What causes "Invalid language" in DIYgod/RSSHub?

Use a supported two-letter code (en, de, es, fr, ja, zh, etc.) or omit the parameter for English.

DIYgod/RSSHub · warning · InvalidParameterError

Invalid language

Error message

Invalid language

What it means

Thrown by the MyFigureCollection main (pictures) route when the :language parameter is non-empty and fails the same isValidHost regex used in the activity route. The language becomes a subdomain of myfigurecollection.net, so it must be a syntactically valid DNS label. This is the identical guard to error 758 but on the sibling route.

Source

Thrown at lib/routes/myfigurecollection/index.tsx:47

    radar: [
        {
            source: ['zh.myfigurecollection.net/browse', 'zh.myfigurecollection.net/'],
        },
    ],
    name: '圖片',
    maintainers: ['nczitzk'],
    handler,
    url: 'zh.myfigurecollection.net/browse',
    description: `| 每日圖片 | 每週圖片 | 每月圖片 |
| -------- | -------- | -------- |
| potd     | potw     | potm     |`,
};

async function handler(ctx) {
    const language = ctx.req.param('language') ?? '';
    const category = ctx.req.param('category') ?? 'figure';
    if (language && !isValidHost(language)) {
        throw new InvalidParameterError('Invalid language');
    }

    const rootUrl = `https://${language === 'en' || language === '' ? '' : `${language}.`}myfigurecollection.net`;
    const currentUrl = `${rootUrl}/${Object.hasOwn(shortcuts, category) ? shortcuts[category] : category}`;

    const response = await got({
        method: 'get',
        url: currentUrl,
    });

    const $ = load(response.data);

    let items = $('.item-icon, .picture-icon')
        .slice(0, ctx.req.query('limit') ? Number.parseInt(ctx.req.query('limit')) : 25)
        .toArray()
        .map((item): DataItem => {
            const $item = $(item).find('a');

View on GitHub (pinned to bed535e087)

Solutions

Use a supported two-letter code (en, de, es, fr, ja, zh, etc.) or omit the parameter for English.
Share a single allowed-language constant between this route and the activity route to keep them in sync.
Add a DNS-resolution or HTTP-probe fallback if you want to support unknown-but-valid subdomains.

Example fix

// before
if (language && !isValidHost(language)) {
    throw new InvalidParameterError('Invalid language');
}

// after — shared allowlist with the activity route
import { MFC_LANGUAGES } from './languages';
if (language && !MFC_LANGUAGES.includes(language.toLowerCase())) {
    throw new InvalidParameterError(`Invalid language '${language}'. Supported: ${MFC_LANGUAGES.join(', ')}`);
}

Defensive patterns

Strategy: validation

Validate before calling

// Share a constant with the activity route
import { MFC_LANGUAGES } from './languages';
const language = (ctx.req.param('language') ?? '').toLowerCase();
if (language && !MFC_LANGUAGES.includes(language)) {
    throw new InvalidParameterError(`Invalid language '${language}'. Supported: ${MFC_LANGUAGES.filter(Boolean).join(', ')}`);
}

Type guard

function isMfcLanguage(l: string): boolean {
    const allowed = new Set(['', 'en', 'de', 'es', 'fi', 'fr', 'it', 'ja', 'nl', 'no', 'pl', 'pt', 'ru', 'sv', 'zh']);
    return allowed.has(l.toLowerCase());
}

Prevention

Extract the valid-language list into a shared module so both MFC routes stay in sync.
Prefer an explicit allowlist over the hostname regex for clearer errors.
Normalize case before checking.
Document that an empty language segment means English (the default).

When it happens

Trigger: Same as 758: a language value containing dots, underscores, spaces, non-ASCII, or exceeding 63 characters. The default (empty string → en) never triggers this; only an explicitly-supplied invalid value does.

Common situations: User passes an IETF-style tag like 'zh-Hant' (hyphenated is allowed by the regex but may not resolve as a real subdomain). User passes a full URL or hostname fragment. User passes a numeric-only code that happens to pass the regex but isn't a real MFC subdomain.

Related errors

AI-assisted analysis of DIYgod/RSSHub@bed535e087 (2026-08-12). Data as JSON: /api/errors/b4173d79b77c26b8. Report an issue: GitHub.