diff --git a/guidata/tests/_all_tests.py b/guidata/tests/_all_tests.py
deleted file mode 100644
index 8cc46da..0000000
--- a/guidata/tests/_all_tests.py
+++ /dev/null
@@ -1,52 +0,0 @@
-# -*- coding: utf-8 -*-
-
-"""
-Run all tests in unattended mode
-"""
-
-import argparse
-import os
-import os.path as osp
-
-import guidata
-from guidata import __version__
-from guidata.guitest import get_tests
-
-
-def run_all_tests(args="", contains="", timeout=None):
-    """Run all guidata tests"""
-    all_testmodules = get_tests(guidata, "batch")
-    testmodules = [
-        tmod
-        for tmod in all_testmodules
-        if not osp.samefile(tmod.path, __file__) and contains in tmod.path
-    ]
-    tnb = len(testmodules)
-    print("*** guidata automatic unit tests ***")
-    print("")
-    print("Test parameters:")
-    print(f"  Selected {tnb} tests ({len(all_testmodules) - 1} total available)")
-    print("  Environment:")
-    for vname in ("PYTHONPATH", "DEBUG"):
-        print(f"    {vname}={os.environ.get(vname, '')}")
-    print("")
-    print("Please wait while test scripts are executed (a few minutes).")
-    print("Only error messages will be printed out (no message = test OK).")
-    print("")
-    for idx, testmodule in enumerate(testmodules):
-        rpath = osp.relpath(testmodule.path, osp.dirname(guidata.__file__))
-        print(f"===[{(idx+1):02d}/{tnb:02d}]=== 🍺 Running test [{rpath}]")
-        testmodule.run(args=args, timeout=timeout)
-
-
-def run():
-    """Parse arguments and run tests"""
-    parser = argparse.ArgumentParser(description="Run all test in unattended mode")
-    parser.add_argument("--contains", default="")
-    parser.add_argument("--timeout", type=int, default=240)
-    args = parser.parse_args()
-    run_all_tests("--mode unattended --verbose quiet", args.contains, args.timeout)
-
-
-if __name__ == "__main__":
-    run()
diff --git a/guidata/tests/dataset/__init__.py b/guidata/tests/dataset/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/guidata/tests/test_activable_dataset.py b/guidata/tests/dataset/test_activable_dataset.py
similarity index 96%
rename from guidata/tests/test_activable_dataset.py
rename to guidata/tests/dataset/test_activable_dataset.py
index 96612c2..0997115 100644
--- a/guidata/tests/test_activable_dataset.py
+++ b/guidata/tests/dataset/test_activable_dataset.py
@@ -1,60 +1,60 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-ActivableDataSet example
-
-Warning: ActivableDataSet objects were made to be integrated inside GUI layouts.
-So this example with dialog boxes may be confusing.
---> see tests/editgroupbox.py to understand the activable dataset usage
-"""
-
-# When editing, all items are shown.
-# When showing dataset in read-only mode (e.g. inside another layout), all items
-# are shown except the enable item.
-
-import guidata.dataset as gds
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context
-
-# guitest: show
-
-
-class Parameters(gds.ActivableDataSet):
-    """
-    Example
-    <b>Activable dataset example</b>
-    """
-
-    def __init__(self, title=None, comment=None, icon=""):
-        gds.ActivableDataSet.__init__(self, title, comment, icon)
-
-    enable = gds.BoolItem(
-        "Enable parameter set",
-        help="If disabled, the following parameters will be ignored",
-        default=False,
-    )
-    param0 = gds.ChoiceItem("Param 0", ["choice #1", "choice #2", "choice #3"])
-    param1 = gds.FloatItem("Param 1", default=0, min=0)
-    param2 = gds.FloatItem("Param 2", default=0.93)
-    color = gds.ColorItem("Color", default="red")
-
-
-Parameters.active_setup()
-
-
-def test_activable_dataset():
-    """Test activable dataset"""
-    with qt_app_context():
-        prm = Parameters()
-        prm.set_writeable()
-        prm.edit()
-        prm.set_readonly()
-        prm.view()
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_activable_dataset()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+ActivableDataSet example
+
+Warning: ActivableDataSet objects were made to be integrated inside GUI layouts.
+So this example with dialog boxes may be confusing.
+--> see tests/editgroupbox.py to understand the activable dataset usage
+"""
+
+# When editing, all items are shown.
+# When showing dataset in read-only mode (e.g. inside another layout), all items
+# are shown except the enable item.
+
+import guidata.dataset as gds
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context
+
+# guitest: show
+
+
+class Parameters(gds.ActivableDataSet):
+    """
+    Example
+    <b>Activable dataset example</b>
+    """
+
+    def __init__(self, title=None, comment=None, icon=""):
+        gds.ActivableDataSet.__init__(self, title, comment, icon)
+
+    enable = gds.BoolItem(
+        "Enable parameter set",
+        help="If disabled, the following parameters will be ignored",
+        default=False,
+    )
+    param0 = gds.ChoiceItem("Param 0", ["choice #1", "choice #2", "choice #3"])
+    param1 = gds.FloatItem("Param 1", default=0, min=0)
+    param2 = gds.FloatItem("Param 2", default=0.93)
+    color = gds.ColorItem("Color", default="red")
+
+
+Parameters.active_setup()
+
+
+def test_activable_dataset():
+    """Test activable dataset"""
+    with qt_app_context():
+        prm = Parameters()
+        prm.set_writeable()
+        prm.edit()
+        prm.set_readonly()
+        prm.view()
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_activable_dataset()
diff --git a/guidata/tests/test_activable_items.py b/guidata/tests/dataset/test_activable_items.py
similarity index 96%
rename from guidata/tests/test_activable_items.py
rename to guidata/tests/dataset/test_activable_items.py
index e6b27a2..7f70bfd 100644
--- a/guidata/tests/test_activable_items.py
+++ b/guidata/tests/dataset/test_activable_items.py
@@ -1,39 +1,39 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-Example with activable items: items which active state is changed depending
-on another item's value.
-"""
-
-# guitest: show
-
-from guidata.dataset import ChoiceItem, DataSet, FloatItem, FuncProp, GetAttrProp
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context
-
-choices = (("A", "Choice #1: A"), ("B", "Choice #2: B"), ("C", "Choice #3: C"))
-
-
-class Parameters(DataSet):
-    """Example dataset"""
-
-    _prop = GetAttrProp("choice")
-    choice = ChoiceItem("Choice", choices).set_prop("display", store=_prop)
-    x1 = FloatItem("x1")
-    x2 = FloatItem("x2").set_prop("display", active=FuncProp(_prop, lambda x: x == "B"))
-    x3 = FloatItem("x3").set_prop("display", active=FuncProp(_prop, lambda x: x == "C"))
-
-
-def test_activable_items():
-    """Test activable items"""
-    with qt_app_context():
-        test = Parameters()
-        test.edit()
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_activable_items()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+Example with activable items: items which active state is changed depending
+on another item's value.
