Store figsize in _figure_spec object

Fixes #2891

Author: mwaskom

seaborn/_core/plot.py

@@ -149,10 +149,12 @@ class Plot:
     _limits: dict[str, tuple[Any, Any]]
     _labels: dict[str, str | Callable[[str], str] | None]
 
-    _subplot_spec: dict[str, Any]  # TODO values type
     _facet_spec: FacetSpec
     _pair_spec: PairSpec
 
+    _figure_spec: dict[str, Any]
+    _subplot_spec: dict[str, Any]
+
     def __init__(
         self,
         *args: DataSource | VariableSpec,
@@ -175,10 +177,12 @@ def __init__(
         self._limits = {}
         self._labels = {}
 
-        self._subplot_spec = {}
         self._facet_spec = {}
         self._pair_spec = {}
 
+        self._subplot_spec = {}
+        self._figure_spec = {}
+
         self._target = None
 
     def _resolve_positionals(
@@ -242,10 +246,12 @@ def _clone(self) -> Plot:
         new._labels.update(self._labels)
         new._limits.update(self._limits)
 
-        new._subplot_spec.update(self._subplot_spec)
         new._facet_spec.update(self._facet_spec)
         new._pair_spec.update(self._pair_spec)
 
+        new._figure_spec.update(self._figure_spec)
+        new._subplot_spec.update(self._subplot_spec)
+
         new._target = self._target
 
         return new
@@ -612,8 +618,7 @@ def configure(
 
         new = self._clone()
 
-        # TODO this is a hack; make a proper figure spec object
-        new._figsize = figsize  # type: ignore
+        new._figure_spec["figsize"] = figsize
 
         if sharex is not None:
             new._subplot_spec["sharex"] = sharex
@@ -825,9 +830,8 @@ def _setup_figure(self, p: Plot, common: PlotData, layers: list[Layer]) -> None:
         self._subplots = subplots = Subplots(subplot_spec, facet_spec, pair_spec)
 
         # --- Figure initialization
-        figure_kws = {"figsize": getattr(p, "_figsize", None)}  # TODO fix
         self._figure = subplots.init_figure(
-            pair_spec, self.pyplot, figure_kws, p._target,
+            pair_spec, self.pyplot, p._figure_spec, p._target,
         )
 
         # --- Figure annotation

tests/_core/test_plot.py

@@ -1122,6 +1122,12 @@ def test_2d_with_order(self, long_df, reorder):
         p = Plot(long_df).facet(**variables, order=order)
         self.check_facet_results_2d(p, long_df, variables, order)
 
+    def test_figsize(self):
+
+        figsize = (4, 2)
+        p = Plot().configure(figsize=figsize).plot()
+        assert tuple(p._figure.get_size_inches()) == figsize
+
     def test_axis_sharing(self, long_df):
 
         variables = {"row": "a", "col": "c"}