MRG: Make print_dir_tree expand ~ (#1013)

* Make print_dir_tree expand ~

* Fix test and add changelog entry

doc/whats_new.rst

@@ -52,6 +52,8 @@ Detailed list of changes
 
 - The deprecated function ``mne_bids.mark_bad_channels`` has been removed in favor of :func:`mne_bids.mark_channels`, by `Richard Höchenberger`_ (:gh:`1009`)
 
+- :func:`mne_bids.print_dir_tree` now raises a :py:class:`FileNotFoundError` instead of a :py:class:`ValueError` if the directory does not exist, by `Richard Höchenberger`_ (:gh:`1013`)
+
 🛠 Requirements
 ^^^^^^^^^^^^^^^
 
@@ -68,6 +70,8 @@ Detailed list of changes
 
 - :func:`~mne_bids.copyfiles.copyfile_brainvision` can now deal with ``.dat`` file extension, by `Dominik Welke`_ (:gh:`1008`)
 
+- :func:`~mne_bids.print_dir_tree` now correctly expands ``~`` to the user's home directory, by `Richard Höchenberger`_ (:gh:`1013`)
+
 :doc:`Find out what was new in previous releases <whats_new_previous_releases>`
 
 .. include:: authors.rst

mne_bids/path.py

@@ -1174,9 +1174,13 @@ def print_dir_tree(folder, max_depth=None, return_str=False):
         If `return_str` is ``True``, the directory tree is returned as a
         string. Else, ``None`` is returned and the directory tree is printed.
     """
-    if not op.exists(folder):
-        raise ValueError('Directory does not exist: {}'.format(folder))
-
+    folder = _check_fname(
+        fname=folder,
+        overwrite='read',
+        must_exist=True,
+        name='Folder',
+        need_dir=True
+    )
     max_depth = _check_max_depth(max_depth)
 
     _validate_type(return_str, bool, 'return_str')

mne_bids/tests/test_path.py

@@ -165,7 +165,7 @@ def test_search_folder_for_text(capsys):
 
 def test_print_dir_tree(capsys):
     """Test printing a dir tree."""
-    with pytest.raises(ValueError, match='Directory does not exist'):
+    with pytest.raises(FileNotFoundError, match='Folder does not exist'):
         print_dir_tree('i_dont_exist')
 
     # We check the testing directory