jackwener/OpenCLI · error · ArgumentError

oeis sequence id is required (e.g. "A000045" for Fibonacci)

Error message

oeis sequence id is required (e.g. "A000045" for Fibonacci)

What it means

requireSequenceId converts its argument to a trimmed, uppercased string and throws this ArgumentError when the result is empty. Every OEIS lookup needs an A-number (like A000045), so an absent id cannot proceed. The function also tolerates pasted OEIS URLs before validating the format.

Source

Thrown at clis/oeis/utils.js:34

    if (!s) throw new ArgumentError(`oeis ${label} cannot be empty`);
    return s;
}

export function requireBoundedInt(value, defaultValue, maxValue, label = 'limit') {
    const raw = value ?? defaultValue;
    const n = typeof raw === 'number' ? raw : Number(raw);
    if (!Number.isInteger(n) || n <= 0) {
        throw new ArgumentError(`oeis ${label} must be a positive integer`);
    }
    if (n > maxValue) {
        throw new ArgumentError(`oeis ${label} must be <= ${maxValue}`);
    }
    return n;
}

export function requireSequenceId(value) {
    const raw = String(value ?? '').trim().toUpperCase();
    if (!raw) throw new ArgumentError('oeis sequence id is required (e.g. "A000045" for Fibonacci)');
    // Tolerate common URL paste like `https://oeis.org/A000045`.
    const stripped = raw.replace(/^HTTPS?:\/\/(?:WWW\.)?OEIS\.ORG\//, '').replace(/\/.*$/, '');
    if (!SEQUENCE_ID_PATTERN.test(stripped)) {
        throw new ArgumentError(
            `oeis sequence id "${value}" is not a valid A-number`,
            'Expected format: "A" + digits (e.g. "A000045").',
        );
    }
    return stripped;
}

export async function oeisFetch(url, label) {
    let resp;
    try {
        resp = await fetch(url, { headers: { 'user-agent': UA, accept: 'application/json' } });
    }
    catch (err) {
        throw new CommandExecutionError(

View on GitHub (pinned to 49907e53dc)

Solutions

1. Provide a sequence id, e.g. `oeis id A000045`.
2. Check that the variable holding the id is actually set and non-empty.
3. Use the full OEIS URL if easier — it is accepted and parsed (e.g. https://oeis.org/A000045).

Example fix

// before
oeis id "$SEQ"   # SEQ is empty
// after
oeis id A000045

if (!id || !String(id).trim()) throw new Error('A sequence id is required, e.g. A000045');

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

try { const sid = requireSequenceId(opts.id); } catch (e) { console.error(e.message); process.exitCode = 1; }

When it happens

Trigger: Calling the `id` command/path with no argument, an empty string, or a value that is only whitespace (e.g. requireSequenceId(' ') or `oeis id ""`).

Common situations: Forgetting the positional argument on the command line, or a shell variable like $SEQ being unset so the script passes an empty value.

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

• archive search sort must be one of ${SORT_OPTIONS.join(', ')
• archive search mediatype must be one of ${MEDIATYPES.join(',
• archive search limit must be a positive integer
• archive search query must not be empty
• arxiv author cannot be empty

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/fecb1dbcb9c07413. Report an issue: GitHub.