diff --git a/.coveragerc b/.coveragerc
new file mode 100644
index 000000000..d16dd221a
--- /dev/null
+++ b/.coveragerc
@@ -0,0 +1,9 @@
+[run]
+omit =
+
+[report]
+exclude_lines =
+    pragma: no cover
+    if TYPE_CHECKING:
+    if __name__ == "__main__":
+    @overload
diff --git a/src/textual/_loop.py b/src/textual/_loop.py
index 01c6cafbe..7a057fc21 100644
--- a/src/textual/_loop.py
+++ b/src/textual/_loop.py
@@ -1,9 +1,11 @@
-from typing import Iterable, Tuple, TypeVar
+from __future__ import annotations
+
+from typing import Iterable, TypeVar
 
 T = TypeVar("T")
 
 
-def loop_first(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
+def loop_first(values: Iterable[T]) -> Iterable[tuple[bool, T]]:
     """Iterate and generate a tuple with a flag for first value."""
     iter_values = iter(values)
     try:
@@ -15,7 +17,7 @@ def loop_first(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
         yield False, value
 
 
-def loop_last(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
+def loop_last(values: Iterable[T]) -> Iterable[tuple[bool, T]]:
     """Iterate and generate a tuple with a flag for last value."""
     iter_values = iter(values)
     try:
@@ -28,7 +30,7 @@ def loop_last(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
     yield True, previous_value
 
 
-def loop_first_last(values: Iterable[T]) -> Iterable[Tuple[bool, bool, T]]:
+def loop_first_last(values: Iterable[T]) -> Iterable[tuple[bool, bool, T]]:
     """Iterate and generate a tuple with a flag for first and last value."""
     iter_values = iter(values)
     try:
diff --git a/src/textual/scrollbar.py b/src/textual/scrollbar.py
index 0dfba622b..62b5c3726 100644
--- a/src/textual/scrollbar.py
+++ b/src/textual/scrollbar.py
@@ -14,27 +14,26 @@ from .widget import Reactive, Widget
 
 
 @rich.repr.auto
-class ScrollUp(Message, bubble=True):
+class ScrollUp(Message):
     """Message sent when clicking above handle."""
 
 
 @rich.repr.auto
-class ScrollDown(Message, bubble=True):
+class ScrollDown(Message):
     """Message sent when clicking below handle."""
 
 
 @rich.repr.auto
-class ScrollLeft(Message, bubble=True):
+class ScrollLeft(Message):
     """Message sent when clicking above handle."""
 
 
 @rich.repr.auto
-class ScrollRight(Message, bubble=True):
+class ScrollRight(Message):
     """Message sent when clicking below handle."""
 
 
-@rich.repr.auto
-class ScrollTo(Message, bubble=True):
+class ScrollTo(Message):
     """Message sent when click and dragging handle."""
 
     def __init__(
diff --git a/tests/test_case.py b/tests/test_case.py
new file mode 100644
index 000000000..dbc7b94b2
--- /dev/null
+++ b/tests/test_case.py
@@ -0,0 +1,5 @@
+from textual.case import camel_to_snake
+
+
+def test_camel_to_snake():
+    assert camel_to_snake("FooBar") == "foo_bar"
diff --git a/tests/test_loop.py b/tests/test_loop.py
new file mode 100644
index 000000000..c235f23a5
--- /dev/null
+++ b/tests/test_loop.py
@@ -0,0 +1,28 @@
+from textual._loop import loop_first, loop_last, loop_first_last
+
+
+def test_loop_first():
+    assert list(loop_first([])) == []
+    iterable = loop_first(["apples", "oranges", "pears", "lemons"])
+    assert next(iterable) == (True, "apples")
+    assert next(iterable) == (False, "oranges")
+    assert next(iterable) == (False, "pears")
+    assert next(iterable) == (False, "lemons")
+
+
+def test_loop_last():
+    assert list(loop_last([])) == []
+    iterable = loop_last(["apples", "oranges", "pears", "lemons"])
+    assert next(iterable) == (False, "apples")
+    assert next(iterable) == (False, "oranges")
+    assert next(iterable) == (False, "pears")
+    assert next(iterable) == (True, "lemons")
+
+
+def test_loop_first_last():
+    assert list(loop_first_last([])) == []
+    iterable = loop_first_last(["apples", "oranges", "pears", "lemons"])
+    assert next(iterable) == (True, False, "apples")
+    assert next(iterable) == (False, False, "oranges")
+    assert next(iterable) == (False, False, "pears")
+    assert next(iterable) == (False, True, "lemons")