Fix tick visibility leaking from styles in alternative axes

ultraplot/config.py

@@ -1296,6 +1296,13 @@ def _get_tickline_props(self, axis=None, which="major", native=True, rebuild=Fal
         context = not rebuild and (native or self._context_mode == 2)
         kwticks = self.category(f"{axis}tick.{which}", context=context)
         kwticks.pop("visible", None)
+
+        # NOTE: We pop visibility properties from the styling dictionary so that
+        # stylistic updates (like applying a dark_background theme) do not override
+        # the tick visibility logic strictly managed by ax._update_locs() and alternate axes.
+        for key in ("bottom", "top", "left", "right"):
+            kwticks.pop(key, None)
+
         for key in ("color", "direction"):
             value = self.find(f"{axis}tick.{key}", context=context)
             if value is not None:

ultraplot/tests/test_axes_alt_styles.py

@@ -0,0 +1,45 @@
+import pytest
+import ultraplot as uplt
+
+
+def test_alt_axes_styling_dark_background():
+    """
+    Test that applying dark_background style does not leak tick visibility
+    settings and correctly preserves alternative axes tick locations.
+    """
+    with uplt.rc.context(style="dark_background"):
+        fig, ax = uplt.subplots()
+        ax.format(ycolor="C0", ylabel="Left Axis")
+
+        ax2 = ax.alty(color="C1")
+        ax2.format(ycolor="C1", ylabel="Right Axis", ylim=(0, 1))
+
+        # The left axis should ONLY have visible ticks on the left
+        left_ax_left_ticks = sum(
+            1
+            for t in ax.yaxis.get_ticklines()
+            if t.get_visible() and t.get_xdata()[0] == 0
+        )
+        left_ax_right_ticks = sum(
+            1
+            for t in ax.yaxis.get_ticklines()
+            if t.get_visible() and t.get_xdata()[0] == 1
+        )
+
+        # The right axis (ax2) should ONLY have visible ticks on the right
+        right_ax_left_ticks = sum(
+            1
+            for t in ax2.yaxis.get_ticklines()
+            if t.get_visible() and t.get_xdata()[0] == 0
+        )
+        right_ax_right_ticks = sum(
+            1
+            for t in ax2.yaxis.get_ticklines()
+            if t.get_visible() and t.get_xdata()[0] == 1
+        )
+
+        assert left_ax_left_ticks > 0, "Left axis should have left ticks"
+        assert left_ax_right_ticks == 0, "Left axis should NOT have right ticks"
+
+        assert right_ax_left_ticks == 0, "Right axis should NOT have left ticks"
+        assert right_ax_right_ticks > 0, "Right axis should have right ticks"