jackwener/OpenCLI · error · ArgumentError

--${name} is required

Error message

--${name} is required

What it means

This ArgumentError from requireString is thrown when a required CLI argument is missing, not a string, or an empty/whitespace-only string. It fails fast before any network call, and the message names the flag (prefixed with --) that must be supplied.

Source

Thrown at clis/wttr/utils.js:13

// wttr.in shared helpers — global weather (no auth, terminal-friendly JSON via ?format=j1).
//
// Coverage: worldwide. Unlike NWS (US-only), wttr.in geocodes any city/airport
// code/lat,lon string and serves a 3-day forecast + current conditions in one
// payload.
import { ArgumentError, EmptyResultError, CommandExecutionError } from '@jackwener/opencli/errors';

export const WTTR_BASE = 'https://wttr.in';
const UA = 'opencli-wttr/1.0';

export function requireString(value, name) {
    if (typeof value !== 'string' || !value.trim()) {
        throw new ArgumentError(`--${name} is required`);
    }
    return value.trim();
}

export async function wttrFetch(location, label) {
    // wttr.in path-encodes the location. Spaces → %20 is fine; commas survive.
    const url = `${WTTR_BASE}/${encodeURIComponent(location)}?format=j1`;
    let resp;
    try {
        resp = await fetch(url, { headers: { 'User-Agent': UA, accept: 'application/json' } });
    } catch (err) {
        throw new CommandExecutionError(`${label} request failed: ${err.message}`);
    }
    if (resp.status === 404) {
        throw new EmptyResultError(label, `${label} could not find location "${location}".`);
    }
    if (!resp.ok) {
        throw new CommandExecutionError(`${label} returned HTTP ${resp.status}.`);

View on GitHub (pinned to 49907e53dc)

Solutions

1. Pass a non-empty location, e.g. --location 'New York'
2. Check that the variable feeding the argument is defined and non-blank
3. Trim or validate user input before passing it

Example fix

// before
await query({ location: process.env.CITY }); // CITY unset -> undefined
// after
const city = process.env.CITY?.trim();
if (!city) throw new Error('Set CITY env var');
await query({ location: city });

function requireString(value, name) {
  if (typeof value !== 'string' || !value.trim()) {
    throw new Error(`--${name} is required`);
  }
  return value.trim();
}
const location = requireString(args.location, 'location');

function isNonEmptyString(v) {
  return typeof v === 'string' && v.trim().length > 0;
}

try {
  result = await query({ location: args.location });
} catch (err) {
  if (err instanceof ArgumentError && err.message.includes('is required')) {
    console.error('Usage: --location <city|lat,lon>');
  } else throw err;
}

When it happens

Trigger: Calling query (or any requireString caller) without args.location, with location: undefined/null, or with location: '' or ' '.

Common situations: Forgetting the --location flag on the command line; a script variable that is undefined because an env var was unset; empty string after shell quoting mistakes.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• keyword must not be empty
• <from> station must not be empty
• <to> station must not be empty
• who 不能为空
• key is required

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/9e559520b3a98f43. Report an issue: GitHub.