+"""
+
+# guitest: show
+
+from guidata.dataset import ChoiceItem, DataSet, FloatItem, FuncProp, GetAttrProp
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context
+
+choices = (("A", "Choice #1: A"), ("B", "Choice #2: B"), ("C", "Choice #3: C"))
+
+
+class Parameters(DataSet):
+    """Example dataset"""
+
+    _prop = GetAttrProp("choice")
+    choice = ChoiceItem("Choice", choices).set_prop("display", store=_prop)
+    x1 = FloatItem("x1")
+    x2 = FloatItem("x2").set_prop("display", active=FuncProp(_prop, lambda x: x == "B"))
+    x3 = FloatItem("x3").set_prop("display", active=FuncProp(_prop, lambda x: x == "C"))
+
+
+def test_activable_items():
+    """Test activable items"""
+    with qt_app_context():
+        test = Parameters()
+        test.edit()
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_activable_items()
diff --git a/guidata/tests/test_all_features.py b/guidata/tests/dataset/test_all_features.py
similarity index 96%
rename from guidata/tests/test_all_features.py
rename to guidata/tests/dataset/test_all_features.py
index f6ede8f..117c2ed 100644
--- a/guidata/tests/test_all_features.py
+++ b/guidata/tests/dataset/test_all_features.py
@@ -1,142 +1,142 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-All guidata item/group features demo
-"""
-
-# guitest: show
-
-import atexit
-import shutil
-import tempfile
-
-import numpy as np
-
-import guidata.dataset as gds
-from guidata.dataset.qtitemwidgets import DataSetWidget
-from guidata.dataset.qtwidgets import DataSetEditLayout, DataSetShowLayout
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context
-
-# Creating temporary files and registering cleanup functions
-TEMPDIR = tempfile.mkdtemp(prefix="test_")
-atexit.register(shutil.rmtree, TEMPDIR)
-FILE_ETA = tempfile.NamedTemporaryFile(suffix=".eta", dir=TEMPDIR)
-atexit.register(FILE_ETA.close)
-FILE_CSV = tempfile.NamedTemporaryFile(suffix=".csv", dir=TEMPDIR)
-atexit.register(FILE_CSV.close)
-
-
-class SubDataSet(gds.DataSet):
-    dir = gds.DirectoryItem("Directory", TEMPDIR)
-    fname = gds.FileOpenItem("Single file (open)", ("csv", "eta"), FILE_CSV.name)
-    fnames = gds.FilesOpenItem("Multiple files", "csv", FILE_CSV.name)
-    fname_s = gds.FileSaveItem("Single file (save)", "eta", FILE_ETA.name)
-
-
-class SubDataSetWidget(DataSetWidget):
-    klass = SubDataSet
-
-
-class SubDataSetItem(gds.ObjectItem):
-    klass = SubDataSet
-
-
-DataSetEditLayout.register(SubDataSetItem, SubDataSetWidget)
-DataSetShowLayout.register(SubDataSetItem, SubDataSetWidget)
-
-
-class Parameters(gds.DataSet):
-    """
-    DataSet test
-    The following text is the DataSet 'comment': <br>Plain text or
-    <b>rich text<sup>2</sup></b> are both supported,
-    as well as special characters (α, β, γ, δ, ...)
-    """
-
-    dict_ = gds.DictItem(
-        "dict_item",
-        {
-            "strings_col": ["a", "b", "c"],
-            "_col": [1, 2.0, 3],
-            "float_col": 1.0,
-        },
-    )
-    string = gds.StringItem("String")
-    string_regexp = gds.StringItem("String", regexp=r"^[a-z]+[0-9]$", default="abcd9")
-    password = gds.StringItem("Password", password=True)
-    text = gds.TextItem("Text")
-    _bg = gds.BeginGroup("A sub group")
-    float_slider = gds.FloatItem(
-        "Float (with slider)", default=0.5, min=0, max=1, step=0.01, slider=True
-    )
-    fl1 = gds.FloatItem(
-        "Current", default=10.0, min=1, max=30, unit="mA", help="Threshold current"
-    )
-    fl2 = gds.FloatItem("Float (col=1)", default=1.0, min=1, max=1).set_pos(col=1)
-    fl3 = gds.FloatItem("Not checked float").set_prop("data", check_value=False)
-    bool1 = gds.BoolItem("Boolean option without label")
-    bool2 = gds.BoolItem("Boolean option with label", "Label").set_pos(col=1, colspan=2)
-    color = gds.ColorItem("Color", default="red")
-    choice1 = gds.ChoiceItem(
-        "Single choice (radio)",
-        [(16, "first choice"), (32, "second choice"), (64, "third choice")],
-        radio=True,
-    ).set_pos(col=1, colspan=2)
-    choice2 = gds.ChoiceItem(
-        "Single choice (combo)",
-        [(16, "first choice"), (32, "second choice"), (64, "third choice")],
-    ).set_pos(col=1, colspan=2)
-    _eg = gds.EndGroup("A sub group")
-    floatarray = gds.FloatArrayItem(
-        "Float array", default=np.ones((50, 5), float), format=" %.2e "
-    ).set_pos(col=1)
-    g0 = gds.BeginTabGroup("group")
-    mchoice1 = gds.MultipleChoiceItem(
-        "MC type 1", ["first choice", "second choice", "third choice"]
-    ).vertical(2)
-    mchoice2 = (
-        gds.ImageChoiceItem(
-            "MC type 2",
-            [
-                ("rect", "first choice", "gif.png"),
-                ("ell", "second choice", "txt.png"),
-                ("qcq", "third choice", "file.png"),
-            ],
-        )
-        .set_pos(col=1)
-        .set_prop("display", icon="file.png")
-    )
-    mchoice3 = gds.MultipleChoiceItem(
-        "MC type 3", [str(i) for i in range(10)]
-    ).horizontal(2)
-    eg0 = gds.EndTabGroup("group")
-    integer_slider = gds.IntItem(
-        "Integer (with slider)", default=5, min=-50, max=50, slider=True
-    )
-    integer = gds.IntItem("Integer", default=5, min=3, max=6).set_pos(col=1)
-
-
-def test_all_features():
-    """Test all guidata item/group features"""
-    with qt_app_context():
-        prm1 = Parameters()
-        prm1.floatarray[:, 0] = np.linspace(-5, 5, 50)
-        execenv.print(prm1)
-
-        if prm1.edit():
-            prm1.edit()
-            execenv.print(prm1)
-        prm1.view()
-
-        prm2 = Parameters.create(integer=10101010, string="Using create class method")
-        print(prm2)
-
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_all_features()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+All guidata item/group features demo
+"""
+
+# guitest: show
+
+import atexit
+import shutil
+import tempfile
+
+import numpy as np
+
+import guidata.dataset as gds
+from guidata.dataset.qtitemwidgets import DataSetWidget
+from guidata.dataset.qtwidgets import DataSetEditLayout, DataSetShowLayout
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context
+
+# Creating temporary files and registering cleanup functions
+TEMPDIR = tempfile.mkdtemp(prefix="test_")
+atexit.register(shutil.rmtree, TEMPDIR)
+FILE_ETA = tempfile.NamedTemporaryFile(suffix=".eta", dir=TEMPDIR)
+atexit.register(FILE_ETA.close)
+FILE_CSV = tempfile.NamedTemporaryFile(suffix=".csv", dir=TEMPDIR)
+atexit.register(FILE_CSV.close)
+
+
+class SubDataSet(gds.DataSet):
+    dir = gds.DirectoryItem("Directory", TEMPDIR)
+    fname = gds.FileOpenItem("Single file (open)", ("csv", "eta"), FILE_CSV.name)
+    fnames = gds.FilesOpenItem("Multiple files", "csv", FILE_CSV.name)
+    fname_s = gds.FileSaveItem("Single file (save)", "eta", FILE_ETA.name)
+
+
+class SubDataSetWidget(DataSetWidget):
+    klass = SubDataSet
+
+
+class SubDataSetItem(gds.ObjectItem):
+    klass = SubDataSet
+
+
+DataSetEditLayout.register(SubDataSetItem, SubDataSetWidget)
+DataSetShowLayout.register(SubDataSetItem, SubDataSetWidget)
+
+
+class Parameters(gds.DataSet):
+    """
+    DataSet test
+    The following text is the DataSet 'comment': <br>Plain text or
+    <b>rich text<sup>2</sup></b> are both supported,
+    as well as special characters (α, β, γ, δ, ...)
