refactor(core): canonicalize pty service (#32182)

packages/core/test/pty/protocol.test.ts

@@ -0,0 +1,27 @@
+import { describe, expect, test } from "bun:test"
+import { PtyProtocol } from "@opencode-ai/core/pty/protocol"
+
+describe("pty protocol", () => {
+  test("drops invalid binary input frames and decodes valid ones", () => {
+    expect(PtyProtocol.decodeInput("ready")).toBe("ready")
+    expect(PtyProtocol.decodeInput(new Uint8Array([0xff, 0xfe, 0xfd]))).toBeUndefined()
+    expect(PtyProtocol.decodeInput(new TextEncoder().encode("hello"))).toBe("hello")
+    expect(PtyProtocol.decodeInput(new TextEncoder().encode("hello").buffer)).toBe("hello")
+  })
+
+  test("encodes the cursor as a 0x00-prefixed JSON control frame", () => {
+    const frame = PtyProtocol.metaFrame(42)
+    expect(frame[0]).toBe(0)
+    expect(JSON.parse(new TextDecoder().decode(frame.subarray(1)))).toEqual({ cursor: 42 })
+  })
+
+  test("splits replay into bounded frames", () => {
+    expect(PtyProtocol.chunks("")).toEqual([])
+    expect(PtyProtocol.chunks("abc")).toEqual(["abc"])
+    const big = "x".repeat(PtyProtocol.REPLAY_CHUNK + 1)
+    const frames = PtyProtocol.chunks(big)
+    expect(frames.length).toBe(2)
+    expect(frames[0].length).toBe(PtyProtocol.REPLAY_CHUNK)
+    expect(frames.join("")).toBe(big)
+  })
+})