hotfix: skip when mapping is not a mapping ref

Author: tatomyr

packages/core/src/__tests__/bundle.test.ts

@@ -490,6 +490,38 @@ describe('bundle', () => {
     expect(problems).toHaveLength(0);
     expect(res.parsed).toMatchSnapshot();
   });
+
+  it('should bundle discriminator with defaultMapping and mapping as component names to the same document', async () => {
+    const document = outdent`
+      openapi: 3.2.0
+      components:
+        schemas:
+          Pet:
+            type: object
+            discriminator:
+              propertyName: kind
+              defaultMapping: Cat
+              mapping:
+                cat: Cat
+          Cat:
+            type: object
+            properties:
+              kind:
+                type: string
+
+    `;
+
+    const {
+      bundle: { parsed },
+      problems,
+    } = await bundleFromString({
+      source: document,
+      config: await createConfig({}),
+    });
+
+    expect(problems).toMatchInlineSnapshot(`[]`);
+    expect(parsed).toMatchInlineSnapshot(document);
+  });
 });
 
 describe('bundleFromString', () => {

packages/core/src/bundle/bundle-visitor.ts

@@ -7,6 +7,7 @@ import {
   isRef,
   refBaseName,
   type Location,
+  isMappingRef,
 } from '../ref-utils.js';
 import { type ResolvedRefMap, type Document } from '../resolve.js';
 import { reportUnresolvedRef } from '../rules/common/no-unresolved-refs.js';
@@ -208,7 +209,12 @@ export function makeBundleVisitor({
     const componentType = mapTypeToComponent('Schema', version)!;
     visitor.Discriminator = {
       leave(discriminator: Oas3Discriminator, ctx: UserContext) {
-        if (typeof discriminator.defaultMapping !== 'string') return;
+        if (
+          typeof discriminator.defaultMapping !== 'string' ||
+          !isMappingRef(discriminator.defaultMapping)
+        ) {
+          return;
+        }
 
         const resolved = ctx.resolve({ $ref: discriminator.defaultMapping });
         if (!resolved.location || resolved.node === undefined) {
@@ -222,6 +228,9 @@ export function makeBundleVisitor({
         leave(mapping, ctx) {
           for (const name of Object.keys(mapping)) {
             const $ref = mapping[name];
+            if (!isMappingRef($ref)) {
+              continue;
+            }
             const resolved = ctx.resolve({ $ref });
             if (!resolved.location || resolved.node === undefined) {
               reportUnresolvedRef(resolved, ctx.report, ctx.location.child(name));