diff --git a/brainglobe_utils/qtpy/dialog.py b/brainglobe_utils/qtpy/dialog.py
index 9ba3cde..ad4fe6c 100644
--- a/brainglobe_utils/qtpy/dialog.py
+++ b/brainglobe_utils/qtpy/dialog.py
@@ -17,7 +17,7 @@ def display_warning(widget: QWidget, title: str, message: str) -> bool:
         return False
 
 
-def display_info(widget, title, message):
+def display_info(widget: QWidget, title: str, message: str):
     """
     Display information in a pop-up that can only be accepted
     """
diff --git a/brainglobe_utils/qtpy/interaction.py b/brainglobe_utils/qtpy/interaction.py
index a5ac1d8..0da8f62 100644
--- a/brainglobe_utils/qtpy/interaction.py
+++ b/brainglobe_utils/qtpy/interaction.py
@@ -46,8 +46,16 @@ def add_button(
 
 
 def add_checkbox(
-    layout, default, label, row: int = 0, column: int = 0, tooltip=None
-):
+    layout: QLayout,
+    default: bool,
+    label: str,
+    row: int = 0,
+    column: int = 0,
+    tooltip: Optional[str] = None,
+) -> QCheckBox:
+    """
+    Add a checkbox to *layout*.
+    """
     box = QCheckBox()
     box.setChecked(default)
     if tooltip:
@@ -58,16 +66,19 @@ def add_checkbox(
 
 
 def add_float_box(
-    layout,
-    default,
-    minimum,
-    maximum,
-    label,
-    step,
+    layout: QLayout,
+    default: float,
+    minimum: float,
+    maximum: float,
+    label: str,
+    step: float,
     row: int = 0,
     column: int = 0,
-    tooltip=None,
-):
+    tooltip: Optional[str] = None,
+) -> QDoubleSpinBox:
+    """
+    Add a spin box for float values to *layout*.
+    """
     box = QDoubleSpinBox()
     box.setMinimum(minimum)
     box.setMaximum(maximum)
@@ -81,15 +92,18 @@ def add_float_box(
 
 
 def add_int_box(
-    layout,
-    default,
-    minimum,
-    maximum,
-    label,
+    layout: QLayout,
+    default: int,
+    minimum: int,
+    maximum: int,
+    label: str,
     row: int = 0,
     column: int = 0,
-    tooltip=None,
-):
+    tooltip: Optional[str] = None,
+) -> QSpinBox:
+    """
+    Add a spin box for integer values to *layout*.
+    """
     box = QSpinBox()
     box.setMinimum(minimum)
     box.setMaximum(maximum)
@@ -109,7 +123,7 @@ def add_combobox(
     row: int = 0,
     column: int = 0,
     label_stack: bool = False,
-    callback=None,
+    callback: Optional[Callable] = None,
     width: int = 150,
 ) -> Tuple[QComboBox, Optional[QLabel]]:
     """
diff --git a/tests/tests/test_qtpy/test_dialog.py b/tests/tests/test_qtpy/test_dialog.py
new file mode 100644
index 0000000..de46c0c
--- /dev/null
+++ b/tests/tests/test_qtpy/test_dialog.py
@@ -0,0 +1,27 @@
+import pytest
+from qtpy.QtWidgets import QGroupBox, QMessageBox
+
+from brainglobe_utils.qtpy.dialog import display_warning
+
+
+@pytest.mark.parametrize(
+    "messagebox_return",
+    [QMessageBox.Yes, QMessageBox.Cancel],
+    ids=["Yes", "Cancel"],
+)
+def test_display_warning(qtbot, monkeypatch, messagebox_return):
+    """
+    Test display_warning returns True/False when accepted/cancelled.
+    """
+    # Use monkeypatch to return a set value from the modal dialog.
+    monkeypatch.setattr(
+        QMessageBox, "question", lambda *args: messagebox_return
+    )
+
+    box = QGroupBox()
+    qtbot.addWidget(box)
+    response = display_warning(box, "warning", "an example message")
+    if messagebox_return == QMessageBox.Yes:
+        assert response is True
+    else:
+        assert response is False
diff --git a/tests/tests/test_qtpy/test_interaction.py b/tests/tests/test_qtpy/test_interaction.py
index 68fd1f3..aa69299 100644
--- a/tests/tests/test_qtpy/test_interaction.py
+++ b/tests/tests/test_qtpy/test_interaction.py
@@ -1,39 +1,170 @@
 import pytest
-from qtpy.QtWidgets import QGridLayout
+from qtpy.QtWidgets import QGridLayout, QGroupBox
 
-from brainglobe_utils.qtpy.interaction import add_button, add_combobox
+from brainglobe_utils.qtpy.interaction import (
+    add_button,
+    add_checkbox,
+    add_combobox,
+    add_float_box,
+    add_int_box,
+)
+
+
+@pytest.fixture()
+def box() -> QGroupBox:
+    """
+    Return a QGroupBox with a grid layout.
+    """
+    box = QGroupBox()
+    layout = QGridLayout()
+    box.setLayout(layout)
+
+    return box
 
