Honor patch linewidth rc for edgefix (#649)

Preserve rc['patch.linewidth'] for patch-style 2D artists when edgefix is active, and add targeted regressions for bar, hist, pie, and fill_between while leaving collection edgefix behavior unchanged.\n\nCloses #648

Author: cvanelteren

ultraplot/axes/plot.py

@@ -3509,7 +3509,9 @@ def _fix_sticky_edges(self, objs, axis, *args, only=None):
                 edges.extend(convert((min_, max_)))
 
     @staticmethod
-    def _fix_patch_edges(obj, edgefix=None, **kwargs):
+    def _fix_patch_edges(
+        obj, edgefix=None, default_linewidth: float | None = None, **kwargs
+    ):
         """
         Fix white lines between between filled patches and fix issues
         with colormaps that are transparent. If keyword args passed by user
@@ -3520,7 +3522,11 @@ def _fix_patch_edges(obj, edgefix=None, **kwargs):
         # See: https://github.com/jklymak/contourfIssues
         # See: https://stackoverflow.com/q/15003353/4970632
         edgefix = _not_none(edgefix, rc.edgefix, True)
-        linewidth = EDGEWIDTH if edgefix is True else 0 if edgefix is False else edgefix
+        linewidth = (
+            _not_none(default_linewidth, EDGEWIDTH)
+            if edgefix is True
+            else 0 if edgefix is False else edgefix
+        )
         if not linewidth:
             return
         keys = ("linewidth", "linestyle", "edgecolor")  # patches and collections
@@ -3557,7 +3563,9 @@ def _fix_patch_edges(obj, edgefix=None, **kwargs):
             obj.set_edgecolor(obj.get_facecolor())
         elif np.iterable(obj):  # e.g. silent_list of BarContainer
             for element in obj:
-                PlotAxes._fix_patch_edges(element, edgefix=edgefix)
+                PlotAxes._fix_patch_edges(
+                    element, edgefix=edgefix, default_linewidth=default_linewidth
+                )
         else:
             warnings._warn_ultraplot(
                 f"Unexpected obj {obj} passed to _fix_patch_edges."
@@ -5756,7 +5764,9 @@ def _apply_fill(
             # No synthetic tagging or seaborn-based label overrides
 
             # Patch edge fixes
-            self._fix_patch_edges(obj, **edgefix_kw, **kw)
+            self._fix_patch_edges(
+                obj, default_linewidth=rc["patch.linewidth"], **edgefix_kw, **kw
+            )
 
             # Track sides for sticky edges
             xsides.append(x)
@@ -6039,7 +6049,9 @@ def _apply_bar(
                 if isinstance(obj, mcontainer.BarContainer):
                     self._add_bar_labels(obj, orientation=orientation, **bar_labels_kw)
 
-            self._fix_patch_edges(obj, **edgefix_kw, **kw)
+            self._fix_patch_edges(
+                obj, default_linewidth=rc["patch.linewidth"], **edgefix_kw, **kw
+            )
             for y in (b, b + h):
                 self._inbounds_xylim(extents, x, y, orientation=orientation)
 
@@ -6162,7 +6174,9 @@ def pie(self, x, explode, *, labelpad=None, labeldistance=None, **kwargs):
             **kw,
         )
         objs = tuple(cbook.silent_list(type(seq[0]).__name__, seq) for seq in objs)
-        self._fix_patch_edges(objs[0], **edgefix_kw, **wedge_kw)
+        self._fix_patch_edges(
+            objs[0], default_linewidth=rc["patch.linewidth"], **edgefix_kw, **wedge_kw
+        )
         return objs
 
     @staticmethod
@@ -7074,7 +7088,9 @@ def _apply_hist(
         kw = self._parse_cycle(n, **kw)
         obj = self._call_native("hist", xs, orientation=orientation, **kw)
         if histtype.startswith("bar"):
-            self._fix_patch_edges(obj[2], **edgefix_kw, **kw)
+            self._fix_patch_edges(
+                obj[2], default_linewidth=rc["patch.linewidth"], **edgefix_kw, **kw
+            )
         # Revert to mpl < 3.3 behavior where silent_list was always returned for
         # non-bar-type histograms. Because consistency.
         res = obj[2]

ultraplot/tests/test_plot.py

@@ -99,6 +99,45 @@ def test_error_shading_explicit_label_external():
     assert "Band" in labels
 
 
+def test_patch_linewidth_rc_controls_patch_edgefix() -> None:
+    """
+    Patch-style artists should honor rc patch linewidth even when edge-fix is active.
+    """
+    expected = 3.5
+    with uplt.rc.context({"patch.linewidth": expected}):
+        fig, axs = uplt.subplots(ncols=4)
+
+        bar = axs[0].bar([1, 2], [3, 4])
+        fill = axs[1].fill_between([0, 1, 2], [1, 2, 1])
+        hist = axs[2].hist(np.arange(5))
+        pie = axs[3].pie([1, 2, 3])
+
+        assert [patch.get_linewidth() for patch in bar.patches] == pytest.approx(
+            [expected, expected]
+        )
+        assert np.atleast_1d(fill.get_linewidths()) == pytest.approx([expected])
+        assert [patch.get_linewidth() for patch in hist[2]] == pytest.approx(
+            [expected] * len(hist[2])
+        )
+        assert [wedge.get_linewidth() for wedge in pie[0]] == pytest.approx(
+            [expected] * len(pie[0])
+        )
+
+    uplt.close(fig)
+
+
+def test_patch_linewidth_rc_does_not_override_collection_edgefix() -> None:
+    """
+    Collection-style 2D artists keep their dedicated edge-fix linewidth.
+    """
+    with uplt.rc.context({"patch.linewidth": 3.5}):
+        fig, ax = uplt.subplots()
+        mesh = ax.pcolormesh(np.arange(9).reshape(3, 3))
+        assert np.atleast_1d(mesh.get_linewidth()) == pytest.approx([0.3])
+
+    uplt.close(fig)
+
+
 def test_graph_nodes_kw():
     """Test the graph method by setting keywords for nodes"""
     import networkx as nx