next.js/packages/next/src/lib/format-dynamic-import-path.ts

import path from 'path'
import { pathToFileURL } from 'url'

/**
 * The path for a dynamic route must be URLs with a valid scheme.
 *
 * When an absolute Windows path is passed to it, it interprets the beginning of the path as a protocol (`C:`).
 * Therefore, it is important to always construct a complete path.
 * @param dir File directory
 * @param filePath Absolute or relative path
 */
export const formatDynamicImportPath = (dir: string, filePath: string) => {
  const absoluteFilePath = path.isAbsolute(filePath)
    ? filePath
    : path.join(dir, filePath)
  const formattedFilePath = pathToFileURL(absoluteFilePath).toString()

  return formattedFilePath
}