diff --git a/.github/workflows/unit_tests.yml b/.github/workflows/unit_tests.yml
index c2532dacb..3b1a084ef 100644
--- a/.github/workflows/unit_tests.yml
+++ b/.github/workflows/unit_tests.yml
@@ -176,7 +176,14 @@ jobs:
       run: |
         export BIDS_VALIDATOR_VERSION=`bids-validator --version`
         echo Using bids-validator $BIDS_VALIDATOR_VERSION
-        python -m pytest . --cov=mne_bids mne_bids/tests/ mne_bids/commands/tests/ --cov-report=xml --cov-config=setup.cfg --verbose --ignore mne-python
+        python -m pytest . \
+        --doctest-modules \
+        --cov=mne_bids mne_bids/tests/ mne_bids/commands/tests/ \
+        --cov-report=xml \
+        --cov-config=setup.cfg \
+        --verbose \
+        --ignore mne-python \
+        --ignore examples
       shell: bash
     - name: Upload coverage stats to codecov
       if: ${{ matrix.os == 'ubuntu-latest' && matrix.python-version == '3.9' && matrix.bids-validator == 'main' }}
diff --git a/doc/whats_new.rst b/doc/whats_new.rst
index 1b2f1e6a1..8ce6f95f6 100644
--- a/doc/whats_new.rst
+++ b/doc/whats_new.rst
@@ -26,14 +26,20 @@ Authors
 * `Alex Rockhill`_
 * `Richard Höchenberger`_
 * `Adam Li`_
+* `Eduard Ort`_
 * `Richard Köhler`_ (new contributor)
 * `Jean-Rémi King`_ (new contributor)
+* `Sin Kim`_ (new contributor)
+* `Alexandre Gramfort`_
+* `Mainak Jas`_
+* `Stefan Appelhoff`_
 
 Detailed list of changes
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
 Enhancements
 ^^^^^^^^^^^^
+
 - The fields "DigitizedLandmarks" and "DigitizedHeadPoints" in the json sidecar of Neuromag data are now set to True/False depending on whether any landmarks (NAS, RPA, LPA) or extra points are found in raw.info['dig'], by `Eduard Ort`_ (:gh:`772`)
 - Updated the "Read BIDS datasets" example to use data from `OpenNeuro <https://openneuro.org>`_, by `Alex Rockhill`_ (:gh:`753`)
 - :func:`mne_bids.get_head_mri_trans` is now more lenient when looking for the fiducial points (LPA, RPA, and nasion) in the MRI JSON sidecar file, and accepts a larger variety of landmark names (upper- and lowercase letters; ``'nasion'`` instead of only ``'NAS'``), by `Richard Höchenberger`_ (:gh:`769`)
@@ -56,8 +62,9 @@ API and behavior changes
 - The ``raw_to_bids`` command has lost its ``--allow_maxshield`` parameter. If writing a FIFF file, we will now always assume that writing data before applying a Maxwell filter is fine, by `Richard Höchenberger`_ (:gh:`787`)
 - :meth:`mne_bids.BIDSPath.find_empty_room` now first looks for an ``AssociatedEmptyRoom`` field in the MEG JSON sidecar file to retrieve the empty-room recording; only if this information is missing, it will proceed to try and find the best-matching empty-room recording based on measurement date (i.e., fall back to the previous behavior), by `Richard Höchenberger`_ (:gh:`795`)
 - If :func:`mne_bids.read_raw_bids` encounters raw data with the ``STI 014`` stimulus channel and this channel is not explicitly listed in ``*_channels.tsv``, it is now automatically removed upon reading, by `Richard Höchenberger`_ (:gh:`823`)
-- :func:`mne_bids.get_anat_landmarks` was added to clarify and simplify the process of generating landmarks that now need to be passed to :func:`mne_bids.write_anat`; this depreciates the arguments ``raw``, ``trans`` and ``t1w`` of :func:`mne_bids.write_anat`, by `Alex Rockhill`_ and `Alexandre Gramfort`_ (:gh:`827`)
-- :func:`write_raw_bids` now accepts preloaded raws as input with some caveats if the new parameter ``allow_preload`` is explicitly set to ``True``. This enables some preliminary support for uncommon file formats, generated data, processed derivatives etc., by `Sin Kim`_ (:gh:`819`)
+- :func:`mne_bids.get_anat_landmarks` was added to clarify and simplify the process of generating landmarks that now need to be passed to :func:`mne_bids.write_anat`; this deprecates the arguments ``raw``, ``trans`` and ``t1w`` of :func:`mne_bids.write_anat`, by `Alex Rockhill`_ and `Alexandre Gramfort`_ (:gh:`827`)
+- :func:`write_raw_bids` now accepts preloaded raws as input with some caveats if the new parameter ``allow_preload`` is explicitly set to ``True``. This enables some preliminary support for items such as uncommon file formats, generated data, and processed derivatives, by `Sin Kim`_ (:gh:`819`)
+- MNE-BIDS now writes all TSV data files with a newline character at the end of the file, complying with UNIX/POSIX standards, by `Stefan Appelhoff`_ (:gh:`831`)
 
 Requirements
 ^^^^^^^^^^^^
diff --git a/examples/bidspath.py b/examples/bidspath.py
index dfd48d05f..86ad98d6b 100644
--- a/examples/bidspath.py
+++ b/examples/bidspath.py
@@ -14,6 +14,9 @@
 # %%
 # Obviously, to start exploring BIDSPath, we first need to import it.
 
+from pathlib import Path
+
+import mne_bids
 from mne_bids import BIDSPath
 
 # %%
@@ -27,13 +30,15 @@
 # consider where to store your data upon BIDS conversion. Again, the intended
 # target folder will be the BIDS root of your data.
 #
-# Let's just pick an arbitrary BIDS root, for the purpose of this
-# demonstration.
+# For the purpose of this demonstration, let's pick the ``tiny_bids`` example
+# dataset that ships with the MNE-BIDS test suite.
 
-bids_root = './my_bids_root'
+# We are using a pathlib.Path object for convenience, but you could just use
+# a string to specify ``bids_root`` here.
+bids_root = Path(mne_bids.__file__).parent / 'tests' / 'data' / 'tiny_bids'
 
 # %%
-# This refers to a folder named `my_bids_root` in the current working
+# This refers to a folder named ``my_bids_root`` in the current working
 # directory. Finally, let is create a ``BIDSPath``, and tell it about our
 # BIDS root. We can then also query the ``BIDSPath`` for its root.
 
@@ -45,7 +50,7 @@
 # identifiers**. We can either create a new ``BIDSPath``, or update our
 # existing one. The value can be retrieved via the ``.subject`` attribute.
 
-subject = '123'
+subject = '01'
 
 # Option 1: Create an entirely new BIDSPath.
 bids_path_new = BIDSPath(subject=subject, root=bids_root)
@@ -66,7 +71,7 @@
 # information on our experimental session, and try to retrieve it again via
 # ``.session``.
 
