fix(in-progress): [bug] mcp issue - serialization bug

apps/api/src/policies/dto/create-policy.dto.spec.ts

@@ -1,6 +1,7 @@
 import { ValidationPipe } from '@nestjs/common';
 import { CreatePolicyDto } from './create-policy.dto';
 import { UpdatePolicyDto } from './update-policy.dto';
+import { UpdateVersionContentDto } from './version.dto';
 
 /**
  * Regression test for the MCP/public-API policy content serialization bug.
@@ -62,6 +63,20 @@ describe('Policy DTO content serialization (ValidationPipe)', () => {
     expect(result.content).not.toEqual([[], []]);
   });
 
+  // PATCH /v1/policies/:id/versions/:versionId (MCP: update-policy-version-content).
+  // The controller reads req.body today, but this DTO is the published body
+  // schema — if it is ever wired to @Body() its transform must survive the pipe.
+  it('preserves structured TipTap content on UpdateVersionContentDto', async () => {
+    const result = await pipe.transform(
+      { content: TIPTAP_NODES },
+      { type: 'body', metatype: UpdateVersionContentDto },
+    );
+
+    expect(result.content).toEqual(TIPTAP_NODES);
+    expect(result.content[0]).toMatchObject({ type: 'heading' });
+    expect(result.content).not.toEqual([[], []]);
+  });
+
   it('leaves content untouched when omitted on update', async () => {
     const result = await pipe.transform(
       { name: 'Renamed only' },

apps/api/src/policies/dto/version.dto.ts

@@ -42,9 +42,13 @@ export class UpdateVersionContentDto {
     type: 'array',
     items: { type: 'object', additionalProperties: true },
   })
-  @Transform(({ value }) => value) // Preserve raw JSON, don't let class-transformer mangle it
   @IsArray()
-  @Transform(({ value }) => value)
+  // Return the raw source value. Under the global ValidationPipe's implicit
+  // conversion, class-transformer coerces each TipTap node toward the reflected
+  // Array design-type of `content`, mangling `[{...}, {...}]` into `[[], []]`.
+  // The transform runs after that coercion, so `value` is already mangled —
+  // `obj.content` is the untouched original. Do not revert this to `value`.
+  @Transform(({ obj }) => obj.content)
   content: unknown[];
 }