+    """
+
+    dict_ = gds.DictItem(
+        "dict_item",
+        {
+            "strings_col": ["a", "b", "c"],
+            "_col": [1, 2.0, 3],
+            "float_col": 1.0,
+        },
+    )
+    string = gds.StringItem("String")
+    string_regexp = gds.StringItem("String", regexp=r"^[a-z]+[0-9]$", default="abcd9")
+    password = gds.StringItem("Password", password=True)
+    text = gds.TextItem("Text")
+    _bg = gds.BeginGroup("A sub group")
+    float_slider = gds.FloatItem(
+        "Float (with slider)", default=0.5, min=0, max=1, step=0.01, slider=True
+    )
+    fl1 = gds.FloatItem(
+        "Current", default=10.0, min=1, max=30, unit="mA", help="Threshold current"
+    )
+    fl2 = gds.FloatItem("Float (col=1)", default=1.0, min=1, max=1).set_pos(col=1)
+    fl3 = gds.FloatItem("Not checked float").set_prop("data", check_value=False)
+    bool1 = gds.BoolItem("Boolean option without label")
+    bool2 = gds.BoolItem("Boolean option with label", "Label").set_pos(col=1, colspan=2)
+    color = gds.ColorItem("Color", default="red")
+    choice1 = gds.ChoiceItem(
+        "Single choice (radio)",
+        [(16, "first choice"), (32, "second choice"), (64, "third choice")],
+        radio=True,
+    ).set_pos(col=1, colspan=2)
+    choice2 = gds.ChoiceItem(
+        "Single choice (combo)",
+        [(16, "first choice"), (32, "second choice"), (64, "third choice")],
+    ).set_pos(col=1, colspan=2)
+    _eg = gds.EndGroup("A sub group")
+    floatarray = gds.FloatArrayItem(
+        "Float array", default=np.ones((50, 5), float), format=" %.2e "
+    ).set_pos(col=1)
+    g0 = gds.BeginTabGroup("group")
+    mchoice1 = gds.MultipleChoiceItem(
+        "MC type 1", ["first choice", "second choice", "third choice"]
+    ).vertical(2)
+    mchoice2 = (
+        gds.ImageChoiceItem(
+            "MC type 2",
+            [
+                ("rect", "first choice", "gif.png"),
+                ("ell", "second choice", "txt.png"),
+                ("qcq", "third choice", "file.png"),
+            ],
+        )
+        .set_pos(col=1)
+        .set_prop("display", icon="file.png")
+    )
+    mchoice3 = gds.MultipleChoiceItem(
+        "MC type 3", [str(i) for i in range(10)]
+    ).horizontal(2)
+    eg0 = gds.EndTabGroup("group")
+    integer_slider = gds.IntItem(
+        "Integer (with slider)", default=5, min=-50, max=50, slider=True
+    )
+    integer = gds.IntItem("Integer", default=5, min=3, max=6).set_pos(col=1)
+
+
+def test_all_features():
+    """Test all guidata item/group features"""
+    with qt_app_context():
+        prm1 = Parameters()
+        prm1.floatarray[:, 0] = np.linspace(-5, 5, 50)
+        execenv.print(prm1)
+
+        if prm1.edit():
+            prm1.edit()
+            execenv.print(prm1)
+        prm1.view()
+
+        prm2 = Parameters.create(integer=10101010, string="Using create class method")
+        print(prm2)
+
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_all_features()
diff --git a/guidata/tests/test_all_items.py b/guidata/tests/dataset/test_all_items.py
similarity index 96%
rename from guidata/tests/test_all_items.py
rename to guidata/tests/dataset/test_all_items.py
index 56d1474..c0094a5 100644
--- a/guidata/tests/test_all_items.py
+++ b/guidata/tests/dataset/test_all_items.py
@@ -1,118 +1,118 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-All guidata DataItem objects demo
-
-A DataSet object is a set of parameters of various types (integer, float,
-boolean, string, etc.) which may be edited in a dialog box thanks to the
-'edit' method. Parameters are defined by assigning DataItem objects to a
-DataSet class definition: each parameter type has its own DataItem class
-(IntItem for integers, FloatItem for floats, StringItem for strings, etc.)
-"""
-
-# guitest: show
-
-import atexit
-import datetime
-import shutil
-import tempfile
-
-import numpy as np
-
-import guidata.dataset as gds
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context
-
-# Creating temporary files and registering cleanup functions
-TEMPDIR = tempfile.mkdtemp(prefix="test_")
-atexit.register(shutil.rmtree, TEMPDIR)
-FILE_ETA = tempfile.NamedTemporaryFile(suffix=".eta", dir=TEMPDIR)
-atexit.register(FILE_ETA.close)
-FILE_CSV = tempfile.NamedTemporaryFile(suffix=".csv", dir=TEMPDIR)
-atexit.register(FILE_CSV.close)
-
-
-class Parameters(gds.DataSet):
-    """
-    DataSet test
-    The following text is the DataSet 'comment': <br>Plain text or
-    <b>rich text<sup>2</sup></b> are both supported,
-    as well as special characters (α, β, γ, δ, ...)
-    """
-
-    dir = gds.DirectoryItem("Directory", TEMPDIR)
-    fname = gds.FileOpenItem("Open file", ("csv", "eta"), FILE_CSV.name)
-    fnames = gds.FilesOpenItem("Open files", "csv", FILE_CSV.name)
-    fname_s = gds.FileSaveItem("Save file", "eta", FILE_ETA.name)
-    string = gds.StringItem("String")
-    text = gds.TextItem("Text")
-    float_slider = gds.FloatItem(
-        "Float (with slider)", default=0.5, min=0, max=1, step=0.01, slider=True
-    )
-    integer = gds.IntItem("Integer", default=5, min=3, max=16, slider=True).set_pos(
-        col=1
-    )
-    dtime = gds.DateTimeItem("Date/time", default=datetime.datetime(2010, 10, 10))
-    date = gds.DateItem("Date", default=datetime.date(2010, 10, 10)).set_pos(col=1)
-    bool1 = gds.BoolItem("Boolean option without label")
-    bool2 = gds.BoolItem("Boolean option with label", "Label")
-    _bg = gds.BeginGroup("A sub group")
-    color = gds.ColorItem("Color", default="red")
-    choice = gds.ChoiceItem(
-        "Single choice 1",
-        [("16", "first choice"), ("32", "second choice"), ("64", "third choice")],
-    )
-    mchoice2 = gds.ImageChoiceItem(
-        "Single choice 2",
-        [
-            ("rect", "first choice", "gif.png"),
-            ("ell", "second choice", "txt.png"),
-            ("qcq", "third choice", "file.png"),
-        ],
-    )
-    _eg = gds.EndGroup("A sub group")
-    floatarray = gds.FloatArrayItem(
-        "Float array", default=np.ones((50, 5), float), format=" %.2e "
-    ).set_pos(col=1)
-    mchoice3 = gds.MultipleChoiceItem(
-        "MC type 1", [str(i) for i in range(12)]
-    ).horizontal(4)
-    mchoice1 = (
-        gds.MultipleChoiceItem(
-            "MC type 2", ["first choice", "second choice", "third choice"]
-        )
-        .vertical(1)
-        .set_pos(col=1)
-    )
-    dictionary = gds.DictItem(
-        "Dictionary",
-        default={
-            "lkl": 2,
-            "tototo": 3,
-            "zzzz": "lklk",
-            "bool": True,
-            "float": 1.234,
-            "list": [1, 2.5, 3, "str", False, 5, {"lkl": 2, "l": [1, 2, 3]}],
-        },
-        help="This is a dictionary",
-    )
-
-
-def test_all_items():
-    """Test all DataItem objects"""
-    with qt_app_context():
-        prm = Parameters()
-
-        prm.floatarray[:, 0] = np.linspace(-5, 5, 50)
-        execenv.print(prm)
-        if prm.edit():
-            execenv.print(prm)
-        prm.view()
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_all_items()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+All guidata DataItem objects demo
+
+A DataSet object is a set of parameters of various types (integer, float,
+boolean, string, etc.) which may be edited in a dialog box thanks to the
+'edit' method. Parameters are defined by assigning DataItem objects to a
+DataSet class definition: each parameter type has its own DataItem class
+(IntItem for integers, FloatItem for floats, StringItem for strings, etc.)
