Add chpi to known channel list

doc/whats_new.rst

@@ -20,6 +20,7 @@ The following authors contributed for the first time. Thank you so much! 🤩
 * `Aaron Earle-Richardson`_
 * `Amaia Benitez`_
 * `Kaare Mikkelsen`_
+* `Simon Kern`_
 * `Thomas Hartmann`_
 * `William Turner`_
 
@@ -55,6 +56,7 @@ Detailed list of changes
 🪲 Bug fixes
 ^^^^^^^^^^^^
 
+- Writing MEGIN data with MNE channel types `chpi` will now map to BIDS type HLU by `Simon Kern`_ (:gh:`1325`)
 - When anonymizing the date of a recording, MNE-BIDS will no longer error during `~mne_bids.write_raw_bids` if passing a `~mne.io.Raw` instance to ``empty_room``, by `Daniel McCloy`_ (:gh:`1270`)
 - Dealing with alphanumeric ``sub`` entity labels is now fixed for :func:`~mne_bids.write_raw_bids`, by `Aaron Earle-Richardson`_ (:gh:`1291`)
 - When processing subject_info data that MNE Python imports as numpy arrays with only one item, MNE-BIDS now unpacks these, resulting in a correct participants.tsv, by `Thomas Hartmann`_ (:gh:`1310`)

mne_bids/tests/test_utils.py

@@ -39,6 +39,36 @@ def test_get_ch_type_mapping():
     with pytest.raises(ValueError, match='specified from "bogus" to "mne"'):
         _get_ch_type_mapping(fro="bogus", to="mne")
 
+    # check that all mne types have a corresponding BIDS translation
+    # last update from mne 0.19.0.
+    mne_valid_types = [
+        "bio",
+        "chpi",
+        "dbs",
+        # "dipole",  # currently not converted
+        "ecg",
+        "ecog",
+        "eeg",
+        "emg",
+        "eog",
+        "exci",
+        # "eyetrack",  # currently not converted
+        # "fnirs",  # currently not converted
+        # "gof",  # currently not converted
+        "gsr",
+        "ias",
+        "misc",
+        # "meg",  # inferred in more detail
+        "resp",
+        "seeg",
+        "stim",
+        "syst",
+        "temperature",
+    ]
+    map_mne_to_bids = _get_ch_type_mapping(fro="mne", to="bids")
+    for ch_type in mne_valid_types:
+        assert ch_type in map_mne_to_bids
+
 
 def test_handle_datatype():
     """Test the automatic extraction of datatype from the data."""

mne_bids/utils.py

@@ -82,6 +82,7 @@ def _get_ch_type_mapping(fro="mne", to="bids"):
             megrefgradaxial="MEGREFGRADAXIAL",
             meggradplanar="MEGGRADPLANAR",
             megrefmag="MEGREFMAG",
+            chpi="HLU",
             ias="MEGOTHER",
             syst="MEGOTHER",
             exci="MEGOTHER",