fix(app): terminal pty isolation

packages/opencode/test/pty/pty-output-isolation.test.ts

@@ -0,0 +1,54 @@
+import { describe, expect, test } from "bun:test"
+import { Instance } from "../../src/project/instance"
+import { Pty } from "../../src/pty"
+import { tmpdir } from "../fixture/fixture"
+
+describe("pty", () => {
+  test("does not leak output when websocket objects are reused", async () => {
+    await using dir = await tmpdir({ git: true })
+
+    await Instance.provide({
+      directory: dir.path,
+      fn: async () => {
+        const a = await Pty.create({ command: "cat", title: "a" })
+        const b = await Pty.create({ command: "cat", title: "b" })
+        try {
+          const outA: string[] = []
+          const outB: string[] = []
+
+          const ws = {
+            readyState: 1,
+            send: (data: unknown) => {
+              outA.push(typeof data === "string" ? data : Buffer.from(data as Uint8Array).toString("utf8"))
+            },
+            close: () => {
+              // no-op (simulate abrupt drop)
+            },
+          }
+
+          // Connect "a" first with ws.
+          Pty.connect(a.id, ws as any)
+
+          // Now "reuse" the same ws object for another connection.
+          ws.send = (data: unknown) => {
+            outB.push(typeof data === "string" ? data : Buffer.from(data as Uint8Array).toString("utf8"))
+          }
+          Pty.connect(b.id, ws as any)
+
+          // Clear connect metadata writes.
+          outA.length = 0
+          outB.length = 0
+
+          // Output from a must never show up in b.
+          Pty.write(a.id, "AAA\n")
+          await Bun.sleep(100)
+
+          expect(outB.join("")).not.toContain("AAA")
+        } finally {
+          await Pty.remove(a.id)
+          await Pty.remove(b.id)
+        }
+      },
+    })
+  })
+})