+"""
+
+# guitest: show
+
+import atexit
+import datetime
+import shutil
+import tempfile
+
+import numpy as np
+
+import guidata.dataset as gds
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context
+
+# Creating temporary files and registering cleanup functions
+TEMPDIR = tempfile.mkdtemp(prefix="test_")
+atexit.register(shutil.rmtree, TEMPDIR)
+FILE_ETA = tempfile.NamedTemporaryFile(suffix=".eta", dir=TEMPDIR)
+atexit.register(FILE_ETA.close)
+FILE_CSV = tempfile.NamedTemporaryFile(suffix=".csv", dir=TEMPDIR)
+atexit.register(FILE_CSV.close)
+
+
+class Parameters(gds.DataSet):
+    """
+    DataSet test
+    The following text is the DataSet 'comment': <br>Plain text or
+    <b>rich text<sup>2</sup></b> are both supported,
+    as well as special characters (α, β, γ, δ, ...)
+    """
+
+    dir = gds.DirectoryItem("Directory", TEMPDIR)
+    fname = gds.FileOpenItem("Open file", ("csv", "eta"), FILE_CSV.name)
+    fnames = gds.FilesOpenItem("Open files", "csv", FILE_CSV.name)
+    fname_s = gds.FileSaveItem("Save file", "eta", FILE_ETA.name)
+    string = gds.StringItem("String")
+    text = gds.TextItem("Text")
+    float_slider = gds.FloatItem(
+        "Float (with slider)", default=0.5, min=0, max=1, step=0.01, slider=True
+    )
+    integer = gds.IntItem("Integer", default=5, min=3, max=16, slider=True).set_pos(
+        col=1
+    )
+    dtime = gds.DateTimeItem("Date/time", default=datetime.datetime(2010, 10, 10))
+    date = gds.DateItem("Date", default=datetime.date(2010, 10, 10)).set_pos(col=1)
+    bool1 = gds.BoolItem("Boolean option without label")
+    bool2 = gds.BoolItem("Boolean option with label", "Label")
+    _bg = gds.BeginGroup("A sub group")
+    color = gds.ColorItem("Color", default="red")
+    choice = gds.ChoiceItem(
+        "Single choice 1",
+        [("16", "first choice"), ("32", "second choice"), ("64", "third choice")],
+    )
+    mchoice2 = gds.ImageChoiceItem(
+        "Single choice 2",
+        [
+            ("rect", "first choice", "gif.png"),
+            ("ell", "second choice", "txt.png"),
+            ("qcq", "third choice", "file.png"),
+        ],
+    )
+    _eg = gds.EndGroup("A sub group")
+    floatarray = gds.FloatArrayItem(
+        "Float array", default=np.ones((50, 5), float), format=" %.2e "
+    ).set_pos(col=1)
+    mchoice3 = gds.MultipleChoiceItem(
+        "MC type 1", [str(i) for i in range(12)]
+    ).horizontal(4)
+    mchoice1 = (
+        gds.MultipleChoiceItem(
+            "MC type 2", ["first choice", "second choice", "third choice"]
+        )
+        .vertical(1)
+        .set_pos(col=1)
+    )
+    dictionary = gds.DictItem(
+        "Dictionary",
+        default={
+            "lkl": 2,
+            "tototo": 3,
+            "zzzz": "lklk",
+            "bool": True,
+            "float": 1.234,
+            "list": [1, 2.5, 3, "str", False, 5, {"lkl": 2, "l": [1, 2, 3]}],
+        },
+        help="This is a dictionary",
+    )
+
+
+def test_all_items():
+    """Test all DataItem objects"""
+    with qt_app_context():
+        prm = Parameters()
+
+        prm.floatarray[:, 0] = np.linspace(-5, 5, 50)
+        execenv.print(prm)
+        if prm.edit():
+            execenv.print(prm)
+        prm.view()
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_all_items()
diff --git a/guidata/tests/test_bool_selector.py b/guidata/tests/dataset/test_bool_selector.py
similarity index 96%
rename from guidata/tests/test_bool_selector.py
rename to guidata/tests/dataset/test_bool_selector.py
index e0c7b13..6e8e582 100644
--- a/guidata/tests/test_bool_selector.py
+++ b/guidata/tests/dataset/test_bool_selector.py
@@ -1,60 +1,60 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-DataItem groups and group selection
-
-DataSet items may be included in groups (these items are then shown in group
-box widgets in the editing dialog box) and item groups may be enabled/disabled
-using one group parameter (a boolean item).
-"""
-
-# guitest: show
-
-import guidata.dataset as gds
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context
-
-prop1 = gds.ValueProp(False)
-prop2 = gds.ValueProp(False)
-
-
-class Parameters(gds.DataSet):
-    """
-    Group selection test
-    <b>Group selection example:</b>
-    """
-
-    g1 = gds.BeginGroup("group 1")
-    enable1 = gds.BoolItem(
-        "Enable parameter set #1",
-        help="If disabled, the following parameters will be ignored",
-        default=False,
-    ).set_prop("display", store=prop1)
-    prm11 = gds.FloatItem("Prm 1.1", default=0, min=0).set_prop("display", active=prop1)
-    prm12 = gds.FloatItem("Prm 1.2", default=0.93).set_prop("display", active=prop1)
-    _g1 = gds.EndGroup("group 1")
-    g2 = gds.BeginGroup("group 2")
-    enable2 = gds.BoolItem(
-        "Enable parameter set #2",
-        help="If disabled, the following parameters will be ignored",
-        default=True,
-    ).set_prop("display", store=prop2)
-    prm21 = gds.FloatItem("Prm 2.1", default=0, min=0).set_prop("display", active=prop2)
-    prm22 = gds.FloatItem("Prm 2.2", default=0.93).set_prop("display", active=prop2)
-    _g2 = gds.EndGroup("group 2")
-
-
-def test_bool_selector():
-    """Test bool selector"""
-    with qt_app_context():
-        prm = Parameters()
-        prm.edit()
-        execenv.print(prm)
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_bool_selector()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+DataItem groups and group selection
+
+DataSet items may be included in groups (these items are then shown in group
+box widgets in the editing dialog box) and item groups may be enabled/disabled
+using one group parameter (a boolean item).