-session = 'test'
+session = 'eeg'
 bids_path.update(session=session)
 print(bids_path.session)
 
@@ -78,7 +83,7 @@
 # using `mne_bids.write_raw_bids`. For the sake of this example, however, we
 # are going to specify the data type explicitly.
 
-datatype = 'meg'
+datatype = 'eeg'
 bids_path.update(datatype=datatype)
 print(bids_path.datatype)
 
@@ -110,7 +115,7 @@
 # %%
 # The two entities you can see here are the ``subject`` entity (``sub``) and
 # the ``session`` entity (``ses``). Each entity name also has a value; for
-# ``sub``, this is ``123``, and for ``ses``, it is ``test`` in our example.
+# ``sub``, this is ``01``, and for ``ses``, it is ``eeg`` in our example.
 # Entity names (or "keys") and values are separated via hyphens.
 # BIDS knows a much larger number of entities, and MNE-BIDS allows you to make
 # use of them. To get a list of all supported entities, use:
@@ -129,11 +134,25 @@
 
 # %%
 # As you can see, the ``basename`` has been updated. In fact, the entire
-# **path** has been updated, and the ``ses-test`` folder has been dropped from
+# **path** has been updated, and the ``ses-eeg`` folder has been dropped from
 # the path:
 
 print(bids_path.fpath)
 
+# %%
+# Oups! The cell above produced a ``RuntimeWarning`` that our data file could
+# not be found. That's because we changed the ``run`` and ``session`` entities
+# above, and the ``tiny_bids`` dataset does not contain corresponding data.
+#
+# That shows us that ``BIDSPath`` is doing a lot of guess-work and checking
+# in the background, but note that this may change in the future.
+#
+# For now, let's revert to the last working iteration of our ``bids_path``
+# instance.
+
+bids_path.update(run=None, session='eeg')
+print(bids_path.fpath)
+
 # %%
 # Awesome! We're almost done! Two important things are still missing, though:
 # the so-called **suffix** and the filename **extension**. Sometimes these
@@ -151,7 +170,7 @@
 # ``.tsv``.
 # Let's put our new knowledge to use!
 
-bids_path.update(suffix='meg', extension='fif')
+bids_path.update(suffix='eeg', extension='.vhdr')
 print(bids_path.fpath)
 bids_path
 
diff --git a/mne_bids/inspect.py b/mne_bids/inspect.py
index e9533e1d1..8d8a3826a 100644
--- a/mne_bids/inspect.py
+++ b/mne_bids/inspect.py
@@ -1,3 +1,9 @@
+"""Inspect and annotate BIDS raw data."""
+# Authors: Richard Höchenberger <richard.hoechenberger@gmail.com>
+#          Stefan Appelhoff <stefan.appelhoff@mailbox.org>
+#
+# License: BSD (3-clause)
+
 from pathlib import Path
 
 import numpy as np
@@ -78,8 +84,12 @@ def inspect_dataset(bids_path, find_flat=True, l_freq=None, h_freq=None,
     Disable flat channel & segment detection, and apply a filter with a
     passband of 1–30 Hz.
 
-    >>> inspect_dataset(bids_path=bids_path, find_flat=False,
-                        l_freq=1, h_freq=30)
+    >>> from mne_bids import BIDSPath
+    >>> root = Path('./mne_bids/tests/data/tiny_bids').absolute()
+    >>> bids_path = BIDSPath(subject='01', task='rest', session='eeg',
+    ...                      suffix='eeg', extension='.vhdr', root=root)
+    >>> inspect_dataset(bids_path=bids_path, find_flat=False,  # doctest: +SKIP
+    ...                 l_freq=1, h_freq=30)
     """
     allowed_extensions = set(ALLOWED_DATATYPE_EXTENSIONS['meg'] +
                              ALLOWED_DATATYPE_EXTENSIONS['eeg'] +
diff --git a/mne_bids/path.py b/mne_bids/path.py
index bceba12d0..e8ea9a872 100644
--- a/mne_bids/path.py
+++ b/mne_bids/path.py
@@ -1,5 +1,6 @@
 """BIDS compatible path functionality."""
 # Authors: Adam Li <adam2392@gmail.com>
+#          Stefan Appelhoff <stefan.appelhoff@mailbox.org>
 #
 # License: BSD (3-clause)
 import glob
@@ -13,7 +14,7 @@
 from pathlib import Path
 from datetime import datetime
 import json
-from typing import Optional, Union
+from typing import Optional
 
 import numpy as np
 from mne.utils import warn, logger, _validate_type
@@ -224,37 +225,50 @@ class BIDSPath(object):
 
     Examples
     --------
+    Generate a BIDSPath object and inspect it
+
     >>> bids_path = BIDSPath(subject='test', session='two', task='mytask',
-                             suffix='ieeg', extension='.edf')
+    ...                      suffix='ieeg', extension='.edf')
     >>> print(bids_path.basename)
     sub-test_ses-two_task-mytask_ieeg.edf
     >>> bids_path
-    BIDSPath(root: None,
+    BIDSPath(
+    root: None
+    datatype: ieeg
     basename: sub-test_ses-two_task-mytask_ieeg.edf)
-    >>> # copy and update multiple entities at once
+
+    Copy and update multiple entities at once
+
     >>> new_bids_path = bids_path.copy().update(subject='test2',
-                                                session='one')
+    ...                                         session='one')
     >>> print(new_bids_path.basename)
     sub-test2_ses-one_task-mytask_ieeg.edf
-    >>> # printing the BIDSPath will show relative path when
-    >>> # root is not set
+
+    Printing a BIDSPath will show a relative path when `root` is not set
+
     >>> print(new_bids_path)
     sub-test2/ses-one/ieeg/sub-test2_ses-one_task-mytask_ieeg.edf
-    >>> new_bids_path.update(suffix='channels', extension='.tsv')
-    >>> # setting suffix without an identifiable datatype will
-    >>> # result in a wildcard at the datatype directory level
+
+    Setting `suffix` without an identifiable datatype will make
+    BIDSPath try to guess the datatype
+
+    >>> new_bids_path = new_bids_path.update(suffix='channels',
+    ...                                      extension='.tsv')
     >>> print(new_bids_path)
-    sub-test2/ses-one/*/sub-test2_ses-one_task-mytask_channels.tsv
-    >>> # set a root for the BIDS dataset
-    >>> new_bids_path.update(root='/bids_dataset')
-    >>> print(new_bids_path.root)
+    sub-test2/ses-one/ieeg/sub-test2_ses-one_task-mytask_channels.tsv
+
+    You can set a new root for the BIDS dataset. Let's see what the
+    different properties look like for our object:
+
+    >>> new_bids_path = new_bids_path.update(root='/bids_dataset')
+    >>> print(new_bids_path.root.as_posix())
     /bids_dataset
     >>> print(new_bids_path.basename)
-    sub-test2_ses-one_task-mytask_ieeg.edf
+    sub-test2_ses-one_task-mytask_channels.tsv
     >>> print(new_bids_path)
-    /bids_dataset/sub-test2/ses-one/ieeg/sub-test2_ses-one_task-mytask_ieeg.edf
-    >>> print(new_bids_path.directory)
-    /bids_dataset/sub-test2/ses-one/ieeg/
+    /bids_dataset/sub-test2/ses-one/ieeg/sub-test2_ses-one_task-mytask_channels.tsv
+    >>> print(new_bids_path.directory.as_posix())
+    /bids_dataset/sub-test2/ses-one/ieeg
 
