fix(downgrader): follow path item refs through lowercase additionalOperations keys

packages/downgrader/src/shared.ts

@@ -803,11 +803,12 @@ export function hasDanglingOperationRef(link: unknown, ctx: Context): boolean {
 }
 
 function isOperationPointer(tokens: readonly string[]): boolean {
+  // Read from the end, an operation key can be parsed two ways:
+  // `additionalOperations` keys may be lowercase, even `query` or `get`, and a
+  // webhook or callback expression may itself be named `additionalOperations`.
   const key = tokens.at(-1) as string
-  if ((HTTP_METHODS as readonly string[]).includes(key) || key === 'query') {
-    return isPathItemPointer(tokens.slice(0, -1))
-  }
-  return tokens.at(-2) === 'additionalOperations' && isPathItemPointer(tokens.slice(0, -2))
+  return (tokens.at(-2) === 'additionalOperations' && isPathItemPointer(tokens.slice(0, -2)))
+    || (((HTTP_METHODS as readonly string[]).includes(key) || key === 'query') && isPathItemPointer(tokens.slice(0, -1)))
 }
 
 function isPathItemPointer(tokens: readonly string[]): boolean {

packages/downgrader/tests/v3.2-to-v3.1/spec/removed-parts.test.ts

@@ -298,6 +298,23 @@ describe('path Item references', () => {
     })
   })
 
+  // The 3.2 schema only forbids uppercase method names as `additionalOperations`
+  // keys, so a lowercase `query` or fixed method like `get` is a valid key
+  // there, and pointers through it still land in a removed part. A webhook may
+  // itself be named `additionalOperations`, with its own removed `query`.
+  it.each([
+    '#/paths/~1a/additionalOperations/query/callbacks/c/{$url}',
+    '#/paths/~1a/additionalOperations/get/callbacks/c/{$url}',
+    '#/webhooks/additionalOperations/query/callbacks/c/{$url}',
+  ])('inlines a path item $ref to %s', ($ref) => {
+    const callbacks = { c: { '{$url}': { description: 'inlined' } } }
+    expect(dig(convertSpec({
+      components: { pathItems: { P: { $ref } } },
+      paths: { '/a': { additionalOperations: { get: { callbacks }, query: { callbacks } } } },
+      webhooks: { additionalOperations: { query: { callbacks } } },
+    }), 'components', 'pathItems', 'P')).toEqual({ description: 'inlined' })
+  })
+
   // Only pointers that actually land on a Path Item are merged as one. An
   // extension inside a Callback Object is not a Path Item, so a `$ref` to it
   // is left as written.