[8.0] [Fleet] Fix bug caused by API changes (#120886)

x-pack/plugins/fleet/server/routes/epm/index.ts

@@ -172,7 +172,8 @@ export const registerRoutes = (routers: { rbac: FleetRouter; superuser: FleetRou
         response
       );
       if (resp.payload?.item) {
-        return response.ok({ body: { response: resp.payload.item } });
+        // returning item as well here, because pkgVersion is optional in new GET endpoint, and if not specified, the router selects the deprecated route
+        return response.ok({ body: { item: resp.payload.item, response: resp.payload.item } });
       }
       return resp;
     }

x-pack/test/fleet_api_integration/apis/epm/get.ts

@@ -102,5 +102,15 @@ export default function (providerContext: FtrProviderContext) {
         .auth(testUsers.fleet_read_only.username, testUsers.fleet_read_only.password)
         .expect(200);
     });
+
+    it('returns package info in item field when calling without version', async function () {
+      // this will install through the registry by default
+      await installPackage(testPkgName, testPkgVersion);
+      const res = await supertest.get(`/api/fleet/epm/packages/${testPkgName}`).expect(200);
+      const packageInfo = res.body.item;
+      // the uploaded version will have this description
+      expect(packageInfo.name).to.equal('apache');
+      await uninstallPackage(testPkgName, testPkgVersion);
+    });
   });
 }