 
 @pytest.mark.parametrize("label_stack", [True, False])
 @pytest.mark.parametrize("label", ["A label", None])
-def test_add_combobox(label, label_stack):
+def test_add_combobox(qtbot, box, label, label_stack):
     """
-    Smoke test for add_combobox for all conditional branches
+    Smoke test for add_combobox. Tests if a combobox can be added to a layout
+    with/without a label, and with/without label_stack.
     """
-    layout = QGridLayout()
+    qtbot.addWidget(box)
+    layout = box.layout()
+    items = ["item 1", "item 2"]
+
+    # callback function for whenever the current index of the combobox changes
+    def callback():
+        pass
+
+    # returns tuple of (combobox, combobox_label)
     combobox = add_combobox(
         layout,
         row=0,
         label=label,
-        items=["item 1", "item 2"],
+        items=items,
         label_stack=label_stack,
+        callback=callback,
     )
+
     assert combobox is not None
+    assert combobox[0].count() == len(items)
 
+    if label is None:
+        assert combobox[1] is None
+        assert layout.count() == 1
+    else:
+        assert combobox[1].text() == label
+        assert layout.count() == 2
 
-@pytest.mark.parametrize(
-    argnames="alignment", argvalues=["center", "left", "right"]
-)
-def test_add_button(alignment):
+
+@pytest.mark.parametrize("alignment", ["center", "left", "right"])
+def test_add_button(qtbot, box, alignment):
     """
-    Smoke tests for add_button for all conditional branches
+    Smoke test for add_button. Tests if a button can be added to a layout with
+    the correct label/tooltip using different alignments.
     """
-    layout = QGridLayout()
+    qtbot.addWidget(box)
+    layout = box.layout()
+    label = "A button"
+    tooltip = "A useful tooltip"
+
     button = add_button(
         layout=layout,
         connected_function=lambda: None,
-        label="A button",
+        label=label,
         row=0,
         alignment=alignment,
+        tooltip=tooltip,
     )
+
     assert button is not None
+    assert layout.count() == 1
+    assert button.text() == label
+    assert button.toolTip() == tooltip
+
+
+def test_add_checkbox(qtbot, box):
+    """
+    Smoke test for add_checkbox. Tests if a checkbox can be added to a layout
+    with the correct label/tooltip.
+    """
+    qtbot.addWidget(box)
+    layout = box.layout()
+    label = "A checkbox"
+    tooltip = "A useful tooltip"
+
+    checkbox = add_checkbox(
+        layout=layout, default=True, label=label, tooltip=tooltip
+    )
+
+    assert checkbox is not None
+    # layout should contain 2 items: QLabel and QCheckbox
+    assert layout.count() == 2
+    assert layout.itemAt(0).widget().text() == label
+    assert checkbox.toolTip() == tooltip
+
+
+def test_add_float_box(qtbot, box):
+    """
+    Smoke test for add_float_box. Tests if a float spinbox can be added to a
+    layout with the correct label, tooltip, minimum, maximum and default value.
+    """
+    qtbot.addWidget(box)
+    layout = box.layout()
+    label = "A float box"
+    tooltip = "A useful tooltip"
+    default = 0.5
+    minimum = 0.0
+    maximum = 1.0
+
+    floatbox = add_float_box(
+        layout=layout,
+        default=default,
+        minimum=minimum,
+        maximum=maximum,
+        label=label,
+        step=0.1,
+        tooltip=tooltip,
+    )
+
+    assert floatbox is not None
+    # layout should contain 2 items: QLabel and QDoubleSpinBox
+    assert layout.count() == 2
+    assert layout.itemAt(0).widget().text() == label
+    assert floatbox.maximum() == maximum
+    assert floatbox.minimum() == minimum
+    assert floatbox.value() == default
+    assert floatbox.toolTip() == tooltip
+
+
+def test_add_int_box(qtbot, box):
+    """
+    Smoke test for add_int_box. Tests if an int spinbox can be added to a
+    layout with the correct label, tooltip, minimum, maximum and default value.
+    """
+    qtbot.addWidget(box)
+    layout = box.layout()
+    label = "An int box"
+    tooltip = "A useful tooltip"
+    default = 5
+    minimum = 0
+    maximum = 10
+
+    intbox = add_int_box(
+        layout=layout,
+        default=default,
+        minimum=minimum,
+        maximum=maximum,
+        label=label,
+        tooltip=tooltip,
+    )
+
+    assert intbox is not None
+    # layout should contain 2 items: QLabel and QSpinBox
+    assert layout.count() == 2
+    assert layout.itemAt(0).widget().text() == label
+    assert intbox.maximum() == maximum
+    assert intbox.minimum() == minimum
+    assert intbox.value() == default
+    assert intbox.toolTip() == tooltip