From 572030befecc70fe6da19ca5c35f7b5d5867d327 Mon Sep 17 00:00:00 2001
From: Michael Waskom <mwaskom@gmail.com>
Date: Thu, 22 Dec 2022 21:22:03 -0500
Subject: [PATCH] Fix Plot.on tests to work with new logic

---
 doc/whatsnew/v0.12.2.rst |  2 ++
 seaborn/_core/plot.py    | 10 +++-------
 tests/_core/test_plot.py |  6 +++---
 3 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/doc/whatsnew/v0.12.2.rst b/doc/whatsnew/v0.12.2.rst
index ad12a778e1..aa8def9a0b 100644
--- a/doc/whatsnew/v0.12.2.rst
+++ b/doc/whatsnew/v0.12.2.rst
@@ -8,6 +8,8 @@ v0.12.2 (Unreleased)
 
 - |Fix| Fixed a bug where legends for numeric variables with large values with be incorrectly shown (i.e. with a missing offset or exponent; :pr:`3187`).
 
+- |Fix| Improve robustness to empty data in several components of the objects interface (:pr:`3202`).
+
 - |Fix| Fixed a regression in v0.12.0 where manually-added labels could have duplicate legend entries (:pr:`3116`).
 
 - |Fix| Fixed a bug in :func:`histplot` with `kde=True` and `log_scale=True` where the curve was not scaled properly (:pr:`3173`).
diff --git a/seaborn/_core/plot.py b/seaborn/_core/plot.py
index 687a992a01..64f59cb239 100644
--- a/seaborn/_core/plot.py
+++ b/seaborn/_core/plot.py
@@ -1466,8 +1466,6 @@ def _setup_split_generator(
         self, grouping_vars: list[str], df: DataFrame, subplots: list[dict[str, Any]],
     ) -> Callable[[], Generator]:
 
-        allow_empty = False  # TODO will need to recreate previous categorical plots
-
         grouping_keys = []
         grouping_vars = [
             v for v in grouping_vars if v in df and v not in ["col", "row"]
@@ -1506,11 +1504,9 @@ def split_generator(keep_na=False) -> Generator:
                         subplot_keys[dim] = view[dim]
 
                 if not grouping_vars or not any(grouping_keys):
-                    if axes_df.empty and not allow_empty:
-                        continue
-                    else:
+                    if not axes_df.empty:
                         yield subplot_keys, axes_df.copy(), view["ax"]
-                        continue
+                    continue
 
                 grouped_df = axes_df.groupby(grouping_vars, sort=False, as_index=False)
 
@@ -1529,7 +1525,7 @@ def split_generator(keep_na=False) -> Generator:
                         # case this option could be removed
                         df_subset = axes_df.loc[[]]
 
-                    if df_subset.empty and not allow_empty:
+                    if df_subset.empty:
                         continue
 
                     sub_vars = dict(zip(grouping_vars, key))
diff --git a/tests/_core/test_plot.py b/tests/_core/test_plot.py
index 8d3a22922c..506739624e 100644
--- a/tests/_core/test_plot.py
+++ b/tests/_core/test_plot.py
@@ -1087,7 +1087,7 @@ def test_on_axes(self):
 
         ax = mpl.figure.Figure().subplots()
         m = MockMark()
-        p = Plot().on(ax).add(m).plot()
+        p = Plot([1], [2]).on(ax).add(m).plot()
         assert m.passed_axes == [ax]
         assert p._figure is ax.figure
 
@@ -1096,7 +1096,7 @@ def test_on_figure(self, facet):
 
         f = mpl.figure.Figure()
         m = MockMark()
-        p = Plot().on(f).add(m)
+        p = Plot([1, 2], [3, 4]).on(f).add(m)
         if facet:
             p = p.facet(["a", "b"])
         p = p.plot()
@@ -1113,7 +1113,7 @@ def test_on_subfigure(self, facet):
         sf1, sf2 = mpl.figure.Figure().subfigures(2)
         sf1.subplots()
         m = MockMark()
-        p = Plot().on(sf2).add(m)
+        p = Plot([1, 2], [3, 4]).on(sf2).add(m)
         if facet:
             p = p.facet(["a", "b"])
         p = p.plot()