feat(cli): add support for vendor-specific JSON content types in example validation (#11114)

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Author: tjb9dc

packages/cli/cli/versions.yml

@@ -1,4 +1,12 @@
 # yaml-language-server: $schema=../../../fern-versions-yml.schema.json
+- changelogEntry:
+    - summary: |
+        Add support for vendor-specific JSON content types in example validation. Content types like `application/vnd.bc.v1+json` are now accepted as valid JSON content types when validating examples against `literal<"application/json">` types.
+      type: feat
+  irVersion: 63
+  createdAt: "2025-12-09"
+  version: 3.5.0
+
 - changelogEntry:
     - summary: |
         Fix parsing of `<Code>` components with `for` attribute for synced tabs. The `for` attribute is now properly preserved when converting `<Code>` components to markdown code blocks, allowing synced tabs to work correctly across multiple `<CodeGroup>` sections.

packages/cli/generation/ir-generator/src/examples/validateTypeReferenceExample.ts

@@ -1,5 +1,5 @@
 import { FernWorkspace } from "@fern-api/api-workspace-commons";
-import { assertNever, getDuplicates, isPlainObject } from "@fern-api/core-utils";
+import { assertNever, getDuplicates, isPlainObject, MediaType } from "@fern-api/core-utils";
 import { EXAMPLE_REFERENCE_PREFIX, RawSchemas, visitRawTypeReference } from "@fern-api/fern-definition-schema";
 import {
     DoubleValidationRules,
@@ -243,7 +243,7 @@ export function validateTypeReferenceExample({
                         )(example);
                     case "string":
                         return createValidator(
-                            (e) => e === expectedLiteral.string,
+                            (e) => e === expectedLiteral.string || areMediaTypesCompatible(expectedLiteral.string, e),
                             `"${expectedLiteral.string}"`
                         )(example);
                     default:
@@ -557,3 +557,22 @@ function areLiteralTypesEquivalent({ expected, actual }: { expected: Literal; ac
             assertNever(expected);
     }
 }
+
+function areMediaTypesCompatible(expected: string, example: RawSchemas.ExampleTypeReferenceSchema): boolean {
+    if (typeof example !== "string") {
+        return false;
+    }
+
+    const expectedMediaType = MediaType.parse(expected);
+    const exampleMediaType = MediaType.parse(example);
+
+    if (expectedMediaType == null || exampleMediaType == null) {
+        return false;
+    }
+
+    if (expectedMediaType.isJSON() && exampleMediaType.isJSON()) {
+        return true;
+    }
+
+    return false;
+}