     Notes
     -----
@@ -440,7 +454,7 @@ def suffix(self, value):
         self.update(suffix=value)
 
     @property
-    def root(self) -> Optional[Union[str, Path]]:
+    def root(self) -> Optional[Path]:
         """The root directory of the BIDS dataset."""
         return self._root
 
@@ -477,12 +491,14 @@ def extension(self, value):
 
     def __str__(self):
         """Return the string representation of the path."""
-        return str(self.fpath)
+        return str(self.fpath.as_posix())
 
     def __repr__(self):
         """Representation in the style of `pathlib.Path`."""
+        root = self.root.as_posix() if self.root is not None else None
+
         return f'{self.__class__.__name__}(\n' \
-               f'root: {self.root}\n' \
+               f'root: {root}\n' \
                f'datatype: {self.datatype}\n' \
                f'basename: {self.basename})'
 
@@ -651,13 +667,13 @@ def update(self, *, check=None, **kwargs):
         :func:`mne_bids.BIDSPath`:
 
         >>> bids_path = BIDSPath(subject='test', session='two',
-                                     task='mytask', suffix='channels',
-                                     extension='.tsv')
+        ...                      task='mytask', suffix='channels',
+        ...                      extension='.tsv')
         >>> print(bids_path.basename)
         sub-test_ses-two_task-mytask_channels.tsv
         >>> # Then, one can update this `BIDSPath` object in place
-        >>> bids_path.update(acquisition='test', suffix='ieeg',
-                             extension='.vhdr', task=None)
+        >>> bids_path = bids_path.update(acquisition='test', suffix='ieeg',
+        ...                              extension='.vhdr', task=None)
         >>> print(bids_path.basename)
         sub-test_ses-two_acq-test_ieeg.vhdr
         """
@@ -1147,16 +1163,16 @@ def get_entities_from_fname(fname, on_error='raise'):
     --------
     >>> fname = 'sub-01_ses-exp_run-02_meg.fif'
     >>> get_entities_from_fname(fname)
-    {'subject': '01',
-    'session': 'exp',
-    'task': None,
-    'acquisition': None,
-    'run': '02',
-    'processing': None,
-    'space': None,
-    'recording': None,
-    'split': None,
-    'suffix': 'meg'}
+    {'subject': '01', \
+'session': 'exp', \
+'task': None, \
+'acquisition': None, \
+'run': '02', \
+'processing': None, \
+'space': None, \
+'recording': None, \
+'split': None, \
+'suffix': 'meg'}
     """
     if on_error not in ('warn', 'raise', 'ignore'):
         raise ValueError(f'Acceptable values for on_error are: warn, raise, '
@@ -1398,12 +1414,12 @@ def get_entity_vals(root, entity_key, *, ignore_subjects='emptyroom',
 
     Examples
     --------
-    >>> root = os.path.expanduser('~/mne_data/eeg_matchingpennies')
+    >>> root = Path('./mne_bids/tests/data/tiny_bids').absolute()
     >>> entity_key = 'subject'
     >>> get_entity_vals(root, entity_key)
-    ['05', '06', '07', '08', '09', '10', '11']
+    ['01']
     >>> get_entity_vals(root, entity_key, with_key=True)
-    ['sub-05', 'sub-06', 'sub-07', 'sub-08', 'sub-09', 'sub-10', 'sub-11']
+    ['sub-01']
 
     Notes
     -----
diff --git a/mne_bids/sidecar_updates.py b/mne_bids/sidecar_updates.py
index 551c32b84..169668a31 100644
--- a/mne_bids/sidecar_updates.py
+++ b/mne_bids/sidecar_updates.py
@@ -1,7 +1,9 @@
 """Update BIDS directory structures and sidecar files meta data."""
 # Authors: Adam Li <adam2392@gmail.com>
 #          Austin Hurst <mynameisaustinhurst@gmail.com>
+#          Stefan Appelhoff <stefan.appelhoff@mailbox.org>
 #          mne-bids developers
+#
 # License: BSD (3-clause)
 
 import json
@@ -71,17 +73,15 @@ def update_sidecar_json(bids_path, entries, verbose=True):
 
     Examples
     --------
-    >>> # update sidecar json file
-    >>> bids_path = BIDSPath(root='./', subject='001', session='001',
-                             task='test', run='01', suffix='ieeg',
-                             extension='.json')
-    >>> entries = {'PowerLineFrequency': 50}
-    >>> update_sidecar_json(bids_path, entries)
-    >>> # update sidecar coordsystem json file
-    >>> bids_path = BIDSPath(root='./', subject='001', session='001',
-                             suffix='coordsystem', extension='.json')
-    >>> entries = {'iEEGCoordinateSystem,': 'Other'}
-    >>> update_sidecar_json(bids_path, entries)
+    Update a sidecar JSON file
+
+    >>> from pathlib import Path
+    >>> root = Path('./mne_bids/tests/data/tiny_bids').absolute()
+    >>> bids_path = BIDSPath(subject='01', task='rest', session='eeg',
+    ...                      suffix='eeg', extension='.json', root=root)
+    >>> entries = {'PowerLineFrequency': 60}
+    >>> update_sidecar_json(bids_path, entries, verbose=False)
+
     """
     # get all matching json files
     bids_path = bids_path.copy()
@@ -135,8 +135,7 @@ def _update_sidecar(sidecar_fname, key, val):
     with open(sidecar_fname, 'r', encoding='utf-8-sig') as fin:
         sidecar_json = json.load(fin)
     sidecar_json[key] = val
-    with open(sidecar_fname, 'w', encoding='utf-8') as fout:
-        json.dump(sidecar_json, fout)
+    _write_json(sidecar_fname, sidecar_json, overwrite=True, verbose=False)
 
 
 def update_anat_landmarks(bids_path, landmarks):
@@ -246,7 +245,6 @@ def update_anat_landmarks(bids_path, landmarks):
 
     bids_path_json = bids_path.copy().update(extension='.json')
     if not bids_path_json.fpath.exists():  # Must exist before we can update it
-        with bids_path_json.fpath.open('w', encoding='utf-8') as f:
-            json.dump(dict(), f)
+        _write_json(bids_path_json.fpath, dict())
 
