Revert "fix(rivetkit): standardize error metadata return type (#3438)"

This reverts commit 0c93402.

Author: jog1t

rivetkit-typescript/packages/rivetkit/src/actor/protocol/old.ts

@@ -299,29 +299,20 @@ export async function processMessage<
 				errorData,
 				TO_CLIENT_VERSIONED,
 				ToClientSchema,
-				// JSON: metadata is the raw value (keep as undefined if not present)
-				(value): ToClientJson => {
-					const val: any = {
-						group: value.group,
-						code: value.code,
-						message: value.message,
-						actionId:
-							value.actionId !== undefined
-								? value.actionId
-								: null,
-					};
-					if (value.metadata !== undefined) {
-						val.metadata = value.metadata;
-					}
-					return {
-						body: {
-							tag: "Error" as const,
-							val,
+				// JSON: metadata is the raw value
+				(value): ToClientJson => ({
+					body: {
+						tag: "Error" as const,
+						val: {
+							group: value.group,
+							code: value.code,
+							message: value.message,
+							metadata: value.metadata ?? null,
+							actionId: value.actionId ?? null,
 						},
-					};
-				},
+					},
+				}),
 				// BARE/CBOR: metadata needs to be CBOR-encoded to ArrayBuffer
-				// Note: protocol.Error expects `| null` for optional fields (BARE protocol)
 				(value): protocol.ToClient => ({
 					body: {
 						tag: "Error" as const,
@@ -334,10 +325,7 @@ export async function processMessage<
 										cbor.encode(value.metadata),
 									)
 								: null,
-							actionId:
-								value.actionId !== undefined
-									? value.actionId
-									: null,
+							actionId: value.actionId ?? null,
 						},
 					},
 				}),

rivetkit-typescript/packages/rivetkit/src/client/utils.ts

@@ -157,7 +157,7 @@ export async function sendHttpRequest<
 					message: bare.message,
 					metadata: bare.metadata
 						? cbor.decode(new Uint8Array(bare.metadata))
-						: undefined,
+						: null,
 				}),
 			);
 		} catch (error) {

rivetkit-typescript/packages/rivetkit/src/common/router.ts

@@ -82,7 +82,7 @@ export function handleRouteError(error: unknown, c: HonoContext) {
 			group: value.group,
 			code: value.code,
 			message: value.message,
-			metadata: value.metadata,
+			metadata: value.metadata ?? null,
 		}),
 		// BARE/CBOR: metadata needs to be CBOR-encoded to ArrayBuffer
 		(value): protocol.HttpResponseError => ({

rivetkit-typescript/packages/rivetkit/src/schemas/client-protocol-zod/mod.ts

@@ -15,7 +15,7 @@ export const ErrorSchema = z.object({
 	group: z.string(),
 	code: z.string(),
 	message: z.string(),
-	metadata: z.unknown().optional(),
+	metadata: z.unknown().nullable(),
 	actionId: OptionalUintSchema,
 });
 export type Error = z.infer<typeof ErrorSchema>;
@@ -89,7 +89,7 @@ export const HttpResponseErrorSchema = z.object({
 	group: z.string(),
 	code: z.string(),
 	message: z.string(),
-	metadata: z.unknown().optional(),
+	metadata: z.unknown().nullable(),
 });
 export type HttpResponseError = z.infer<typeof HttpResponseErrorSchema>;