Function runEmbeddedMode

packages/cli/src/commands/preview.ts:835–975

* Embedded mode: serve the pre-built studio SPA with a standalone Hono server. * Works without any additional dependencies — the studio is bundled in dist/. * * If an existing HyperFrames server for the same project is detected, * reuses it instead of starting a new one (unless --force-new is se

(
  dir: string,
  startPort: number,
  options?: EmbeddedStudioOptions,
)

 * reuses it instead of starting a new one (unless --force-new is set).
 */
async function runEmbeddedMode(
  dir: string,
  startPort: number,
  options?: EmbeddedStudioOptions,
): Promise<void> {
  const { createStudioServer, loadPreviewServerBuildSignature, resolveStudioBundle } =
    await import("../server/studioServer.js");

  const pName = options?.projectName ?? basename(dir);
  const studioBundle = resolveStudioBundle();

  clack.intro(c.bold("hyperframes preview"));
  const s = clack.spinner();
  s.start("Starting studio...");

  if (!studioBundle.available) {
    s.stop(c.error("Studio build missing"));
    console.error();
    console.error(`  ${c.dim("Could not find")} ${c.accent("index.html")} ${c.dim("in:")}`);
    for (const checkedPath of studioBundle.checkedPaths) {
      console.error(`  ${c.dim("-")} ${checkedPath}`);
    }
    console.error();
    console.error(`  ${c.dim("Rebuild the CLI package with")} ${c.accent("bun run build")}`);
    console.error();
    process.exitCode = 1;
    return;
  }

  const { app } = createStudioServer({ projectDir: dir, projectName: pName });
  const serverBuildSignature = await loadPreviewServerBuildSignature();

  let result: FindPortResult;
  try {
    result = await findPortAndServe(
      app.fetch,
      startPort,
      dir,
      !!options?.forceNew,
      serverBuildSignature,
    );
  } catch (err: unknown) {
    s.stop(c.error("Failed to start studio"));
    console.error();
    console.error(`  ${(err as Error).message}`);
    console.error();
    process.exitCode = 1;
    return;
  }

  if (result.type === "already-running") {
    const url = `http://localhost:${result.port}`;
    s.stop(c.success("Already running"));
    printStudioSummary(pName, url, {
      details: ["Reusing existing server. Use --force-new to start a fresh instance."],
    });
    openStudioBrowser(url, pName, options);
    return;