     update_sidecar_json(bids_path=bids_path_json, entries=mri_json)
diff --git a/mne_bids/tests/data/tiny_bids/README b/mne_bids/tests/data/tiny_bids/README
new file mode 100644
index 000000000..ce5b9ab17
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/README
@@ -0,0 +1,6 @@
+References
+----------
+Appelhoff, S., Sanderson, M., Brooks, T., Vliet, M., Quentin, R., Holdgraf, C., Chaumon, M., Mikulan, E., Tavabi, K., Höchenberger, R., Welke, D., Brunner, C., Rockhill, A., Larson, E., Gramfort, A. and Jas, M. (2019). MNE-BIDS: Organizing electrophysiological data into the BIDS format and facilitating their analysis. Journal of Open Source Software 4: (1896). https://doi.org/10.21105/joss.01896
+
+Pernet, C. R., Appelhoff, S., Gorgolewski, K. J., Flandin, G., Phillips, C., Delorme, A., Oostenveld, R. (2019). EEG-BIDS, an extension to the brain imaging data structure for electroencephalography. Scientific Data, 6, 103. https://doi.org/10.1038/s41597-019-0104-8
+
diff --git a/mne_bids/tests/data/tiny_bids/code/make_tiny_bids_dataset.py b/mne_bids/tests/data/tiny_bids/code/make_tiny_bids_dataset.py
new file mode 100644
index 000000000..9b27b6620
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/code/make_tiny_bids_dataset.py
@@ -0,0 +1,62 @@
+"""Code used to generate the tiny_bids dataset."""
+# %%
+import json
+import os
+import os.path as op
+
+import mne
+import numpy as np
+
+import mne_bids
+from mne_bids import BIDSPath, write_raw_bids
+
+data_path = mne.datasets.testing.data_path()
+vhdr_fname = op.join(data_path, "montage", "bv_dig_test.vhdr")
+captrak_path = op.join(data_path, "montage", "captrak_coords.bvct")
+
+mne_bids_root = os.sep.join(mne_bids.__file__.split("/")[:-2])
+tiny_bids = op.join(mne_bids_root, "mne_bids", "tests", "data", "tiny_bids")
+os.makedirs(tiny_bids, exist_ok=True)
+
+bids_path = BIDSPath(subject="01", task="rest", session="eeg", root=tiny_bids)
+
+# %%
+raw = mne.io.read_raw_brainvision(vhdr_fname)
+montage = mne.channels.read_dig_captrak(captrak_path)
+
+raw.set_channel_types(dict(ECG="ecg", HEOG="eog", VEOG="eog"))
+raw.set_montage(montage)
+raw.info["line_freq"] = 50
+
+raw.info["subject_info"] = {
+    "id": 1,
+    "last_name": "Musterperson",
+    "first_name": "Maxi",
+    "middle_name": "Luka",
+    "birthday": (1970, 10, 20),
+    "sex": 2,
+    "hand": 3,
+}
+
+raw.set_annotations(None)
+events = np.array([[0, 0, 1], [1000, 0, 2]])
+event_id = {"start_experiment": 1, "show_stimulus": 2}
+
+# %%
+
+write_raw_bids(
+    raw, bids_path, events_data=events, event_id=event_id, overwrite=True
+)
+
+# %%
+
+dataset_description_json = op.join(tiny_bids, "dataset_description.json")
+with open(dataset_description_json, "r") as fin:
+    ds_json = json.load(fin)
+
+ds_json["Name"] = "tiny_bids"
+ds_json["Authors"] = ["MNE-BIDS Developers", "And Friends"]
+
+with open(dataset_description_json, "w") as fout:
+    json.dump(ds_json, fout, indent=4)
+    fout.write("\n")
diff --git a/mne_bids/tests/data/tiny_bids/dataset_description.json b/mne_bids/tests/data/tiny_bids/dataset_description.json
new file mode 100644
index 000000000..71532911e
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/dataset_description.json
@@ -0,0 +1,9 @@
+{
+    "Name": "tiny_bids",
+    "BIDSVersion": "1.6.0",
+    "DatasetType": "raw",
+    "Authors": [
+        "MNE-BIDS Developers",
+        "And Friends"
+    ]
+}
diff --git a/mne_bids/tests/data/tiny_bids/participants.json b/mne_bids/tests/data/tiny_bids/participants.json
new file mode 100644
index 000000000..de061dfc2
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/participants.json
@@ -0,0 +1,24 @@
+{
+    "participant_id": {
+        "Description": "Unique participant identifier"
+    },
+    "age": {
+        "Description": "Age of the participant at time of testing",
+        "Units": "years"
+    },
+    "sex": {
+        "Description": "Biological sex of the participant",
+        "Levels": {
+            "F": "female",
+            "M": "male"
+        }
+    },
+    "hand": {
+        "Description": "Handedness of the participant",
+        "Levels": {
+            "R": "right",
+            "L": "left",
+            "A": "ambidextrous"
+        }
+    }
+}
diff --git a/mne_bids/tests/data/tiny_bids/participants.tsv b/mne_bids/tests/data/tiny_bids/participants.tsv
new file mode 100644
index 000000000..75086fe10
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/participants.tsv
@@ -0,0 +1,2 @@
+participant_id	age	sex	hand
+sub-01	29	F	A
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_coordsystem.json b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_coordsystem.json
new file mode 100644
index 000000000..b902d6fc7
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_coordsystem.json
@@ -0,0 +1,24 @@
+{
+    "EEGCoordinateSystem": "CapTrak",
+    "EEGCoordinateUnits": "m",
+    "EEGCoordinateSystemDescription": "The X-axis goes from the left preauricular point (LPA) through the right preauricular point (RPA). The Y-axis goes orthogonally to the X-axis through the nasion (NAS). The Z-axis goes orthogonally to the XY-plane through the vertex of the head. This corresponds to a \"RAS\" orientation with the origin of the coordinate system approximately between the ears. See Appendix VIII in the BIDS specification.",
+    "AnatomicalLandmarkCoordinates": {
+        "NAS": [
+            -3.788238398497924e-18,
+            0.11309931478694205,
+            -3.0814879110195774e-33
+        ],
+        "LPA": [
+            -0.09189697162389295,
+            3.078070254157709e-18,
+            0.0
+        ],
+        "RPA": [
+            0.09240077493980713,
+            -3.094945043100789e-18,
+            -6.162975822039155e-33
+        ]
+    },
+    "AnatomicalLandmarkCoordinateSystem": "CapTrak",
+    "AnatomicalLandmarkCoordinateUnits": "m"
+}
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_electrodes.tsv b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_electrodes.tsv
new file mode 100644
index 000000000..6422b897e
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_electrodes.tsv
@@ -0,0 +1,68 @@
+name	x	y	z	impedance
+Fp1	-0.03741270038437644	0.11102138145885607	0.04987088609474466	5.0
+Fp2	0.02485529277372901	0.11470061734309513	0.051792653682490544	2.0
+F7	-0.08409763256980056	0.0651383327975854	0.04885693263757247	4.0
+F3	-0.06033321416227938	0.07429454777471324	0.1003425150886266	1.0
+Fz	-0.004358766283031327	0.08568143210491122	0.12205334790141567	5.0
+F4	0.054248614498413714	0.08039407987521177	0.09908756593625902	0.0
+F8	0.07985344457502894	0.06590997733368428	0.047504910890930334	0.0
+FC5	-0.08856262271830136	0.03656538257252212	0.08223925927400842	0.0
+FC1	-0.04102029132824396	0.04689188172302073	0.13593463220555657	5.0
+FC2	0.03154947116645066	0.052194369449069106	0.13882908999751697	4.0
+FC6	0.08262912998454677	0.041103054281419346	0.0874926634879591	0.0
+T7	-0.09731968723468239	-0.0021423686071579805	0.050226741225281264	7.0
+C3	-0.07560861330060216	0.00379803246039862	0.1234494784937915	7.0
+Cz	-0.006180417265753086	0.012315925271535114	0.15916621398101838	7.0
+C4	0.06771780154881832	0.012607270994125496	0.12635776802248064	5.0
+T8	0.09380794264378244	0.003856915183230266	0.05572229320000353	3.0
+TP9	-0.08788277893731682	-0.044663525156301793	0.018366495084764893	2.0
+CP5	-0.08573650192101132	-0.03761412179890887	0.08666886062797521	2.0
+CP1	-0.04005140947629612	-0.03233107162343741	0.15014596318924497	1.0
+CP2	0.031717794003817336	-0.0296088007148207	0.15221703399068814	0.0
+CP6	0.08561136739245928	-0.02720456615478355	0.0902401015260155	0.0
+TP10	0.08961349613268568	-0.039552949075016205	0.019334677566709556	6.0
+P7	-0.07806326604115213	-0.07056190192615615	0.054534433604549515	2.0
+P3	-0.05988675497167928	-0.07014191680061976	0.11264449281813038	3.0
+Pz	0.0006598293180978853	-0.06804813714721136	0.1401607191300863	3.0
+P4	0.05712134266236288	-0.06349053843971156	0.1161043631186527	3.0
+P8	0.07981691958558523	-0.06052077913488906	0.06169955870397669	2.0
+PO9	-0.05689512980123602	-0.10004211993311017	0.024158443841012435	0.0
+O1	-0.02968467135335781	-0.11245008371099957	0.0698530819823185	0.0
+Oz	0.0007596706595483696	-0.11571632630102933	0.07284087113946844	0.0
+O2	0.03439028693906701	-0.10937515964204104	0.07138023552971996	1.0
+PO10	0.061903361072981396	-0.09474806509500813	0.03333978523037232	1.0
+AF7	-0.06827717522853415	0.08936527746345276	0.04754798622540827	0.0
+AF3	-0.04262101269367339	0.10268157306800194	0.07886835797387867	0.0
+AF4	0.03225018478101126	0.10529515184701174	0.08026648552783476	0.0
+AF8	0.05956439040238648	0.09485953374400294	0.047945480521261415	0.0
+F5	-0.07472092061394837	0.0711718724278273	0.07658228616101855	1.0
+F1	-0.034810704300574445	0.07683856227323796	0.11751875341931364	0.0
+F2	0.025336640790593185	0.0821915554814207	0.11870219411577368	1.0
+F6	0.07170582263944832	0.07278864400463472	0.07387636924196503	2.0
+FT9	-0.09501686722799514	0.0266282891146297	0.011193532499484526	4.0
+FT7	-0.09514340411749506	0.033122249460160715	0.046783546930167653	4.0
+FC3	-0.07076636427255573	0.04222010515235073	0.11253273493424133	5.0
+FC4	0.06459420065117943	0.04794650194990631	0.11446098877470175	0.0
+FT8	0.09119200553670907	0.03543463031800678	0.0495990840479741	0.0
+FT10	0.0924565546557565	0.025823362649082977	0.014698781944416511	0.0
+C5	-0.09271418986954857	-0.0008204160816824106	0.08669305289548136	0.0
+C1	-0.041067570836697036	0.007252977347652117	0.14981945629789892	2.0
+C2	0.031096077417169788	0.009822809030655128	0.15263556643976955	1.0
+C6	0.08823411500163923	0.006781675055354489	0.09062978525129138	0.0
+TP7	-0.09130133540418942	-0.03998047720710454	0.05072152381600354	0.0
+CP3	-0.07051068609538193	-0.03805150971360316	0.12118907085589545	0.0
+CPz	-0.002804681696167738	-0.032506400711086986	0.15765098791790225	0.0
+CP4	0.06857184159847507	-0.02861094380649944	0.12476974691488656	0.0
