From c0ebd7f434b2c6902dd79a8c2ba46ca71fafd329 Mon Sep 17 00:00:00 2001
From: Ville Brofeldt <33317356+villebro@users.noreply.github.com>
Date: Thu, 13 Aug 2020 20:51:03 +0300
Subject: [PATCH] fix: show error if rolling window returns empty df (#10572)

* fix: show error if rolling window returns empty df

* add test
---
 superset/viz.py    |  8 ++++++++
 tests/viz_tests.py | 23 ++++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/superset/viz.py b/superset/viz.py
index 88d67bb03..34054cb40 100644
--- a/superset/viz.py
+++ b/superset/viz.py
@@ -216,6 +216,14 @@ class BaseViz:
             df = df.cumsum()
         if min_periods:
             df = df[min_periods:]
+        if df.empty:
+            raise QueryObjectValidationError(
+                _(
+                    "Applied rolling window did not return any data. Please make sure "
+                    "the source query satisfies the minimum periods defined in the "
+                    "rolling window."
+                )
+            )
         return df
 
     def get_samples(self) -> List[Dict[str, Any]]:
diff --git a/tests/viz_tests.py b/tests/viz_tests.py
index 3689901dc..637cd33cc 100644
--- a/tests/viz_tests.py
+++ b/tests/viz_tests.py
@@ -24,12 +24,13 @@ from typing import Any, Dict, List, Set
 
 import numpy as np
 import pandas as pd
+import pytest
 
 import tests.test_app
 import superset.viz as viz
 from superset import app
 from superset.constants import NULL_STRING
-from superset.exceptions import SpatialException
+from superset.exceptions import QueryObjectValidationError, SpatialException
 from superset.utils.core import DTTM_ALIAS
 
 from .base_tests import SupersetTestCase
@@ -1266,6 +1267,26 @@ class TestTimeSeriesViz(SupersetTestCase):
             [1.0, 1.5, 2.0, 2.5],
         )
 
+    def test_apply_rolling_without_data(self):
+        datasource = self.get_datasource_mock()
+        df = pd.DataFrame(
+            index=pd.to_datetime(
+                ["2019-01-01", "2019-01-02", "2019-01-05", "2019-01-07"]
+            ),
+            data={"y": [1.0, 2.0, 3.0, 4.0]},
+        )
+        test_viz = viz.BigNumberViz(
+            datasource,
+            {
+                "metrics": ["y"],
+                "rolling_type": "cumsum",
+                "rolling_periods": 4,
+                "min_periods": 4,
+            },
+        )
+        with pytest.raises(QueryObjectValidationError):
+            test_viz.apply_rolling(df)
+
 
 class TestBigNumberViz(SupersetTestCase):
     def test_get_data(self):