get-freq.ts

import { cli, Command, Flags } from "https://deno.land/x/cobra@v0.0.9/mod.ts";
import {
  connect,
  Empty,
  ErrorCode,
  JSONCodec,
  NatsConnection,
  ServiceErrorHeader,
} from "./natslib.ts";

const root = cli({
  use: "get-freq ",
  run: async (
    cmd: Command,
    _args: string[],
    flags: Flags,
  ): Promise<number> => {
    const nc = await createConnection(flags);
    return nc.request(
      "badge.freq",
      Empty,
      { timeout: 30 * 1000 },
    ).then((msg) => {
      if (msg.headers?.get(ServiceErrorHeader)) {
        cmd.stdout(
          `error processing your request: ${
            msg.headers.get(ServiceErrorHeader)
          }`,
        );
        return 1;
      }
      const jc = JSONCodec();
      const m = jc.decode(msg.data);
      if (Object.keys(m).length) {
        console.table(m);
      } else {
        cmd.stdout("no badge generation requests seen");
      }
      return 0;
    }).catch((err) => {
      if (err.code === ErrorCode.NoResponders) {
        cmd.stdout(`sorry no frequency-service services were found`);
      } else {
        cmd.stdout(`error: ${err.message}`);
      }
      return 1;
    });
  },
});

root.addFlag({
  name: "server",
  type: "string",
  usage: "NATS server to connect to",
  default: "demo.nats.io",
  persistent: true,
});

function createConnection(flags: Flags): Promise<NatsConnection> {
  const servers = [flags.value<string>("server")];
  return connect({ servers });
}

Deno.exit(await root.execute(Deno.args));