Fix inlining of references to external files

packages/downgrader/src/shared.test.ts

@@ -618,6 +618,13 @@ describe('downgrade', () => {
     })
   })
 
+  it('inlines a reference whose target is itself an external reference', () => {
+    expect(convertDocument({
+      items: [{ $ref: '#/removed/a' }],
+      removed: { a: { $ref: 'other.json#/a' } },
+    }).out).toEqual({ items: [{ $ref: 'other.json#/a' }] })
+  })
+
   it('leaves missing, external, anchor, and malformed references as written', () => {
     const items = [{ $ref: '#/missing' }, { $ref: 'other.json#/a' }, { $ref: '#anchor' }, { $ref: '#/%E0%A4%A' }]
     expect(convertDocument({ items }).out).toEqual({ items })
@@ -669,9 +676,11 @@ describe('downgrade', () => {
     })
   })
 
-  it('keeps a loop of aliases as written', () => {
+  it('keeps a loop of aliases as written, even in a removed part', () => {
+    const items = [{ $ref: '#/named/a' }, { $ref: '#/removed/a' }]
     const named = { a: { $ref: '#/named/b' }, b: { $ref: '#/named/a' } }
-    expect(convertDocument({ items: [{ $ref: '#/named/a' }], named }).out).toEqual({ items: [{ $ref: '#/named/a' }], named })
+    const removed = { a: { $ref: '#/removed/b' }, b: { $ref: '#/removed/a' } }
+    expect(convertDocument({ items, named, removed }, ['#/removed/']).out).toEqual({ items, named })
   })
 
   it('removes references to removed targets, cascading through aliases', () => {

packages/downgrader/src/shared.ts

@@ -417,9 +417,8 @@ export function downgrade(root: unknown, convert: Convert, removed: readonly str
     return end
   }
   const isInlinable = (ref: string): boolean => {
-    const end = aliasEnd(ref)
-    const target = end === undefined ? undefined : resolveRef(end)
-    return isRecord(target) || typeof target === 'boolean'
+    const target = resolveRef(ref)
+    return (isRecord(target) || typeof target === 'boolean') && aliasEnd(ref) !== undefined
   }
   const dangling = new Set<string>()
   const isRemovedPart = (ref: string): boolean => removed.some(prefix => ref.startsWith(prefix))

packages/downgrader/src/v3.1-to-v3.0.test.ts

@@ -202,6 +202,15 @@ describe('downgradeSpecV31ToV30', () => {
       ).toEqual({ '/a': { ...inlined, description: 'alias', summary: 'Own' } })
     })
 
+    it('inlines an entry that references an external file', () => {
+      expect(
+        convertWithPathItems(
+          { '/a': { $ref: '#/components/pathItems/External', summary: 'Own' } },
+          { External: { $ref: './paths/a.yaml' } },
+        ).paths,
+      ).toEqual({ '/a': { $ref: './paths/a.yaml', summary: 'Own' } })
+    })
+
     it('inlines references inside callbacks', () => {
       expect(
         convertWithPathItems(
@@ -2214,6 +2223,13 @@ describe('downgradeSchemaV31ToV30', () => {
       expect(convertSchema({ $defs: { a: { type: 'string' } }, items: { $ref: '#/$defs/a' }, type: 'array' })).toEqual({ items: { type: 'string' }, type: 'array' })
     })
 
+    it('inlines $refs into $defs entries that reference an external file', () => {
+      expect(convertSchema({
+        $defs: { pet: { $ref: './schemas/pet.yaml' } },
+        properties: { pet: { $ref: '#/$defs/pet' } },
+      })).toEqual({ properties: { pet: { $ref: './schemas/pet.yaml' } } })
+    })
+
     it('inlines a $ref to items removed beside prefixItems instead of the items placeholder', () => {
       expect(convertSchema({
         properties: {

packages/downgrader/src/v3.2-to-v3.1.test.ts

@@ -1621,15 +1621,17 @@ describe('downgradeSpecV32ToV31', () => {
       const result = convertSpec({
         components: {
           parameters: {
+            External: { $ref: '#/paths/~1a/get/parameters/1' },
             Kept: { $ref: '#/paths/~1b/get/parameters/0' },
-            Shifted: { $ref: '#/paths/~1a/get/parameters/1' },
+            Shifted: { $ref: '#/paths/~1a/get/parameters/2' },
           },
         },
         paths: {
           '/a': {
             get: {
               parameters: [
                 { in: 'querystring', name: 'qs' },
+                { $ref: './parameters/limit.yaml' },
                 { in: 'query', name: 'b' },
               ],
               responses: {},
@@ -1640,11 +1642,13 @@ describe('downgradeSpecV32ToV31', () => {
       })
       expect(result.components).toEqual({
         parameters: {
+          External: { $ref: './parameters/limit.yaml' },
           Kept: { $ref: '#/paths/~1b/get/parameters/0' },
           Shifted: { in: 'query', name: 'b' },
         },
       })
       expect(dig(result, 'paths', '/a', 'get', 'parameters')).toEqual([
+        { $ref: './parameters/limit.yaml' },
         { in: 'query', name: 'b' },
       ])
     })