+TP8	0.09015904987363602	-0.03087949475535255	0.05580695159940414	0.0
+P5	-0.07198353757029069	-0.07069605341309865	0.08424402565103543	1.0
+P1	-0.03160865255395789	-0.06888410750316204	0.13343172651379165	0.0
+P2	0.029678055865445845	-0.06524160677056923	0.13633979302106938	0.0
+P6	0.07231997488461793	-0.061210721352081214	0.08939618967378504	0.0
+PO7	-0.05917554476252128	-0.09600963297712298	0.05901355471464929	0.0
+PO3	-0.03295276056603997	-0.09836112961335748	0.09818535662931108	0.0
+POz	0.00141250247182117	-0.09659898488597438	0.1092860795662283	2.0
+PO4	0.03732555069518968	-0.09330847523481997	0.09871963971555255	0.0
+PO8	0.061422359682971855	-0.08824937021900595	0.06730156974139692	0.0
+ECG	n/a	n/a	n/a	n/a
+HEOG	n/a	n/a	n/a	n/a
+VEOG	n/a	n/a	n/a	n/a
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_channels.tsv b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_channels.tsv
new file mode 100644
index 000000000..8c63a81de
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_channels.tsv
@@ -0,0 +1,68 @@
+name	type	units	low_cutoff	high_cutoff	description	sampling_frequency	status	status_description
+Fp1	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+Fp2	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+F7	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+F3	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+Fz	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+F4	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+F8	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FC5	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FC1	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FC2	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FC6	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+T7	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+C3	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+Cz	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+C4	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+T8	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+TP9	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+CP5	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+CP1	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+CP2	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+CP6	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+TP10	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+P7	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+P3	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+Pz	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+P4	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+P8	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+PO9	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+O1	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+Oz	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+O2	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+PO10	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+AF7	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+AF3	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+AF4	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+AF8	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+F5	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+F1	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+F2	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+F6	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FT9	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FT7	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FC3	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FC4	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FT8	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+FT10	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+C5	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+C1	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+C2	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+C6	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+TP7	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+CP3	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+CPz	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+CP4	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+TP8	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+P5	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+P1	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+P2	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+P6	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+PO7	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+PO3	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+POz	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+PO4	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+PO8	EEG	µV	0.015915494309189534	1000.0	ElectroEncephaloGram	5000.0	good	n/a
+ECG	ECG	µV	0.015915494309189534	1000.0	ElectroCardioGram	5000.0	good	n/a
+HEOG	EOG	µV	0.015915494309189534	1000.0	ElectroOculoGram	5000.0	good	n/a
+VEOG	EOG	µV	0.015915494309189534	1000.0	ElectroOculoGram	5000.0	good	n/a
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.eeg b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.eeg
new file mode 100644
index 000000000..08c6c539e
Binary files /dev/null and b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.eeg differ
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.json b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.json
new file mode 100644
index 000000000..bbfde9540
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.json
@@ -0,0 +1,18 @@
+{
+    "TaskName": "rest",
+    "Manufacturer": "BrainProducts",
+    "PowerLineFrequency": 60,
+    "SamplingFrequency": 5000.0,
+    "SoftwareFilters": "n/a",
+    "RecordingDuration": 0.9998,
+    "RecordingType": "continuous",
+    "EEGReference": "n/a",
+    "EEGGround": "n/a",
+    "EEGPlacementScheme": "based on the extended 10/20 system",
+    "EEGChannelCount": 64,
+    "EOGChannelCount": 2,
+    "ECGChannelCount": 1,
+    "EMGChannelCount": 0,
+    "MiscChannelCount": 0,
+    "TriggerChannelCount": 0
+}
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.vhdr b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.vhdr
new file mode 100644
index 000000000..c20d07297
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.vhdr
@@ -0,0 +1,251 @@
+Brain Vision Data Exchange Header File Version 1.0
+; Data created by the Vision Recorder
+
+[Common Infos]
+Codepage=UTF-8
+DataFile=sub-01_ses-eeg_task-rest_eeg.eeg
+MarkerFile=sub-01_ses-eeg_task-rest_eeg.vmrk
+DataFormat=BINARY
+; Data orientation: MULTIPLEXED=ch1,pt1, ch2,pt1 ...
+DataOrientation=MULTIPLEXED
+NumberOfChannels=67
+; Sampling interval in microseconds
+SamplingInterval=200
+
+[Binary Infos]
+BinaryFormat=INT_16
+
+[Channel Infos]
+; Each entry: Ch<Channel number>=<Name>,<Reference channel name>,
+; <Resolution in "Unit">,<Unit>, Future extensions..
+; Fields are delimited by commas, some fields might be omitted (empty).
+; Commas in channel names are coded as "\1".
+Ch1=Fp1,,0.1,µV
+Ch2=Fp2,,0.1,µV
+Ch3=F7,,0.1,µV
+Ch4=F3,,0.1,µV
+Ch5=Fz,,0.1,µV
+Ch6=F4,,0.1,µV
+Ch7=F8,,0.1,µV
+Ch8=FC5,,0.1,µV
+Ch9=FC1,,0.1,µV
+Ch10=FC2,,0.1,µV
+Ch11=FC6,,0.1,µV
+Ch12=T7,,0.1,µV
+Ch13=C3,,0.1,µV
+Ch14=Cz,,0.1,µV
+Ch15=C4,,0.1,µV
+Ch16=T8,,0.1,µV
+Ch17=TP9,,0.1,µV
+Ch18=CP5,,0.1,µV
+Ch19=CP1,,0.1,µV
+Ch20=CP2,,0.1,µV
+Ch21=CP6,,0.1,µV
+Ch22=TP10,,0.1,µV
+Ch23=P7,,0.1,µV
+Ch24=P3,,0.1,µV
+Ch25=Pz,,0.1,µV
+Ch26=P4,,0.1,µV
+Ch27=P8,,0.1,µV
+Ch28=PO9,,0.1,µV
+Ch29=O1,,0.1,µV
+Ch30=Oz,,0.1,µV
+Ch31=O2,,0.1,µV
+Ch32=PO10,,0.1,µV
+Ch33=AF7,,0.1,µV
+Ch34=AF3,,0.1,µV
+Ch35=AF4,,0.1,µV
+Ch36=AF8,,0.1,µV
+Ch37=F5,,0.1,µV
+Ch38=F1,,0.1,µV
+Ch39=F2,,0.1,µV
+Ch40=F6,,0.1,µV
+Ch41=FT9,,0.1,µV
+Ch42=FT7,,0.1,µV
+Ch43=FC3,,0.1,µV
+Ch44=FC4,,0.1,µV
+Ch45=FT8,,0.1,µV
+Ch46=FT10,,0.1,µV
+Ch47=C5,,0.1,µV
+Ch48=C1,,0.1,µV
+Ch49=C2,,0.1,µV
+Ch50=C6,,0.1,µV
+Ch51=TP7,,0.1,µV
+Ch52=CP3,,0.1,µV
+Ch53=CPz,,0.1,µV
+Ch54=CP4,,0.1,µV
+Ch55=TP8,,0.1,µV
+Ch56=P5,,0.1,µV
+Ch57=P1,,0.1,µV
+Ch58=P2,,0.1,µV
+Ch59=P6,,0.1,µV
+Ch60=PO7,,0.1,µV
+Ch61=PO3,,0.1,µV
+Ch62=POz,,0.1,µV
+Ch63=PO4,,0.1,µV
+Ch64=PO8,,0.1,µV
+Ch65=ECG,,0.1,µV
+Ch66=HEOG,,0.1,µV
+Ch67=VEOG,,0.1,µV
+
+[Comment]
+
+BrainVision Recorder Professional   -   V. 1.21.0303
+
+
+A m p l i f i e r  S e t u p
+============================
+Number of channels: 67
+Sampling Rate [Hz]: 1000
+Sampling Interval [µS]: 1000
+
+Channels
+--------
+#     Name      Phys. Chn.    Resolution / Unit   Low Cutoff [s]   High Cutoff [Hz]   Notch [Hz]    Series Res. [kOhm] Gradient         Offset
+1     Fp1         1                0.1 µV             10             1000              Off                0
+2     Fp2         2                0.1 µV             10             1000              Off                0
+3     F7          3                0.1 µV             10             1000              Off                0
+4     F3          4                0.1 µV             10             1000              Off                0
+5     Fz          5                0.1 µV             10             1000              Off                0
+6     F4          6                0.1 µV             10             1000              Off                0
+7     F8          7                0.1 µV             10             1000              Off                0
+8     FC5         8                0.1 µV             10             1000              Off                0
+9     FC1         9                0.1 µV             10             1000              Off                0
+10    FC2         10               0.1 µV             10             1000              Off                0
+11    FC6         11               0.1 µV             10             1000              Off                0
+12    T7          12               0.1 µV             10             1000              Off                0
