What causes "Invalid cycle: ${cycle}" in DIYgod/RSSHub?

Use `date`, `week`, or `month` — or omit the parameter entirely (defaults to `date`).

DIYgod/RSSHub · warning · Error

Invalid cycle: ${cycle}

Error message

Invalid cycle: ${cycle}

What it means

Thrown by the Hugging Face Daily Papers route when the `:cycle` path parameter is not one of `date`, `week`, or `month`. The handler uses a `switch` statement with a `default` branch that throws a plain `Error` (not `InvalidParameterError`, which is inconsistent with RSSHub conventions). The cycle determines which Hugging Face papers URL is fetched.

Source

Thrown at lib/routes/huggingface/daily-papers.ts:64

    dailyPapers: DailyPaperItem[];
}

async function handler(ctx) {
    const { cycle = 'date', voteFliter = '0' } = ctx.req.param();
    let url: string;
    switch (cycle) {
        case 'date':
            url = 'https://huggingface.co/papers';
            break;
        case 'week':
            // We don't actually need to get the week number, because huggingface.co/papers/week/YYYY-W52 will redirect to the latest week
            url = `https://huggingface.co/papers/week/${new Date().getFullYear()}-W52`;
            break;
        case 'month':
            url = `https://huggingface.co/papers/month/${new Date().toISOString().slice(0, 7)}`;
            break;
        default:
            throw new Error(`Invalid cycle: ${cycle}`);
    }

    const { body: response } = await got(url);
    const $ = load(response);
    const papers = $('div[data-target="DailyPapers"]').data('props') as PapersData;

    const items = papers.dailyPapers
        .filter((item) => item.paper.upvotes >= voteFliter)
        .map((item) => ({
            title: item.title,
            link: `https://arxiv.org/abs/${item.paper.id}`,
            description: item.paper.summary.replaceAll('\n', ' '),
            pubDate: parseDate(item.publishedAt),
            author: item.paper.authors.map((author) => author.name).join(', '),
            upvotes: item.paper.upvotes,
        }))
        .toSorted((a, b) => b.upvotes - a.upvotes);

View on GitHub (pinned to bed535e087)

Solutions

Use `date`, `week`, or `month` — or omit the parameter entirely (defaults to `date`).
As a maintainer: change `throw new Error(...)` to `throw new InvalidParameterError(...)` for consistent HTTP 400 behavior.

Example fix

// before (broken)
// GET /huggingface/daily-papers/yearly/50

// after (correct)
// GET /huggingface/daily-papers/week/50

Defensive patterns

Strategy: validation

Validate before calling

const VALID_CYCLES = ['date', 'week', 'month'] as const;
function isValidCycle(cycle: string): cycle is typeof VALID_CYCLES[number] {
    return (VALID_CYCLES as readonly string[]).includes(cycle);
}

Type guard

function isValidPapersCycle(cycle: string): cycle is 'date' | 'week' | 'month' {
    return ['date', 'week', 'month'].includes(cycle);
}

Prevention

Use `InvalidParameterError` instead of plain `Error` for consistent HTTP 400 behavior.
Omit the cycle parameter to default to `date`.
Document the three valid values in the route parameters description.

When it happens

Trigger: Requesting `/huggingface/daily-papers/<cycle>/...` where `<cycle>` is not `date`, `week`, or `month`. The parameter defaults to `date` when omitted, so omitting it is safe.

Common situations: Typo in the cycle value, using an unsupported value like `year` or `daily`, or passing an empty string explicitly.

Related errors

AI-assisted analysis of DIYgod/RSSHub@bed535e087 (2026-08-12). Data as JSON: /api/errors/81d429526909526f. Report an issue: GitHub.