Function buildPreviewWrapperPackage

apps/cli/src/build.ts:655–713

(targets: Target[])

};

const buildPreviewWrapperPackage = async (targets: Target[]) => {
  const meta = await readMetadata();
  const cdnUrl = process.env.EXECUTOR_PREVIEW_CDN_URL?.replace(/\/+$/, "");
  const sha = process.env.EXECUTOR_PREVIEW_SHA;
  if (!cdnUrl || !sha) {
    throw new Error(
      "preview build requires EXECUTOR_PREVIEW_CDN_URL and EXECUTOR_PREVIEW_SHA to be set",
    );
  }

  const wrapperDir = join(distDir, meta.name);
  const binDir = join(wrapperDir, "bin");
  await mkdir(binDir, { recursive: true });

  await writeFile(join(binDir, "executor"), NODE_SHIM);
  await chmod(join(binDir, "executor"), 0o755);

  const postinstall = PREVIEW_POSTINSTALL_SCRIPT.replaceAll("__CDN_BASE_URL__", `${cdnUrl}/${sha}`);
  await writeFile(join(wrapperDir, "postinstall.cjs"), postinstall);

  // Restrict os/cpu to platforms we actually built this run so npm refuses
  // the install on anything else — a clear error beats a cryptic 404 from
  // postinstall on an unbuilt platform.
  const osList = Array.from(new Set(targets.map((t) => t.os)));
  const cpuList = Array.from(new Set(targets.map((t) => t.arch)));

  await writeFile(
    join(wrapperDir, "package.json"),
    JSON.stringify(
      {
        name: meta.name,
        version: meta.version,
        description: meta.description,
        keywords: meta.keywords,
        homepage: meta.homepage,
        bugs: meta.bugs,
        repository: meta.repository,
        license: meta.license,
        bin: { executor: "bin/executor" },
        files: ["bin", "postinstall.cjs", "README.md"],
        scripts: { postinstall: "node ./postinstall.cjs" },
        os: osList,
        cpu: cpuList,
        engines: { node: ">=20" },
      },
      null,
      2,
    ) + "\n",
  );

  const readmePath = join(repoRoot, "README.md");
  if (existsSync(readmePath)) {
    await cp(readmePath, join(wrapperDir, "README.md"));
  }

  console.log(`\nPreview wrapper: ${wrapperDir}`);
  console.log(`  ${meta.name}@${meta.version} — CDN ${cdnUrl}/${sha}`);
  console.log(`  targets: ${targets.map(targetPackageName).join(", ")}`);