+"""
+
+# guitest: show
+
+import guidata.dataset as gds
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context
+
+prop1 = gds.ValueProp(False)
+prop2 = gds.ValueProp(False)
+
+
+class Parameters(gds.DataSet):
+    """
+    Group selection test
+    <b>Group selection example:</b>
+    """
+
+    g1 = gds.BeginGroup("group 1")
+    enable1 = gds.BoolItem(
+        "Enable parameter set #1",
+        help="If disabled, the following parameters will be ignored",
+        default=False,
+    ).set_prop("display", store=prop1)
+    prm11 = gds.FloatItem("Prm 1.1", default=0, min=0).set_prop("display", active=prop1)
+    prm12 = gds.FloatItem("Prm 1.2", default=0.93).set_prop("display", active=prop1)
+    _g1 = gds.EndGroup("group 1")
+    g2 = gds.BeginGroup("group 2")
+    enable2 = gds.BoolItem(
+        "Enable parameter set #2",
+        help="If disabled, the following parameters will be ignored",
+        default=True,
+    ).set_prop("display", store=prop2)
+    prm21 = gds.FloatItem("Prm 2.1", default=0, min=0).set_prop("display", active=prop2)
+    prm22 = gds.FloatItem("Prm 2.2", default=0.93).set_prop("display", active=prop2)
+    _g2 = gds.EndGroup("group 2")
+
+
+def test_bool_selector():
+    """Test bool selector"""
+    with qt_app_context():
+        prm = Parameters()
+        prm.edit()
+        execenv.print(prm)
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_bool_selector()
diff --git a/guidata/tests/test_callbacks.py b/guidata/tests/dataset/test_callbacks.py
similarity index 96%
rename from guidata/tests/test_callbacks.py
rename to guidata/tests/dataset/test_callbacks.py
index 334020a..48c638a 100644
--- a/guidata/tests/test_callbacks.py
+++ b/guidata/tests/dataset/test_callbacks.py
@@ -1,84 +1,84 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-Demonstrates how items may trigger callbacks when activated, or how
-the list of choices may be dynamically changed.
-"""
-
-# guitest: show
-
-import guidata.dataset as gds
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context
-
-
-class Parameters(gds.DataSet):
-    """Example dataset"""
-
-    def cb_example(self, item, value):
-        execenv.print("\nitem: ", item, "\nvalue:", value)
-        if self.results is None:
-            self.results = ""
-        self.results += str(value) + "\n"
-        execenv.print("results:", self.results)
-
-    def update_x1plusx2(self, item, value):
-        execenv.print("\nitem: ", item, "\nvalue:", value)
-        if self.x1 is not None and self.x2 is not None:
-            self.x1plusx2 = self.x1 + self.x2
-        else:
-            self.x1plusx2 = None
-
-    string = gds.StringItem("String", default="foobar").set_prop(
-        "display", callback=cb_example
-    )
-    x1 = gds.FloatItem("x1").set_prop("display", callback=update_x1plusx2)
-    x2 = gds.FloatItem("x2").set_prop("display", callback=update_x1plusx2)
-    x1plusx2 = gds.FloatItem("x1+x2").set_prop("display", active=False)
-    color = gds.ColorItem("Color", default="red").set_prop(
-        "display", callback=cb_example
-    )
-
-    def choices_callback(self, item, value):
-        """Choices callback: this demonstrates how to dynamically change
-        the list of choices... even if it is not very useful in this case
-
-        Note that `None` is systematically added as the third element of
-        the returned tuples: that is to ensure the compatibility between
-        `ChoiceItem` and `ImageChoiceItem` (see `guidata.dataset.dataitems`)
-        """
-        execenv.print(f"[choices_callback]: item={item}, value={value}")
-        return [
-            (16, "first choice", None),
-            (32, "second choice", None),
-            (64, "third choice", None),
-        ]
-
-    choice = (
-        gds.ChoiceItem(
-            "Single choice",
-            choices_callback,
-            default=64,
-        )
-        .set_pos(col=1, colspan=2)
-        .set_prop("display", callback=cb_example)
-    )
-    results = gds.TextItem("Results")
-
-
-def test_callbacks():
-    """Test callbacks"""
-    with qt_app_context():
-        prm = Parameters()
-        execenv.print(prm)
-        if prm.edit():
-            execenv.print(prm)
-        prm.view()
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_callbacks()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+Demonstrates how items may trigger callbacks when activated, or how
+the list of choices may be dynamically changed.
+"""
+
+# guitest: show
+
+import guidata.dataset as gds
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context
+
+
+class Parameters(gds.DataSet):
+    """Example dataset"""
+
+    def cb_example(self, item, value):
+        execenv.print("\nitem: ", item, "\nvalue:", value)
+        if self.results is None:
+            self.results = ""
+        self.results += str(value) + "\n"
+        execenv.print("results:", self.results)
+
+    def update_x1plusx2(self, item, value):
+        execenv.print("\nitem: ", item, "\nvalue:", value)
+        if self.x1 is not None and self.x2 is not None:
+            self.x1plusx2 = self.x1 + self.x2
+        else:
+            self.x1plusx2 = None
+
+    string = gds.StringItem("String", default="foobar").set_prop(
+        "display", callback=cb_example
+    )
+    x1 = gds.FloatItem("x1").set_prop("display", callback=update_x1plusx2)
+    x2 = gds.FloatItem("x2").set_prop("display", callback=update_x1plusx2)
+    x1plusx2 = gds.FloatItem("x1+x2").set_prop("display", active=False)
+    color = gds.ColorItem("Color", default="red").set_prop(
+        "display", callback=cb_example
+    )
+
+    def choices_callback(self, item, value):
+        """Choices callback: this demonstrates how to dynamically change
+        the list of choices... even if it is not very useful in this case
+
+        Note that `None` is systematically added as the third element of
+        the returned tuples: that is to ensure the compatibility between
+        `ChoiceItem` and `ImageChoiceItem` (see `guidata.dataset.dataitems`)
+        """
+        execenv.print(f"[choices_callback]: item={item}, value={value}")
+        return [
+            (16, "first choice", None),
+            (32, "second choice", None),
+            (64, "third choice", None),
+        ]
+
+    choice = (
+        gds.ChoiceItem(
+            "Single choice",
+            choices_callback,
+            default=64,
+        )
+        .set_pos(col=1, colspan=2)
+        .set_prop("display", callback=cb_example)
+    )
+    results = gds.TextItem("Results")
+
+
+def test_callbacks():
+    """Test callbacks"""
+    with qt_app_context():
+        prm = Parameters()
+        execenv.print(prm)
+        if prm.edit():
+            execenv.print(prm)
+        prm.view()
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_callbacks()
diff --git a/guidata/tests/test_datasetgroup.py b/guidata/tests/dataset/test_datasetgroup.py
similarity index 89%
rename from guidata/tests/test_datasetgroup.py
rename to guidata/tests/dataset/test_datasetgroup.py
index 53d715d..2a1f317 100644
--- a/guidata/tests/test_datasetgroup.py
+++ b/guidata/tests/dataset/test_datasetgroup.py
@@ -1,34 +1,34 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-DataSetGroup demo
-
-DataSet objects may be grouped into DataSetGroup, allowing them to be edited
-in a single dialog box (with one tab per DataSet object).
-"""
-
-# guitest: show
-
-from guidata.dataset import DataSetGroup
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context
-from guidata.tests.test_all_features import Parameters
-
-
-def test_dataset_group():
-    """Test DataSetGroup"""
-    with qt_app_context():
-        e1 = Parameters("DataSet #1")
-        e2 = Parameters("DataSet #2")
-        g = DataSetGroup([e1, e2], title="Parameters group")
-        g.edit()
-        execenv.print(e1)
-        g.edit()
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_dataset_group()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+DataSetGroup demo
+
+DataSet objects may be grouped into DataSetGroup, allowing them to be edited
+in a single dialog box (with one tab per DataSet object).
