next.js/packages/next/src/shared/lib/page-path/normalize-path-sep.ts

/**
 * For a given page path, this function ensures that there is no backslash
 * escaping slashes in the path. Example:
 *  - `foo\/bar\/baz` -> `foo/bar/baz`
 */
export function normalizePathSep(path: string): string {
  return path.replace(/\\/g, '/')
}