSON Pointer generation in all cases (then/else, dependencies, etc.).

Hi @x0k... Yeah it's not until we encounter the second instance of the same key that the cycle is detected, hence the information showing up 2x for each cycle since the marker is on that second item. I've been debating doing something with the recursion such that upon the cycle detection, I can somehow go back to the first instance and mark that one instead. I may spend some more time on that once this gets merged

[x0k]

hashForSchema now filters out keys starting with RJSF_REF_KEY before hashing so that internal cycle-tracking metadata does not affect the computed hash.

FYI, if you use Symbols, such keys are automatically ignored by JSON.stringify.