+13    C3          13               0.1 µV             10             1000              Off                0
+14    Cz          14               0.1 µV             10             1000              Off                0
+15    C4          15               0.1 µV             10             1000              Off                0
+16    T8          16               0.1 µV             10             1000              Off                0
+17    TP9         17               0.1 µV             10             1000              Off                0
+18    CP5         18               0.1 µV             10             1000              Off                0
+19    CP1         19               0.1 µV             10             1000              Off                0
+20    CP2         20               0.1 µV             10             1000              Off                0
+21    CP6         21               0.1 µV             10             1000              Off                0
+22    TP10        22               0.1 µV             10             1000              Off                0
+23    P7          23               0.1 µV             10             1000              Off                0
+24    P3          24               0.1 µV             10             1000              Off                0
+25    Pz          25               0.1 µV             10             1000              Off                0
+26    P4          26               0.1 µV             10             1000              Off                0
+27    P8          27               0.1 µV             10             1000              Off                0
+28    PO9         28               0.1 µV             10             1000              Off                0
+29    O1          29               0.1 µV             10             1000              Off                0
+30    Oz          30               0.1 µV             10             1000              Off                0
+31    O2          31               0.1 µV             10             1000              Off                0
+32    PO10        32               0.1 µV             10             1000              Off                0
+33    AF7         33               0.1 µV             10             1000              Off                0
+34    AF3         34               0.1 µV             10             1000              Off                0
+35    AF4         35               0.1 µV             10             1000              Off                0
+36    AF8         36               0.1 µV             10             1000              Off                0
+37    F5          37               0.1 µV             10             1000              Off                0
+38    F1          38               0.1 µV             10             1000              Off                0
+39    F2          39               0.1 µV             10             1000              Off                0
+40    F6          40               0.1 µV             10             1000              Off                0
+41    FT9         41               0.1 µV             10             1000              Off                0
+42    FT7         42               0.1 µV             10             1000              Off                0
+43    FC3         43               0.1 µV             10             1000              Off                0
+44    FC4         44               0.1 µV             10             1000              Off                0
+45    FT8         45               0.1 µV             10             1000              Off                0
+46    FT10        46               0.1 µV             10             1000              Off                0
+47    C5          47               0.1 µV             10             1000              Off                0
+48    C1          48               0.1 µV             10             1000              Off                0
+49    C2          49               0.1 µV             10             1000              Off                0
+50    C6          50               0.1 µV             10             1000              Off                0
+51    TP7         51               0.1 µV             10             1000              Off                0
+52    CP3         52               0.1 µV             10             1000              Off                0
+53    CPz         53               0.1 µV             10             1000              Off                0
+54    CP4         54               0.1 µV             10             1000              Off                0
+55    TP8         55               0.1 µV             10             1000              Off                0
+56    P5          56               0.1 µV             10             1000              Off                0
+57    P1          57               0.1 µV             10             1000              Off                0
+58    P2          58               0.1 µV             10             1000              Off                0
+59    P6          59               0.1 µV             10             1000              Off                0
+60    PO7         60               0.1 µV             10             1000              Off                0
+61    PO3         61               0.1 µV             10             1000              Off                0
+62    POz         62               0.1 µV             10             1000              Off                0
+63    PO4         63               0.1 µV             10             1000              Off                0
+64    PO8         64               0.1 µV             10             1000              Off                0
+65    ECG         65               0.1 µV             10             1000              Off                0
+66    HEOG        66               0.1 µV             10             1000              Off                0
+67    VEOG        67               0.1 µV             10             1000              Off                0
+
+S o f t w a r e  F i l t e r s
+==============================
+Disabled
+
+
+Impedances Imported from actiCAP Control Software:
+Impedance [kOhm] at 11:55:00 :
+Fp1:          5
+Fp2:          2
+F7:           4
+F3:           1
+Fz:           5
+F4:           0
+F8:           0
+FC5:          0
+FC1:          5
+FC2:          4
+FC6:          0
+T7:           7
+C3:           7
+Cz:           7
+C4:           5
+T8:           3
+TP9:          2
+CP5:          2
+CP1:          1
+CP2:          0
+CP6:          0
+TP10:         6
+P7:           2
+P3:           3
+Pz:           3
+P4:           3
+P8:           2
+PO9:          0
+O1:           0
+Oz:           0
+O2:           1
+PO10:         1
+AF7:          0
+AF3:          0
+AF4:          0
+AF8:          0
+F5:           1
+F1:           0
+F2:           1
+F6:           2
+FT9:          4
+FT7:          4
+FC3:          5
+FC4:          0
+FT8:          0
+FT10:         0
+C5:           0
+C1:           2
+C2:           1
+C6:           0
+TP7:          0
+CP3:          0
+CPz:          0
+CP4:          0
+TP8:          0
+P5:           1
+P1:           0
+P2:           0
+P6:           0
+PO7:          0
+PO3:          0
+POz:          2
+PO4:          0
+PO8:          0
+ECG+:        23
+ECG-:        36
+HEOG+:        3
+HEOG-:        9
+VEOG+:        2
+VEOG-:        5
+Ref:          9
+Gnd:          1
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.vmrk b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.vmrk
new file mode 100644
index 000000000..37d201ed8
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_eeg.vmrk
@@ -0,0 +1,13 @@
+Brain Vision Data Exchange Marker File, Version 1.0
+
+[Common Infos]
+Codepage=UTF-8
+DataFile=sub-01_ses-eeg_task-rest_eeg.eeg
+
+[Marker Infos]
+; Each entry: Mk<Marker number>=<Type>,<Description>,<Position in data points>,
+; <Size in data points>, <Channel number (0 = marker is related to all channels)>
+; Fields are delimited by commas, some fields might be omitted (empty).
+; Commas in type or description text are coded as "\1".
+Mk1=New Segment,,1,1,0,20000101120000000000
+Mk2=Comment,ControlBox is not connected via USB,1,1,0
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_events.tsv b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_events.tsv
new file mode 100644
index 000000000..77fd1cd00
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/eeg/sub-01_ses-eeg_task-rest_events.tsv
@@ -0,0 +1,3 @@
+onset	duration	trial_type	value	sample
+0.0	0.0	start_experiment	1	0
+0.2	0.0	show_stimulus	2	1000
diff --git a/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/sub-01_ses-eeg_scans.tsv b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/sub-01_ses-eeg_scans.tsv
new file mode 100644
index 000000000..d53fe2017
--- /dev/null
+++ b/mne_bids/tests/data/tiny_bids/sub-01/ses-eeg/sub-01_ses-eeg_scans.tsv
@@ -0,0 +1,2 @@
+filename	acq_time
+eeg/sub-01_ses-eeg_task-rest_eeg.vhdr	2000-01-01T12:00:00.000000Z
diff --git a/mne_bids/tests/test_path.py b/mne_bids/tests/test_path.py
index 2954d9bba..17440cf42 100644
--- a/mne_bids/tests/test_path.py
+++ b/mne_bids/tests/test_path.py
@@ -601,10 +601,11 @@ def test_make_filenames():
     prefix_data = dict(subject='one', session='two', task='three',
                        acquisition='four', run=1, processing='six',
                        recording='seven', suffix='ieeg', extension='.json')
-    expected_str = 'sub-one_ses-two_task-three_acq-four_run-01_proc-six_rec-seven_ieeg.json'  # noqa
+    expected_str = ('sub-one_ses-two_task-three_acq-four_run-01_proc-six_'
+                    'rec-seven_ieeg.json')
     assert BIDSPath(**prefix_data).basename == expected_str
-    assert BIDSPath(**prefix_data) == op.join('sub-one', 'ses-two',
-                                              'ieeg', expected_str)
+    assert BIDSPath(**prefix_data) == (
+        Path('sub-one') / 'ses-two' / 'ieeg' / expected_str).as_posix()
 
