packages/coding-agent/test/session.test.ts

import { readFile, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { createAgentSession, ModelRuntime, SessionManager } from "@zpi-dev/coding-agent";
import { expect, it } from "vitest";
import { demoServer, fakeConfig } from "../../../tests/fake-server.ts";
import { cleanup, directory } from "./helpers/session-fixture.ts";

it("SDK read/write/edit/bash loop persists, reopens and continues", async () => {
  const cwd = await directory();
  await writeFile(join(cwd, "README.md"), "# Temporary project");
  const s = await demoServer();
  cleanup.push(s.close);
  const runtime = await ModelRuntime.create();
  runtime.registerProvider("fake", { baseUrl: s.url, models: [fakeConfig(s.url)], apiKey: "local" });
  const manager = SessionManager.create(cwd, join(cwd, "sessions"));
  const stopMutating = manager.subscribeEntries((entry) => {
    entry.id = "mutated-observer-copy";
    if (entry.type === "message" && entry.message.role === "user") entry.message.content = "mutated";
  });
  const stopChecking = manager.subscribeEntries((entry) => {
    expect(entry.id).toBe(manager.getLastEntry()?.id);
  });
  const { session } = await createAgentSession({
    homeDir: join(cwd, "home"),
    cwd,
    agentDir: join(cwd, "agent"),
    modelRuntime: runtime,
    sessionManager: manager,
  });
  let settled = 0;
  session.subscribe((e) => {
    if (e.type === "agent_settled") settled++;
  });
  await session.prompt("go");
  expect(settled).toBe(1);
  expect(manager.buildSessionContext().messages).toContainEqual(
    expect.objectContaining({ role: "user", content: "go" }),
  );
  stopMutating();
  stopChecking();
  expect(await readFile(join(cwd, "demo.txt"), "utf8")).toBe("ZPI\n");
  expect(session.messages.filter((m) => m.role === "toolResult")).toHaveLength(4);
  session.dispose();
  const file = manager.getSessionFile() as string;
  const original = await readFile(file, "utf8");
  const reopened = SessionManager.open(file);
  expect(await readFile(file, "utf8")).toBe(original);
  const restored = await createAgentSession({
    homeDir: join(cwd, "home"),
    modelRuntime: runtime,
    sessionManager: reopened,
    agentDir: join(cwd, "agent"),
  });
  const requests = s.requests.length;
  await restored.session.prompt("continue");
  expect(s.requests.length).toBe(requests + 1);
  expect((await readFile(file, "utf8")).startsWith(original)).toBe(true);
  expect(s.requests.at(-1)?.messages).toEqual(
    expect.arrayContaining([expect.objectContaining({ role: "tool", tool_call_id: "call-3" })]),
  );
  expect(restored.session.messages.filter((m) => m.role === "system")).toEqual(
    session.messages.filter((m) => m.role === "system"),
  );
  restored.session.dispose();
});