コンテンツサーバの実装

2020-11-24-advent-calendar-2020-server-content-server-implementation.ts

async function contentServer(filePath: string, req: any, res: any) {
  try {
    const data = await fs.promises.readFile(`${filePath}`, "utf-8");

    const extname = String(path.extname(filePath)).toLowerCase();
    const mimeTypes = {
      ".html": "text/html",
      ".md": "text/markdown",
      ".js": "text/javascript",
      // .tsと.tsxはプロジェクトのソースを参照したい時に備えて
      ".ts": "text/plain",
      ".tsx": "text/plain",
      ".css": "text/css",
      ".json": "application/json",
      ".png": "image/png",
      ".jpg": "image/jpg",
      ".gif": "image/gif",
      ".wav": "audio/wav",
      ".mp4": "video/mp4",
      ".woff": "application/font-woff",
      ".ttf": "application/font-ttf",
      ".eot": "application/vnd.ms-fontobject",
      ".otf": "application/font-otf",
      ".svg": "application/image/svg+xml",
    } as Record<string, string>;

    const contentType = mimeTypes[extname] ?? "application/octet-stream";

    res.writeHead(200, { "Content-Type": `${contentType};charset=utf-8` });
    res.write(data);
  } catch (e) {
    res.writeHead(404);
    res.write(JSON.stringify(e));
  }
}