Add test for fill_between in test_datetime.py (#27423)

linyilily · Linyi Li · web-flow · commit f3585ef56a4d · 2023-12-05T13:00:01.000+01:00
* add test for fill_between in test_datetime.py

* fix error in checks

* make y values always increasing

* second plot removed as requested

* oops forgot to remove savefig

---------

Co-authored-by: Linyi Li &lt;linyi.li@mail.utoronto.ca&gt;
diff --git a/lib/matplotlib/tests/test_datetime.py b/lib/matplotlib/tests/test_datetime.py
@@ -311,11 +311,40 @@ def test_fill(self):
         ax3.fill(x_values, y_values)
         ax4.fill(x_dates, y_dates)
 
-    @pytest.mark.xfail(reason="Test for fill_between not written yet")
     @mpl.style.context("default")
     def test_fill_between(self):
-        fig, ax = plt.subplots()
-        ax.fill_between(...)
+        mpl.rcParams["date.converter"] = "concise"
+        np.random.seed(19680801)
+
+        y_base_date = datetime.datetime(2023, 1, 1)
+        y_dates1 = [y_base_date]
+        for i in range(1, 10):
+            y_base_date += datetime.timedelta(days=np.random.randint(1, 5))
+            y_dates1.append(y_base_date)
+
+        y_dates2 = [y_base_date]
+        for i in range(1, 10):
+            y_base_date += datetime.timedelta(days=np.random.randint(1, 5))
+            y_dates2.append(y_base_date)
+        x_values = np.random.rand(10) * 10
+        x_values.sort()
+
+        y_values1 = np.random.rand(10) * 10
+        y_values2 = y_values1 + np.random.rand(10) * 10
+        y_values1.sort()
+        y_values2.sort()
+
+        x_base_date = datetime.datetime(2023, 1, 1)
+        x_dates = [x_base_date]
+        for i in range(1, 10):
+            x_base_date += datetime.timedelta(days=np.random.randint(1, 10))
+            x_dates.append(x_base_date)
+
+        fig, (ax1, ax2, ax3) = plt.subplots(3, 1, layout="constrained")
+
+        ax1.fill_between(x_values, y_dates1, y_dates2)
+        ax2.fill_between(x_dates, y_values1, y_values2)
+        ax3.fill_between(x_dates, y_dates1, y_dates2)
 
     @pytest.mark.xfail(reason="Test for fill_betweenx not written yet")
     @mpl.style.context("default")