+"""
+
+# guitest: show
+
+from guidata.dataset import DataSetGroup
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context
+from guidata.tests.dataset.test_all_features import Parameters
+
+
+def test_dataset_group():
+    """Test DataSetGroup"""
+    with qt_app_context():
+        e1 = Parameters("DataSet #1")
+        e2 = Parameters("DataSet #2")
+        g = DataSetGroup([e1, e2], title="Parameters group")
+        g.edit()
+        execenv.print(e1)
+        g.edit()
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_dataset_group()
diff --git a/guidata/tests/test_editgroupbox.py b/guidata/tests/dataset/test_editgroupbox.py
similarity index 98%
rename from guidata/tests/test_editgroupbox.py
rename to guidata/tests/dataset/test_editgroupbox.py
index 6c63941..afc3fd7 100644
--- a/guidata/tests/test_editgroupbox.py
+++ b/guidata/tests/dataset/test_editgroupbox.py
@@ -26,7 +26,7 @@
     qt_app_context,
     win32_fix_title_bar_background,
 )
-from guidata.tests.test_activable_dataset import Parameters
+from guidata.tests.dataset.test_activable_dataset import Parameters
 from guidata.widgets import about
 
 
diff --git a/guidata/tests/test_inheritance.py b/guidata/tests/dataset/test_inheritance.py
similarity index 96%
rename from guidata/tests/test_inheritance.py
rename to guidata/tests/dataset/test_inheritance.py
index 060949f..3bc38d1 100644
--- a/guidata/tests/test_inheritance.py
+++ b/guidata/tests/dataset/test_inheritance.py
@@ -1,54 +1,54 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-DataSet objects inheritance test
-
-From time to time, it may be useful to derive a DataSet from another. The main
-application is to extend a parameter set with additionnal parameters.
-"""
-
-# guitest: show
-
-import guidata.dataset as gds
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context
-
-
-class OriginalDataset(gds.DataSet):
-    """Original dataset
-    This is the original dataset"""
-
-    bool = gds.BoolItem("Boolean")
-    string = gds.StringItem("String")
-    text = gds.TextItem("Text")
-    float = gds.FloatItem("Float", default=0.5, min=0, max=1, step=0.01, slider=True)
-
-
-class DerivedDataset(OriginalDataset):
-    """Derived dataset
-    This is the derived dataset"""
-
-    bool = gds.BoolItem("Boolean (modified in derived dataset)")
-    a = gds.FloatItem("Level 1 (added in derived dataset)", default=0)
-    b = gds.FloatItem("Level 2 (added in derived dataset)", default=0)
-    c = gds.FloatItem("Level 3 (added in derived dataset)", default=0)
-
-
-def test_inheritance():
-    """Test DataSet inheritance"""
-    with qt_app_context():
-        e = OriginalDataset()
-        e.edit()
-        execenv.print(e)
-
-        e = DerivedDataset()
-        e.edit()
-        execenv.print(e)
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_inheritance()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+DataSet objects inheritance test
+
+From time to time, it may be useful to derive a DataSet from another. The main
+application is to extend a parameter set with additionnal parameters.
+"""
+
+# guitest: show
+
+import guidata.dataset as gds
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context
+
+
+class OriginalDataset(gds.DataSet):
+    """Original dataset
+    This is the original dataset"""
+
+    bool = gds.BoolItem("Boolean")
+    string = gds.StringItem("String")
+    text = gds.TextItem("Text")
+    float = gds.FloatItem("Float", default=0.5, min=0, max=1, step=0.01, slider=True)
+
+
+class DerivedDataset(OriginalDataset):
+    """Derived dataset
+    This is the derived dataset"""
+
+    bool = gds.BoolItem("Boolean (modified in derived dataset)")
+    a = gds.FloatItem("Level 1 (added in derived dataset)", default=0)
+    b = gds.FloatItem("Level 2 (added in derived dataset)", default=0)
+    c = gds.FloatItem("Level 3 (added in derived dataset)", default=0)
+
+
+def test_inheritance():
+    """Test DataSet inheritance"""
+    with qt_app_context():
+        e = OriginalDataset()
+        e.edit()
+        execenv.print(e)
+
+        e = DerivedDataset()
+        e.edit()
+        execenv.print(e)
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_inheritance()
diff --git a/guidata/tests/test_item_order.py b/guidata/tests/dataset/test_item_order.py
similarity index 100%
rename from guidata/tests/test_item_order.py
rename to guidata/tests/dataset/test_item_order.py
diff --git a/guidata/tests/test_loadsave_hdf5.py b/guidata/tests/dataset/test_loadsave_hdf5.py
similarity index 94%
rename from guidata/tests/test_loadsave_hdf5.py
rename to guidata/tests/dataset/test_loadsave_hdf5.py
index 76dd399..5afa6d0 100644
--- a/guidata/tests/test_loadsave_hdf5.py
+++ b/guidata/tests/dataset/test_loadsave_hdf5.py
@@ -18,7 +18,7 @@
 from guidata.dataset.io import HDF5Reader, HDF5Writer
 from guidata.env import execenv
 from guidata.qthelpers import qt_app_context
-from guidata.tests.test_all_items import Parameters
+from guidata.tests.dataset.test_all_items import Parameters
 
 
 def test_loadsave_hdf5():
diff --git a/guidata/tests/test_loadsave_json.py b/guidata/tests/dataset/test_loadsave_json.py
similarity index 94%
rename from guidata/tests/test_loadsave_json.py
rename to guidata/tests/dataset/test_loadsave_json.py
index cf87582..a806ffa 100644
--- a/guidata/tests/test_loadsave_json.py
+++ b/guidata/tests/dataset/test_loadsave_json.py
@@ -17,7 +17,7 @@
 from guidata.dataset.io import JSONReader, JSONWriter
 from guidata.env import execenv
 from guidata.qthelpers import qt_app_context
-from guidata.tests.test_all_items import Parameters
+from guidata.tests.dataset.test_all_items import Parameters
 
 
 def test_loadsave_json():
diff --git a/guidata/tests/test_rotatedlabel.py b/guidata/tests/dataset/test_rotatedlabel.py
similarity index 96%
rename from guidata/tests/test_rotatedlabel.py
rename to guidata/tests/dataset/test_rotatedlabel.py
index 82b89c1..366ae72 100644
--- a/guidata/tests/test_rotatedlabel.py
+++ b/guidata/tests/dataset/test_rotatedlabel.py
@@ -1,53 +1,53 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-RotatedLabel test
-
-RotatedLabel is derived from QLabel: it provides rotated text display.
-"""
-
-# guitest: show
-
-from qtpy.QtCore import Qt
-from qtpy.QtWidgets import QFrame, QGridLayout
-
-from guidata.env import execenv
-from guidata.qthelpers import qt_app_context, win32_fix_title_bar_background
-from guidata.widgets.rotatedlabel import RotatedLabel
-
-
-class Frame(QFrame):
-    """Test frame"""
-
-    def __init__(self, parent=None):
-        QFrame.__init__(self, parent)
-        win32_fix_title_bar_background(self)
-        layout = QGridLayout()
-        self.setLayout(layout)
-        angle = 0
-        for row in range(7):
-            for column in range(7):
-                layout.addWidget(
-                    RotatedLabel(
-                        "Label %03d°" % angle, angle=angle, color=Qt.blue, bold=True
-                    ),
-                    row,
-                    column,
-                    Qt.AlignCenter,
-                )
-                angle += 10
-
-
-def test_rotatedlabel():
-    """Test RotatedLabel"""
-    with qt_app_context(exec_loop=True):
-        frame = Frame()
-        frame.show()
-        execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_rotatedlabel()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+RotatedLabel test
+
+RotatedLabel is derived from QLabel: it provides rotated text display.
