backend/e2e/fixtures.ts

/**
 * E2E test fixtures: spins up a real server on a random port with
 * mocked /api/chat and /api/embed-chat endpoints (no LLM calls).
 */
import { test as base, type Page } from "@playwright/test";
import { mkdtempSync, rmSync } from "fs";
import { join, dirname } from "path";
import { fileURLToPath } from "url";
import type { AddressInfo } from "net";
import { createApp, resetSaveTimers } from "../src/create-app.js";
import { setDataDir } from "../src/utils.js";

const __filename = fileURLToPath(import.meta.url);
const BACKEND_DIR = join(dirname(__filename), "..");

const STREAM_HEADERS = {
  "Content-Type": "text/event-stream",
  "Cache-Control": "no-cache",
  "Connection": "keep-alive",
  "X-Accel-Buffering": "no",
  "X-Vercel-AI-UI-Message-Stream": "v1",
};

function buildFakeStream(text: string): string {
  const textId = `txt-${Date.now()}`;
  const events = [
    { type: "start" },
    { type: "text-start", id: textId },
    { type: "text-delta", id: textId, delta: text },
    { type: "text-end", id: textId },
    { type: "finish-step" },
    { type: "finish" },
  ];
  const lines = events.map((e) => `data: ${JSON.stringify(e)}\n`).join("\n");
  return lines + "\ndata: [DONE]\n\n";
}

interface TestFixtures {
  serverUrl: string;
  appPage: Page;
}

export const test = base.extend<TestFixtures>({
  serverUrl: [
    async ({}, use) => {
      // Keep tmpDir under backend/ so relative staticDir path (../../frontend/dist) resolves
      const tmpDir = mkdtempSync(join(BACKEND_DIR, ".e2e-data-"));
      setDataDir(tmpDir);

      const { app, httpServer, hocuspocus } = createApp();

      await new Promise<void>((resolve) => httpServer.listen(0, resolve));
      const port = (httpServer.address() as AddressInfo).port;
      const url = `http://localhost:${port}`;

      await use(url);

      resetSaveTimers();
      try { await hocuspocus.destroy(); } catch {}
      try { httpServer.close(); } catch {}
      setDataDir(undefined);
      try { rmSync(tmpDir, { recursive: true, force: true }); } catch {}
    },
    { scope: "test" },
  ],

  appPage: async ({ page, serverUrl }, use) => {
    // Intercept chat API calls at the browser level
    await page.route("**/api/chat", async (route) => {
      await route.fulfill({
        status: 200,
        headers: STREAM_HEADERS,
        body: buildFakeStream("Hello! I'm the AI assistant."),
      });
    });

    await page.route("**/api/embed-chat", async (route) => {
      await route.fulfill({
        status: 200,
        headers: STREAM_HEADERS,
        body: buildFakeStream("Chart created successfully."),
      });
    });

    await page.goto(serverUrl);
    // Wait for editor to be ready (toolbar visible)
    await page.waitForSelector("[aria-label='Undo']", { timeout: 15_000 });
    await use(page);
  },
});

export { expect } from "@playwright/test";