Function getSafeFilePath

packages/components/src/validator.ts:444–473

(baseDir: string, key: string)

 * @throws {Error} If key is missing/invalid or the resolved path escapes baseDir
 */
export const getSafeFilePath = (baseDir: string, key: string): string => {
    if (!key || typeof key !== 'string') {
        throw new Error('Invalid file path: key is required and must be a string')
    }

    let decodedKey = key
    try {
        decodedKey = decodeURIComponent(key)
    } catch {
        // malformed percent-encoding — keep the raw key; resolve/relative handle it safely
    }

    if (decodedKey.includes('\0')) {
        throw new Error(`Invalid file path: null byte detected in "${key}"`)
    }

    const resolvedBase = path.resolve(baseDir)
    const resolvedPath = path.resolve(resolvedBase, decodedKey)

    if (process.env.PATH_TRAVERSAL_SAFETY === 'false') {
        return resolvedPath
    }

    const relative = path.relative(resolvedBase, resolvedPath)
    if (relative === '' || relative === '..' || relative.startsWith('..' + path.sep) || path.isAbsolute(relative)) {
        throw new Error(`Invalid file path: path traversal attempt detected in "${key}"`)
    }

    return resolvedPath
}