+"""
+
+# guitest: show
+
+from qtpy.QtCore import Qt
+from qtpy.QtWidgets import QFrame, QGridLayout
+
+from guidata.env import execenv
+from guidata.qthelpers import qt_app_context, win32_fix_title_bar_background
+from guidata.widgets.rotatedlabel import RotatedLabel
+
+
+class Frame(QFrame):
+    """Test frame"""
+
+    def __init__(self, parent=None):
+        QFrame.__init__(self, parent)
+        win32_fix_title_bar_background(self)
+        layout = QGridLayout()
+        self.setLayout(layout)
+        angle = 0
+        for row in range(7):
+            for column in range(7):
+                layout.addWidget(
+                    RotatedLabel(
+                        "Label %03d°" % angle, angle=angle, color=Qt.blue, bold=True
+                    ),
+                    row,
+                    column,
+                    Qt.AlignCenter,
+                )
+                angle += 10
+
+
+def test_rotatedlabel():
+    """Test RotatedLabel"""
+    with qt_app_context(exec_loop=True):
+        frame = Frame()
+        frame.show()
+        execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_rotatedlabel()
diff --git a/guidata/tests/unit/__init__.py b/guidata/tests/unit/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/guidata/tests/test_config.py b/guidata/tests/unit/test_config.py
similarity index 90%
rename from guidata/tests/test_config.py
rename to guidata/tests/unit/test_config.py
index b9b55eb..70ee13c 100644
--- a/guidata/tests/test_config.py
+++ b/guidata/tests/unit/test_config.py
@@ -1,48 +1,48 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""Config test"""
-
-import pytest
-
-from guidata.config import UserConfig
-from guidata.tests.test_all_features import Parameters
-
-
-@pytest.fixture()
-def config():
-    """Create a config object"""
-    CONF = UserConfig({})
-    eta = Parameters()
-    eta.write_config(CONF, "TestParameters", "")
-    yield CONF
-
-
-def test_load(config):
-    """Test load config"""
-    eta = Parameters()
-    eta.read_config(config, "TestParameters", "")
-
-
-def test_default(config):
-    """Test default config"""
-    eta = Parameters()
-    eta.write_config(config, "etagere2", "")
-    eta = Parameters()
-    eta.read_config(config, "etagere2", "")
-
-
-def test_restore(config):
-    """Test restore config"""
-    eta = Parameters()
-    eta.fl2 = 2
-    eta.integer = 6
-    eta.write_config(config, "etagere3", "")
-
-    eta = Parameters()
-    eta.read_config(config, "etagere3", "")
-
-    assert eta.fl2 == 2.0
-    assert eta.integer == 6
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""Config test"""
+
+import pytest
+
+from guidata.config import UserConfig
+from guidata.tests.dataset.test_all_features import Parameters
+
+
+@pytest.fixture()
+def config():
+    """Create a config object"""
+    CONF = UserConfig({})
+    eta = Parameters()
+    eta.write_config(CONF, "TestParameters", "")
+    yield CONF
+
+
+def test_load(config):
+    """Test load config"""
+    eta = Parameters()
+    eta.read_config(config, "TestParameters", "")
+
+
+def test_default(config):
+    """Test default config"""
+    eta = Parameters()
+    eta.write_config(config, "etagere2", "")
+    eta = Parameters()
+    eta.read_config(config, "etagere2", "")
+
+
+def test_restore(config):
+    """Test restore config"""
+    eta = Parameters()
+    eta.fl2 = 2
+    eta.integer = 6
+    eta.write_config(config, "etagere3", "")
+
+    eta = Parameters()
+    eta.read_config(config, "etagere3", "")
+
+    assert eta.fl2 == 2.0
+    assert eta.integer == 6
diff --git a/guidata/tests/test_data.py b/guidata/tests/unit/test_data.py
similarity index 96%
rename from guidata/tests/test_data.py
rename to guidata/tests/unit/test_data.py
index aebf3aa..4c11ceb 100644
--- a/guidata/tests/test_data.py
+++ b/guidata/tests/unit/test_data.py
@@ -1,53 +1,53 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""Unit tests"""
-
-
-import unittest
-
-import guidata.dataset as gds
-from guidata.dataset.conv import update_dataset
-from guidata.env import execenv
-
-
-class Parameters(gds.DataSet):
-    """Example dataset"""
-
-    float1 = gds.FloatItem("float #1", min=1, max=250, help="height in cm")
-    float2 = gds.FloatItem("float #2", min=1, max=250, help="width in cm")
-    number = gds.IntItem("number", min=3, max=20)
-
-
-class TestCheck(unittest.TestCase):
-    def test_range(self):
-        """Test range checking of FloatItem"""
-        e = Parameters()
-        e.float1 = 150.0
-        e.float2 = 400.0
-        e.number = 4
-        errors = e.check()
-        self.assertEqual(errors, ["float2"])
-
-    def test_typechecking(self):
-        """Test type checking of FloatItem"""
-        e = Parameters()
-        e.float1 = 150
-        e.float2 = 400
-        e.number = 4.0
-        errors = e.check()
-        self.assertEqual(errors, ["float1", "float2", "number"])
-
-    def test_update(self):
-        e1 = Parameters()
-        e2 = Parameters()
-        e1.float1 = 23
-        update_dataset(e2, e1)
-        self.assertEqual(e2.float1, 23)
-
-
-if __name__ == "__main__":
-    unittest.main()
-    execenv.print("OK")
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""Unit tests"""
+
+
+import unittest
+
+import guidata.dataset as gds
+from guidata.dataset.conv import update_dataset
+from guidata.env import execenv
+
+
+class Parameters(gds.DataSet):
+    """Example dataset"""
+
+    float1 = gds.FloatItem("float #1", min=1, max=250, help="height in cm")
+    float2 = gds.FloatItem("float #2", min=1, max=250, help="width in cm")
+    number = gds.IntItem("number", min=3, max=20)
+
+
+class TestCheck(unittest.TestCase):
+    def test_range(self):
+        """Test range checking of FloatItem"""
+        e = Parameters()
+        e.float1 = 150.0
+        e.float2 = 400.0
+        e.number = 4
+        errors = e.check()
+        self.assertEqual(errors, ["float2"])
+
+    def test_typechecking(self):
+        """Test type checking of FloatItem"""
+        e = Parameters()
+        e.float1 = 150
+        e.float2 = 400
+        e.number = 4.0
+        errors = e.check()
+        self.assertEqual(errors, ["float1", "float2", "number"])
+
+    def test_update(self):
+        e1 = Parameters()
+        e2 = Parameters()
+        e1.float1 = 23
+        update_dataset(e2, e1)
+        self.assertEqual(e2.float1, 23)
+
+
+if __name__ == "__main__":
+    unittest.main()
+    execenv.print("OK")
diff --git a/guidata/tests/test_dataset_from_dict.py b/guidata/tests/unit/test_dataset_from_dict.py
similarity index 100%
rename from guidata/tests/test_dataset_from_dict.py
rename to guidata/tests/unit/test_dataset_from_dict.py
diff --git a/guidata/tests/test_dataset_from_func.py b/guidata/tests/unit/test_dataset_from_func.py
similarity index 100%
rename from guidata/tests/test_dataset_from_func.py
rename to guidata/tests/unit/test_dataset_from_func.py
diff --git a/guidata/tests/test_disthelpers.py b/guidata/tests/unit/test_disthelpers.py
similarity index 95%
rename from guidata/tests/test_disthelpers.py
rename to guidata/tests/unit/test_disthelpers.py
index 582e4ac..812dae3 100644
--- a/guidata/tests/test_disthelpers.py
+++ b/guidata/tests/unit/test_disthelpers.py
@@ -1,40 +1,40 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""
-guidata.disthelpers demo
-
-How to create an executable with py2exe or cx_Freeze with less efforts than
-writing a complete setup script.
