recurse db server

main.ts

const DB: Record<string, string> = {};

Deno.serve({ port: 4000 }, (req: Request) => {
  const reqUrl = new URL(req.url);
  switch (reqUrl.pathname) {
    case "/get": {
      try {
        const key = parseGetParams(reqUrl.searchParams);
        if (Object.keys(DB).includes(key)) return res(200, DB[key]);
        return res(404, { error: `DB key "${key}" not found in db.` });
      } catch (e: unknown) {
        const error = e instanceof Error ? e.message : "Unknown error";
        return res(400, { error });
      }
    }

    case "/set": {
      const keys = [...reqUrl.searchParams.keys()];
      for (const key of keys) {
        DB[key] = reqUrl.searchParams.get(key) ?? "null";
      }
      return res(200, { status: "OK" });
    }
    default:
      return res(200, DB);
  }
});

const parseGetParams = (params: URLSearchParams) => {
  const validParamKey = "key";
  const submittedKeys = new Set([...params.keys()]);

  if (!submittedKeys.has(validParamKey)) {
    throw new Error(`Expected param with key of "key", but instead received "${Array.from(submittedKeys)}".`);
  }

  const key = params.get(validParamKey);

  if (key === null) {
    throw new Error(`Value was null. Please submit a valid value.`);
  }

  return key;
};

const res = (status: number, body: Record<string, string> | string) =>
  new Response(JSON.stringify(body) ?? "{}", { status, headers: { "content-type": "text/json" } });