fix: use examples set next to a schema $ref in generated samples

[ybai08]

What/Why/How?

Since OpenAPI 3.1 a Schema Object $ref can have sibling keywords, and Redoc's schema view already shows them. Generated samples did not: openapi-sampler follows the $ref and drops its siblings, so for

Min:
  $ref: '#/components/schemas/ExampleNumber'
  example: 10
Max:
  $ref: '#/components/schemas/ExampleNumber'
  examples: [55]

the sample was { "Min": 0, "Max": 0 } instead of { "Min": 10, "Max": 55 }.

applyActiveVariantsToSchema already prepares the schema store for the sampler. When a $ref node has an example or examples sibling, it now replaces the node with its siblings, plus the target's type, xml, readOnly and writeOnly. The sampler then uses the sibling value. The XML element name and read-only/write-only filtering stay the same as when it follows the $ref. Siblings take precedence, as in the schema view. A $ref without an example sibling is left as it is.

Reference

Fixes #2609

Tests

• New cases in src/jotai/__tests__/examples.test.ts: example/examples siblings on properties (JSON and XML samples), and an example next to a $ref at the schema root. Without the change to discriminator.ts, all three fail ({ min: 0, max: 0, step: 0 }, <min>0</min>, 0).
• The suite was run on Node 22: npx vitest run gives 290 files passed, 1 skipped (3289 tests passed). npm run lint and npm run ts:check pass.
• Not run: npm run e2e (Playwright) and npm run build.

Screenshots (optional)

Check yourself

• Code is linted
• Tested
• All new/updated code is covered with tests

[AlexVarchuk]

Hi @ybai08, we'll fix it in openapi-sampler instead of adding additional complexity to the Redoc logic.

[ybai08]

Makes sense, thanks. Closing this in favour of a fix in openapi-sampler; happy to send that PR there if it would help.

[AlexVarchuk]

here is a fix in openapi-sampler Redocly/openapi-sampler#224