linguist-js/dist/analyser/classifiers/byExtension.js

Analyse the programming languages used in a folder or from raw content, using the same rules that GitHub Linguist does.

import { getFileExtension } from '../../program/fs/normalisedPath.js';
function isComplexExt(ext) {
    return /\..+\./.test(ext);
}
export default function byExtension(file, langData) {
    // Check if extension is a match
    const extension = file.extension ?? getFileExtension(file.path);
    if (!extension)
        return [];
    const possible = [];
    for (const [lang, data] of Object.entries(langData)) {
        const extMatches = data.extensions?.filter((ext) => file.path.toLowerCase().endsWith(ext.toLowerCase()));
        if (extMatches?.length) {
            for (const ext of extMatches) {
                possible.push({ ext, lang });
            }
        }
    }
    // Apply more specific extension if available
    const hasComplexExt = possible.some((entry) => isComplexExt(entry.ext));
    return possible
        .filter((entry) => {
        const complex = isComplexExt(entry.ext);
        if (hasComplexExt && !complex)
            return false;
        if (!hasComplexExt && complex)
            return false;
        return true;
    })
        .map((entry) => entry.lang);
}