refactor: clean up gallery tooling and document the workflow

scripts/serve.js

@@ -0,0 +1,131 @@
+const fs = require("fs");
+const http = require("http");
+const path = require("path");
+
+const { repoRoot } = require("./lib/meals");
+
+const DEFAULT_HOST = "127.0.0.1";
+const DEFAULT_PORT = 4321;
+const MIME_TYPES = {
+  ".css": "text/css; charset=utf-8",
+  ".gif": "image/gif",
+  ".html": "text/html; charset=utf-8",
+  ".ico": "image/x-icon",
+  ".jpg": "image/jpeg",
+  ".js": "application/javascript; charset=utf-8",
+  ".json": "application/json; charset=utf-8",
+  ".map": "application/json; charset=utf-8",
+  ".mp3": "audio/mpeg",
+  ".png": "image/png",
+  ".svg": "image/svg+xml",
+  ".ttf": "font/ttf",
+  ".txt": "text/plain; charset=utf-8",
+  ".webmanifest": "application/manifest+json; charset=utf-8",
+  ".woff": "font/woff",
+  ".woff2": "font/woff2",
+};
+
+function parseArgs(argv) {
+  const options = {
+    host: process.env.HOST || DEFAULT_HOST,
+    port: Number.parseInt(process.env.PORT || String(DEFAULT_PORT), 10),
+  };
+
+  for (let index = 0; index < argv.length; index += 1) {
+    const arg = argv[index];
+    const value = argv[index + 1];
+
+    if (arg === "--host" && value) {
+      options.host = value;
+      index += 1;
+      continue;
+    }
+
+    if (arg === "--port" && value) {
+      options.port = Number.parseInt(value, 10);
+      index += 1;
+    }
+  }
+
+  if (!Number.isInteger(options.port) || options.port <= 0 || options.port > 65535) {
+    throw new Error("Port must be an integer between 1 and 65535");
+  }
+
+  return options;
+}
+
+function getContentType(filePath) {
+  return MIME_TYPES[path.extname(filePath).toLowerCase()] || "application/octet-stream";
+}
+
+function resolveRequestPath(requestUrl) {
+  const url = new URL(requestUrl, "http://localhost");
+  const pathname = decodeURIComponent(url.pathname);
+  const requestedPath = pathname === "/" ? "/index.html" : pathname;
+  const absolutePath = path.resolve(repoRoot, `.${requestedPath}`);
+  const withinRepo =
+    absolutePath === repoRoot || absolutePath.startsWith(`${repoRoot}${path.sep}`);
+
+  if (!withinRepo) {
+    return null;
+  }
+
+  if (fs.existsSync(absolutePath) && fs.statSync(absolutePath).isDirectory()) {
+    return path.join(absolutePath, "index.html");
+  }
+
+  return absolutePath;
+}
+
+function sendFile(response, filePath) {
+  const stream = fs.createReadStream(filePath);
+
+  response.writeHead(200, {
+    "Content-Type": getContentType(filePath),
+    "Cache-Control": "no-cache",
+  });
+
+  stream.pipe(response);
+  stream.on("error", () => {
+    response.writeHead(500, { "Content-Type": "text/plain; charset=utf-8" });
+    response.end("Failed to read file");
+  });
+}
+
+function createServer() {
+  return http.createServer((request, response) => {
+    const filePath = resolveRequestPath(request.url || "/");
+
+    if (!filePath) {
+      response.writeHead(403, { "Content-Type": "text/plain; charset=utf-8" });
+      response.end("Forbidden");
+      return;
+    }
+
+    if (!fs.existsSync(filePath) || !fs.statSync(filePath).isFile()) {
+      response.writeHead(404, { "Content-Type": "text/plain; charset=utf-8" });
+      response.end("Not found");
+      return;
+    }
+
+    sendFile(response, filePath);
+  });
+}
+
+function main() {
+  const options = parseArgs(process.argv.slice(2));
+  const server = createServer();
+
+  server.listen(options.port, options.host, () => {
+    console.log(`Serving ${repoRoot} at http://${options.host}:${options.port}`);
+  });
+}
+
+if (require.main === module) {
+  try {
+    main();
+  } catch (error) {
+    console.error(error.message);
+    process.exitCode = 1;
+  }
+}