libs/converter-openapi/README.md disagrees with the converter on x-adc-labels path level and x-adc-plugins splitting

[kayx23]

The libs/converter-openapi/README.md table of supported extension fields disagrees with the actual converter implementation in two places. Both make the README claim more capability than the code delivers, which silently misleads users.

1. x-adc-labels is documented as Path-Level but the schema does not allow it there

The README (table row, current main) lists x-adc-labels as supported at Root Level, Path Level, Operation Level.

The Zod schema only defines x-adc-labels on the root document and on each operation object — there is no entry for it on the path object:

https://github.com/api7/adc/blob/main/libs/converter-openapi/src/schema.ts#L58-L75

paths: z.record(
  z.string(),
  z.looseObject({
    [ExtKey.PLUGINS]: xPluginsSchema,
    // [ExtKey.PLUGIN_PREFIX]: ignore
    [ExtKey.SERVICE_DEFAULTS]: xDefaults,
    [ExtKey.UPSTREAM_DEFAULTS]: xDefaults,
    [ExtKey.ROUTE_DEFAULTS]: xDefaults,
    get: pathOperationSchema,
    put: pathOperationSchema,
    // ...
  }),
),

The path-level object is z.looseObject so the field passes schema validation silently, but src/index.ts never reads operations[ExtKey.LABELS] when iterating paths — only root (oas[ExtKey.LABELS] at line 44) and operation (operation[ExtKey.LABELS] at line 95) are mapped through. Path-level x-adc-labels is silently dropped at conversion time.

Repro: add x-adc-labels: { foo: bar } directly under a path in any test fixture, run convert, and observe the labels do not appear on any route or service in the output.

2. x-adc-plugins at Path/Operation level is documented as causing a service split, but it does not

The README (table row) says:

Plugin objects at the Path level and Operation level will cause the service to be split, i.e. the sub-level containing the plugin will be included in a new service.

The actual splitting logic in src/parser.ts only triggers parseSeprateService when one of x-adc-service-defaults, x-adc-upstream-defaults, or a sub-level servers: entry is present:

https://github.com/api7/adc/blob/main/libs/converter-openapi/src/parser.ts#L60-L65

if (
  context &&
  (context[ExtKey.SERVICE_DEFAULTS] ||
    context[ExtKey.UPSTREAM_DEFAULTS] ||
    context.servers)
) {

Plugins are absent from that condition. In src/index.ts, plugins at the path and operation level are merged into route.plugins directly (lines 82-85, 102) without invoking parseSeprateService or producing a new service. Test fixtures test/assets/extension-5.yaml and extension-6.yaml confirm this — plugins at every level produce a single service in the output, not multiple.

Suggested README changes

1. Remove the Path Level row from x-adc-labels, leaving only Root and Operation. (If path-level labels should be supported, that's a feature gap in schema.ts and index.ts rather than a README fix.)
2. Remove the "will cause the service to be split" sentence from the x-adc-plugins row description. The "Extension Fields processing logic" section already correctly describes how plugins are attached to routes without mentioning splitting; the table description just needs to match.

Happy to send a PR if helpful — let me know if either of these is actually intended behavior that I'm misreading from the source, in which case the code is the side that needs adjusting.

---

Context: discovered while writing documentation in api7/docs#1638 and verifying every claim against the source. The two corrections have already landed in the downstream docs; filing here so the upstream README stops misleading the next person.

[kayx23]

While reviewing the rest of the table I found a third inaccuracy of the same shape:

x-adc-route-defaults is documented as causing the service to be split ("This field on sub-levels will cause the service to be split."), but the splitting checklist in parseSeprateService (src/parser.ts lines 60-65) only includes SERVICE_DEFAULTS, UPSTREAM_DEFAULTS, and sub-level servers:. ROUTE_DEFAULTS is merged into each route via structuredClone spreads in src/index.ts lines 103-105 (root → path → operation order, operation wins).

Verified against the existing fixture test/assets/extension-7.yaml: the GET service split there is caused by an operation-level servers: block, not by x-adc-route-defaults; the PUT operation keeps the merged route-defaults on the main service without splitting.

PR #447 has been amended to fix this row as well.