feat(core/geometry): add validation on Box to check for valid margin/…

…border/padding

src/qtile_bonsai/core/geometry.py

@@ -275,6 +275,10 @@ def __init__(
         self.border = border
         self.padding = padding
 
+        # TODO: Want to invoke this here, but need to redo how tab bars are hidden. The
+        # logic currently relies on being able to set `height = 0`.
+        # self.validate()
+
     @property
     def principal_rect(self) -> Rect:
         return self._principal_rect
@@ -365,6 +369,13 @@ def content_rect(self) -> Rect:
             h=padding_rect.h - (padding.top + padding.bottom),
         )
 
+    def validate(self):
+        content_rect = self.content_rect
+        if content_rect.w <= 0 or content_rect.h <= 0:
+            raise ValueError(
+                "Invalid margin/border/padding values. No space left for content"
+            )
+
     def as_dict(self) -> dict:
         return {
             "principal_rect": self.principal_rect.as_dict(),

tests/unit/core/test_geometry.py

@@ -73,3 +73,23 @@ def test_padding_rect_includes_content_padding(self, layered_box: Box):
 
     def test_content_rect_includes_content_only(self, layered_box: Box):
         assert layered_box.content_rect == Rect(189, 126, 264, 206)
+
+    @pytest.mark.parametrize(
+        ("margin", "border", "padding"),
+        [
+            (80, 0, 0),
+            (0, 80, 0),
+            (0, 0, 80),
+            (80, 80, 80),
+        ],
+    )
+    def test_raises_error_on_invalid_perimeters(self, margin, border, padding):
+        box = Box(
+            Rect(100, 100, 100, 100),
+            margin=margin,
+            border=border,
+            padding=padding,
+        )
+        err_msg = "Invalid margin/border/padding values. No space left for content"
+        with pytest.raises(ValueError, match=err_msg):
+            box.validate()