     # subsets of keys works
     assert (BIDSPath(subject='one', task='three', run=4).basename ==
diff --git a/mne_bids/tests/test_read.py b/mne_bids/tests/test_read.py
index 1b489878e..99135093b 100644
--- a/mne_bids/tests/test_read.py
+++ b/mne_bids/tests/test_read.py
@@ -277,8 +277,7 @@ def test_get_head_mri_trans(tmpdir):
     coords['Nasion'] = coords['NAS']
     del coords['LPA'], coords['RPA'], coords['NAS']
 
-    with t1w_json_fpath.open('w', encoding='utf-8') as f:
-        json.dump(t1w_json, f)
+    _write_json(t1w_json_fpath, t1w_json, overwrite=True)
 
     estimated_trans = get_head_mri_trans(
         bids_path=bids_path,
@@ -551,8 +550,7 @@ def test_handle_chpi_reading(tmpdir):
     # cHPI frequency mismatch
     meg_json_data_freq_mismatch = meg_json_data.copy()
     meg_json_data_freq_mismatch['HeadCoilFrequency'][0] = 123
-    with open(meg_json_path, 'w', encoding='utf-8') as f:
-        json.dump(meg_json_data_freq_mismatch, f)
+    _write_json(meg_json_path, meg_json_data_freq_mismatch, overwrite=True)
 
