---
title: 'DirectoryExpander'
---

Expands directories created by [`ctx.actions.declare_directory`](/versions/9.1.0/rules/lib/builtins/actions#declare_directory) during the execution phase. This is useful to expand directories in [`map_each`](/versions/9.1.0/rules/lib/builtins/Args#add_all.map_each).

## Members

* [expand](#expand)

## expand

```
list DirectoryExpander.expand(file)
```

If the given `File` is a directory, this returns a list of `File`s recursively underneath the directory. Otherwise, this returns a list containing just the given `File` itself.

### Parameters

| Parameter | Description |
| --- | --- |
| `file` | [File](/versions/9.1.0/rules/lib/builtins/File); required  The directory or file to expand. |