fix(rivetkit): remove client-side connection request size check (#5057)

# Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [ ] This change requires a documentation update

## How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my feature works
- [ ] New and existing unit tests pass locally with my changes

Author: abcxff

rivetkit-typescript/packages/rivetkit/src/client/actor-conn.ts

@@ -93,8 +93,6 @@ interface EventSubscriptions<Args extends Array<unknown>> {
 	once: boolean;
 }
 
-const DEFAULT_MAX_INCOMING_MESSAGE_SIZE = 65_536;
-
 /**
  * A function that unsubscribes from an event.
  *
@@ -1280,34 +1278,8 @@ export class ActorConnRaw {
 							}
 						},
 					);
-					const serializedLength = messageLength(messageSerialized);
-					if (
-						serializedLength > DEFAULT_MAX_INCOMING_MESSAGE_SIZE &&
-						message.body.tag === "ActionRequest"
-					) {
-						const actionId = Number(message.body.val.id);
-						const inFlight = this.#takeActionInFlight(actionId);
-						const error = new errors.ActorError(
-							"message",
-							"incoming_too_long",
-							"Incoming message too long",
-							{
-								maxSize: DEFAULT_MAX_INCOMING_MESSAGE_SIZE,
-								actualSize: serializedLength,
-							},
-						);
-						logger().warn({
-							msg: "rejecting oversized connection action request",
-							actionId,
-							actionName: inFlight.name,
-							actualSize: serializedLength,
-							maxSize: DEFAULT_MAX_INCOMING_MESSAGE_SIZE,
-						});
-						inFlight.reject(error);
-						this.#dispatchActorError(error);
-						return;
-					}
 					this.#websocket.send(messageSerialized);
+					const serializedLength = messageLength(messageSerialized);
 					logger().trace({
 						msg: "sent websocket message",
 						len: serializedLength,

rivetkit-typescript/packages/rivetkit/tests/driver/actor-conn.test.ts

@@ -707,30 +707,48 @@ describeDriverMatrix("Actor Conn", (driverTestConfig) => {
 				await connection.dispose();
 			});
 
-			test("should reject request exceeding maxIncomingMessageSize", async (c) => {
+			test("should reject request exceeding maxIncomingMessageSize via server", async (c) => {
 				const { client } = await setupDriverTest(c, driverTestConfig);
 
 				const handle = client.largePayloadConnActor.getOrCreate([
 					"test-large-request-exceed",
 				]);
 				const connection = handle.connect();
 
-				// Create a payload that exceeds the default 64KB limit
-				// Each item is roughly 60 bytes, so 1500 items ≈ 90KB
+				// Create a payload that exceeds the default 64KB limit.
+				// Each item is roughly 60 bytes, so 1500 items ~ 90KB.
+				// The server enforces the limit and closes the entire
+				// WebSocket with reason "message.incoming_too_long".
 				const items: string[] = [];
 				for (let i = 0; i < 1500; i++) {
 					items.push(
 						`Item ${i} with some additional text to increase size`,
 					);
 				}
 
-				await expect(
-					connection.processLargeRequest({ items }),
-				).rejects.toMatchObject({
+				// Send a normal action concurrently with the oversized
+				// one to verify the server closes the whole connection,
+				// not just the offending action.
+				const [oversizedResult, collateralResult] =
+					await Promise.allSettled([
+						connection.processLargeRequest({ items }),
+						connection.processLargeRequest({
+							items: ["small"],
+						}),
+					]);
+
+				expect(oversizedResult.status).toBe("rejected");
+				expect(
+					(oversizedResult as PromiseRejectedResult).reason,
+				).toMatchObject({
 					group: "message",
 					code: "incoming_too_long",
 				});
 
+				// The normal action also fails because the server
+				// closed the connection.
+				expect(collateralResult.status).toBe("rejected");
+
 				// Clean up
 				await connection.dispose();
 			});