     with pytest.raises(ValueError, match='cHPI coil frequencies'):
         raw_read = read_raw_bids(bids_path)
@@ -560,8 +558,7 @@ def test_handle_chpi_reading(tmpdir):
     # cHPI "off" according to sidecar, but present in the data
     meg_json_data_chpi_mismatch = meg_json_data.copy()
     meg_json_data_chpi_mismatch['ContinuousHeadLocalization'] = False
-    with open(meg_json_path, 'w', encoding='utf-8') as f:
-        json.dump(meg_json_data_chpi_mismatch, f)
+    _write_json(meg_json_path, meg_json_data_chpi_mismatch, overwrite=True)
 
     raw_read = read_raw_bids(bids_path)
     assert raw_read.info['hpi_subsystem'] is None
diff --git a/mne_bids/tsv_handler.py b/mne_bids/tsv_handler.py
index f43ae8008..8f05ee6fc 100644
--- a/mne_bids/tsv_handler.py
+++ b/mne_bids/tsv_handler.py
@@ -168,6 +168,7 @@ def _to_tsv(data, fname):
 
     with open(fname, 'w', encoding='utf-8-sig') as f:
         f.write(output)
+        f.write('\n')
 
 
 def _tsv_to_str(data, rows=5):
diff --git a/mne_bids/write.py b/mne_bids/write.py
index 558ec3f5a..2ebcb4008 100644
--- a/mne_bids/write.py
+++ b/mne_bids/write.py
@@ -1900,30 +1900,40 @@ def mark_bad_channels(ch_names, descriptions=None, *, bids_path,
     --------
     Mark a single channel as bad.
 
-    >>> mark_bad_channels('MEG 0112', bids_path=bids_path)
-
-    Mark multiple channels as bad.
-
-    >>> bads = ['MEG 0112', 'MEG 0131']
-    >>> mark_bad_channels(bads, bids_path=bids_path)
-
-    Mark channels as bad, and add a description as to why.
-
-    >>> ch_names = ['MEG 0112', 'MEG 0131']
-    >>> descriptions = ['Only produced noise', 'Continuously flat']
-    >>> mark_bad_channels(bads, descriptions, bbids_path=bids_path)
+    >>> root = Path('./mne_bids/tests/data/tiny_bids').absolute()
+    >>> bids_path = BIDSPath(subject='01', task='rest', session='eeg',
+    ...                      datatype='eeg', root=root)
+    >>> mark_bad_channels('C4', bids_path=bids_path, verbose=False)
+    Processing channel C4:
+        status: bad
+        description: n/a
+
+    Mark multiple channels as bad, and add a description as to why.
+
+    >>> bads = ['C3', 'PO10']
+    >>> descriptions = ['very noisy', 'continuously flat']
+    >>> mark_bad_channels(bads, descriptions, bids_path=bids_path,
+    ...                   verbose=False)
+    Processing channel C3:
+        status: bad
+        description: very noisy
+    Processing channel PO10:
+        status: bad
+        description: continuously flat
 
     Mark two channels as bad, and mark all others as good by setting
     ``overwrite=True``.
 
-    >>> bads = ['MEG 0112', 'MEG 0131']
-    >>> mark_bad_channels(bads, bids_path=bids_path, overwrite=True)
+    >>> bads = ['C3', 'C4']
+    >>> mark_bad_channels(bads, bids_path=bids_path, # doctest: +SKIP
+    ...                   overwrite=True, verbose=False)
 
     Mark all channels as good by passing an empty list of bad channels, and
     setting ``overwrite=True``.
 
-    >>> mark_bad_channels([], bids_path=bids_path, overwrite=True)
-
+    >>> mark_bad_channels([], bids_path=bids_path, overwrite=True,
+    ...                   verbose=False)
+    Resetting status and description for all channels.
     """
     if not ch_names and not overwrite:
         raise ValueError('You did not pass a channel name, but set '
@@ -2012,10 +2022,13 @@ def write_meg_calibration(calibration, bids_path, verbose=None):
 
     Examples
     --------
-    >>> calibration = mne.preprocessing.read_fine_calibration('sss_cal.dat')
-    >>> bids_path = BIDSPath(subject='01', session='test', root='/data')
-    >>> write_meg_calibration(calibration, bids_path)
-    """
+    >>> data_path = mne.datasets.testing.data_path(download=False)
+    >>> calibration_fname = op.join(data_path, 'SSS', 'sss_cal_3053.dat')
+    >>> bids_path = BIDSPath(subject='01', session='test',
+    ...                      root=op.join(data_path, 'mne_bids'))
+    >>> write_meg_calibration(calibration_fname, bids_path) # doctest: +ELLIPSIS
+    Writing fine-calibration file to ...sub-01_ses-test_acq-calibration_meg.dat...
+    """  # noqa: E501
     if bids_path.root is None or bids_path.subject is None:
         raise ValueError('bids_path must have root and subject set.')
     if bids_path.datatype not in (None, 'meg'):
@@ -2066,9 +2079,12 @@ def write_meg_crosstalk(fname, bids_path, verbose=None):
 
     Examples
     --------
-    >>> crosstalk_fname = 'ct_sparse.fif'
-    >>> bids_path = BIDSPath(subject='01', session='test', root='/data')
-    >>> write_megcrosstalk(crosstalk_fname, bids_path)
+    >>> data_path = mne.datasets.testing.data_path(download=False)
+    >>> crosstalk_fname = op.join(data_path, 'SSS', 'ct_sparse.fif')
+    >>> bids_path = BIDSPath(subject='01', session='test',
+    ...                      root=op.join(data_path, 'mne_bids'))
+    >>> write_meg_crosstalk(crosstalk_fname, bids_path) # doctest: +ELLIPSIS
+    Writing crosstalk file to ...sub-01_ses-test_acq-crosstalk_meg.fif
     """
     if bids_path.root is None or bids_path.subject is None:
         raise ValueError('bids_path must have root and subject set.')