-"""
-
-# guitest: show
-
-import os.path as osp
-
-import pytest
-
-from guidata.env import execenv
-from guidata.utils.disthelpers import Distribution
-
-
-@pytest.mark.skip(reason="Currently not supporting Python > 3.6")
-def test_disthelpers():
-    """Test disthelpers"""
-    dist = Distribution()
-    dist.setup(
-        name="Application demo",
-        version="1.0.0",
-        description="Application demo based on editgroupbox.py",
-        script=osp.join(osp.dirname(__file__), "test_editgroupbox.py"),
-        target_name="demo.exe",
-    )
-    dist.add_modules("guidata")
-    dist.build("cx_Freeze")
-    execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_disthelpers()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+guidata.disthelpers demo
+
+How to create an executable with py2exe or cx_Freeze with less efforts than
+writing a complete setup script.
+"""
+
+# guitest: show
+
+import os.path as osp
+
+import pytest
+
+from guidata.env import execenv
+from guidata.utils.disthelpers import Distribution
+
+
+@pytest.mark.skip(reason="Currently not supporting Python > 3.6")
+def test_disthelpers():
+    """Test disthelpers"""
+    dist = Distribution()
+    dist.setup(
+        name="Application demo",
+        version="1.0.0",
+        description="Application demo based on editgroupbox.py",
+        script=osp.join(osp.dirname(__file__), "test_editgroupbox.py"),
+        target_name="demo.exe",
+    )
+    dist.add_modules("guidata")
+    dist.build("cx_Freeze")
+    execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_disthelpers()
diff --git a/guidata/tests/test_genreqs.py b/guidata/tests/unit/test_genreqs.py
similarity index 100%
rename from guidata/tests/test_genreqs.py
rename to guidata/tests/unit/test_genreqs.py
diff --git a/guidata/tests/test_no_qt.py b/guidata/tests/unit/test_no_qt.py
similarity index 100%
rename from guidata/tests/test_no_qt.py
rename to guidata/tests/unit/test_no_qt.py
diff --git a/guidata/tests/test_text.py b/guidata/tests/unit/test_text.py
similarity index 100%
rename from guidata/tests/test_text.py
rename to guidata/tests/unit/test_text.py
diff --git a/guidata/tests/test_translations.py b/guidata/tests/unit/test_translations.py
similarity index 95%
rename from guidata/tests/test_translations.py
rename to guidata/tests/unit/test_translations.py
index a785acc..ae4cd38 100644
--- a/guidata/tests/test_translations.py
+++ b/guidata/tests/unit/test_translations.py
@@ -1,24 +1,24 @@
-# -*- coding: utf-8 -*-
-#
-# Licensed under the terms of the BSD 3-Clause
-# (see guidata/LICENSE for details)
-
-"""Little translation test"""
-
-# guitest: show
-
-from guidata.config import _
-from guidata.env import execenv
-
-translations = (_("Some required entries are incorrect"),)
-
-
-def test_translations():
-    """Test translations"""
-    for text in translations:
-        execenv.print(text)
-    execenv.print("OK")
-
-
-if __name__ == "__main__":
-    test_translations()
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""Little translation test"""
+
+# guitest: show
+
+from guidata.config import _
+from guidata.env import execenv
+
+translations = (_("Some required entries are incorrect"),)
+
+
+def test_translations():
+    """Test translations"""
+    for text in translations:
+        execenv.print(text)
+    execenv.print("OK")
+
+
+if __name__ == "__main__":
+    test_translations()
diff --git a/guidata/tests/test_updaterestoredataset.py b/guidata/tests/unit/test_updaterestoredataset.py
similarity index 97%
rename from guidata/tests/test_updaterestoredataset.py
rename to guidata/tests/unit/test_updaterestoredataset.py
index 34a4f31..827bdca 100644
--- a/guidata/tests/test_updaterestoredataset.py
+++ b/guidata/tests/unit/test_updaterestoredataset.py
@@ -12,7 +12,7 @@
 import numpy as np
 
 from guidata.dataset.conv import restore_dataset, update_dataset
-from guidata.tests.test_all_items import Parameters
+from guidata.tests.dataset.test_all_items import Parameters
 
 
 def test_update_restore_dataset():
diff --git a/guidata/tests/test_userconfig_app.py b/guidata/tests/unit/test_userconfig_app.py
similarity index 100%
rename from guidata/tests/test_userconfig_app.py
rename to guidata/tests/unit/test_userconfig_app.py
diff --git a/guidata/tests/widgets/__init__.py b/guidata/tests/widgets/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/guidata/tests/test_arrayeditor.py b/guidata/tests/widgets/test_arrayeditor.py
similarity index 100%
rename from guidata/tests/test_arrayeditor.py
rename to guidata/tests/widgets/test_arrayeditor.py
diff --git a/guidata/tests/test_codeeditor.py b/guidata/tests/widgets/test_codeeditor.py
similarity index 81%
rename from guidata/tests/test_codeeditor.py
rename to guidata/tests/widgets/test_codeeditor.py
index 8ada11d..d52d4b2 100644
--- a/guidata/tests/test_codeeditor.py
+++ b/guidata/tests/widgets/test_codeeditor.py
@@ -10,6 +10,7 @@
 
 # guitest: show
 
+from guidata.configtools import get_icon
 from guidata.env import execenv
 from guidata.qthelpers import qt_app_context
 from guidata.widgets import codeeditor
@@ -21,6 +22,8 @@ def test_codeeditor():
         widget = codeeditor.CodeEditor(language="python")
         widget.set_text_from_file(codeeditor.__file__)
         widget.resize(800, 600)
+        widget.setWindowTitle("Code editor")
+        widget.setWindowIcon(get_icon("guidata.svg"))
         widget.show()
         execenv.print("OK")
 
diff --git a/guidata/tests/test_collectionseditor.py b/guidata/tests/widgets/test_collectionseditor.py
similarity index 100%
rename from guidata/tests/test_collectionseditor.py
rename to guidata/tests/widgets/test_collectionseditor.py
diff --git a/guidata/tests/test_console.py b/guidata/tests/widgets/test_console.py
similarity index 80%
rename from guidata/tests/test_console.py
rename to guidata/tests/widgets/test_console.py
index ddf3da2..5088958 100644
--- a/guidata/tests/test_console.py
+++ b/guidata/tests/widgets/test_console.py
@@ -10,6 +10,7 @@
 
 # guitest: show
 
+from guidata.configtools import get_icon
 from guidata.env import execenv
 from guidata.qthelpers import qt_app_context
 from guidata.widgets.console import Console
@@ -20,6 +21,8 @@ def test_console():
     with qt_app_context(exec_loop=True):
         widget = Console(debug=False, multithreaded=True)
         widget.resize(800, 600)
+        widget.setWindowTitle("Console")
+        widget.setWindowIcon(get_icon("guidata.svg"))
         widget.show()
         execenv.print("OK")
 
diff --git a/guidata/tests/test_dataframeeditor.py b/guidata/tests/widgets/test_dataframeeditor.py
similarity index 100%
rename from guidata/tests/test_dataframeeditor.py
rename to guidata/tests/widgets/test_dataframeeditor.py
diff --git a/guidata/tests/test_importwizard.py b/guidata/tests/widgets/test_importwizard.py
similarity index 100%
rename from guidata/tests/test_importwizard.py
rename to guidata/tests/widgets/test_importwizard.py
diff --git a/guidata/tests/test_objecteditor.py b/guidata/tests/widgets/test_objecteditor.py
similarity index 100%
rename from guidata/tests/test_objecteditor.py
rename to guidata/tests/widgets/test_objecteditor.py