Added test_hist in test_datetime.py (matplotlib#27028)

* Added test_hist

* reset

* remove comment

* Added test_hist

* added test_hist.py to test_datetime.py

* comply with PEP8

* datetime as bins

* datetime as bins

Author: yangyangdotcom

lib/matplotlib/tests/test_datetime.py

@@ -170,11 +170,52 @@ def test_hexbin(self):
         fig, ax = plt.subplots()
         ax.hexbin(...)
 
-    @pytest.mark.xfail(reason="Test for hist not written yet")
     @mpl.style.context("default")
     def test_hist(self):
-        fig, ax = plt.subplots()
-        ax.hist(...)
+        mpl.rcParams["date.converter"] = 'concise'
+
+        start_date = datetime.datetime(2023, 10, 1)
+        time_delta = datetime.timedelta(days=1)
+
+        values1 = np.random.randint(1, 10, 30)
+        values2 = np.random.randint(1, 10, 30)
+        values3 = np.random.randint(1, 10, 30)
+
+        bin_edges = [start_date + i * time_delta for i in range(31)]
+
+        fig, (ax1, ax2, ax3) = plt.subplots(3, 1, constrained_layout=True)
+        ax1.hist(
+            [start_date + i * time_delta for i in range(30)],
+            bins=10,
+            weights=values1
+        )
+        ax2.hist(
+            [start_date + i * time_delta for i in range(30)],
+            bins=10,
+            weights=values2
+        )
+        ax3.hist(
+            [start_date + i * time_delta for i in range(30)],
+            bins=10,
+            weights=values3
+        )
+
+        fig, (ax4, ax5, ax6) = plt.subplots(3, 1, constrained_layout=True)
+        ax4.hist(
+            [start_date + i * time_delta for i in range(30)],
+            bins=bin_edges,
+            weights=values1
+        )
+        ax5.hist(
+            [start_date + i * time_delta for i in range(30)],
+            bins=bin_edges,
+            weights=values2
+        )
+        ax6.hist(
+            [start_date + i * time_delta for i in range(30)],
+            bins=bin_edges,
+            weights=values3
+        )
 
     @pytest.mark.xfail(reason="Test for hist2d not written yet")
     @mpl.style.context("default")