feat: Adds Histogram chart migration logic (#28780)

tests/unit_tests/migrations/viz/histogram_v1_v2_test.py

@@ -0,0 +1,52 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from typing import Any
+
+from superset.migrations.shared.migrate_viz import MigrateHistogramChart
+from tests.unit_tests.migrations.viz.utils import migrate_and_assert
+
+SOURCE_FORM_DATA: dict[str, Any] = {
+    "all_columns_x": ["category"],
+    "adhoc_filters": [],
+    "cumulative": True,
+    "linear_color_scheme": "blue",
+    "link_length": "5",
+    "normalized": True,
+    "row_limit": 100,
+    "viz_type": "histogram",
+    "x_axis_label": "X",
+    "y_axis_label": "Y",
+}
+
+TARGET_FORM_DATA: dict[str, Any] = {
+    "adhoc_filters": [],
+    "bins": 5,
+    "column": "category",
+    "cumulative": True,
+    "form_data_bak": SOURCE_FORM_DATA,
+    "groupby": [],
+    "linear_color_scheme": "blue",
+    "normalize": True,
+    "row_limit": 100,
+    "viz_type": "histogram_v2",
+    "x_axis_title": "X",
+    "y_axis_title": "Y",
+}
+
+
+def test_migration() -> None:
+    migrate_and_assert(MigrateHistogramChart, SOURCE_FORM_DATA, TARGET_FORM_DATA)

tests/unit_tests/pandas_postprocessing/test_histogram.py

@@ -120,3 +120,25 @@ def test_histogram_with_non_numeric_column():
         histogram(data, "b", ["group"], bins)
     except ValueError as e:
         assert str(e) == "The column 'b' must be numeric."
+
+
+# test histogram ignore null values
+def test_histogram_ignore_null_values():
+    data_with_null = DataFrame(
+        {
+            "group": ["A", "A", "B", "B", "A", "A", "B", "B", "A", "A"],
+            "a": [1, 2, 3, 4, 5, 6, 7, 8, 9, None],
+            "b": [1, 2, 3, 4, 5, 6, 7, 8, 9, None],
+        }
+    )
+    result = histogram(data_with_null, "a", ["group"], bins)
+    assert result.shape == (2, bins + 1)
+    assert result.columns.tolist() == [
+        "group",
+        "1 - 2",
+        "2 - 4",
+        "4 - 5",
+        "5 - 7",
+        "7 - 9",
+    ]
+    assert result.values.tolist() == [["A", 2, 0, 1, 1, 1], ["B", 0, 2, 0, 1, 1]]