Add multiplexed terminal stream slots

packages/server/src/shared/terminal-stream-protocol.test.ts

@@ -11,19 +11,22 @@ import {
 } from "./terminal-stream-protocol.js";
 
 describe("terminal stream protocol", () => {
-  it("encodes output frames as a 1-byte opcode prefix plus payload", () => {
+  it("encodes output frames as opcode plus slot plus payload", () => {
     const payload = new TextEncoder().encode("hello");
     const encoded = encodeTerminalStreamFrame({
       opcode: TerminalStreamOpcode.Output,
+      slot: 7,
       payload,
     });
 
     expect(encoded[0]).toBe(TerminalStreamOpcode.Output);
-    expect(Array.from(encoded.subarray(1))).toEqual(Array.from(payload));
+    expect(encoded[1]).toBe(7);
+    expect(Array.from(encoded.subarray(2))).toEqual(Array.from(payload));
 
     const decoded = decodeTerminalStreamFrame(encoded);
     expect(decoded).toEqual({
       opcode: TerminalStreamOpcode.Output,
+      slot: 7,
       payload,
     });
   });
@@ -54,7 +57,11 @@ describe("terminal stream protocol", () => {
   });
 
   it("rejects unknown opcodes", () => {
-    expect(decodeTerminalStreamFrame(new Uint8Array([0xff, 0x01]))).toBeNull();
+    expect(decodeTerminalStreamFrame(new Uint8Array([0xff, 0x01, 0x02]))).toBeNull();
+  });
+
+  it("rejects frames without a slot byte", () => {
+    expect(decodeTerminalStreamFrame(new Uint8Array([TerminalStreamOpcode.Output]))).toBeNull();
   });
 
   it("rejects malformed JSON payloads", () => {
@@ -66,7 +73,9 @@ describe("terminal stream protocol", () => {
 
   it("rejects invalid resize and snapshot shapes", () => {
     expect(
-      decodeTerminalResizePayload(new TextEncoder().encode(JSON.stringify({ rows: "24", cols: 80 }))),
+      decodeTerminalResizePayload(
+        new TextEncoder().encode(JSON.stringify({ rows: "24", cols: 80 })),
+      ),
     ).toBeNull();
     expect(
       decodeTerminalSnapshotPayload(