FileSystem#deleteRecursively(path)

[vanniktech]

okio's FileSystem has deleteRecursively which is handy when deleting a directory. This is missing in the kotlinx io FileSystem.

[westnordost]

So, something like this.

/**
 * Delete the given path, recursively if it is a directory.
 *
 * @throws kotlinx.io.files.FileNotFoundException - when [path] does not exist and [mustExist] is
 *         `true`
 * @throws kotlinx.io.IOException if there was an underlying error preventing listing the [path]'s
 *         children if it was a directory
 * */
fun FileSystem.deleteRecursively(path: Path, mustExist: Boolean = true) {
    val isDirectory = metadataOrNull(path)?.isDirectory ?: false
    if (isDirectory) {
        for (child in list(path)) {
            deleteRecursively(child, mustExist)
        }
    }
    delete(path, mustExist)
}

Though, I think generally it would be more useful to have an interface similar to kotlin.io.FileTreeWalk, i.e. have a Sequence of Path returned. Because with this kind of interface, a broader range of use cases would be covered. With that interface, a (recursive) delete of files could look like this

FileSystem.walkBottomUp(path).forEach { FileSystem.delete(it) }

which would be super-straightforward.