feat(prophet): enable confidence intervals and y_hat without forecast

superset/charts/schemas.py

@@ -542,7 +542,7 @@ class ChartDataProphetOptionsSchema(ChartDataPostProcessingOperationOptionsSchem
     )
     periods = fields.Integer(
         descrption="Time periods (in units of `time_grain`) to predict into the future",
-        min=1,
+        min=0,
         example=7,
         required=True,
     )

superset/utils/pandas_postprocessing.py

@@ -820,8 +820,8 @@ def prophet(  # pylint: disable=too-many-arguments
     freq = PROPHET_TIME_GRAIN_MAP[time_grain]
     # check type at runtime due to marhsmallow schema not being able to handle
     # union types
-    if not periods or periods < 0 or not isinstance(periods, int):
-        raise QueryObjectValidationError(_("Periods must be a positive integer value"))
+    if not isinstance(periods, int) or periods < 0:
+        raise QueryObjectValidationError(_("Periods must be a whole number"))
     if not confidence_interval or confidence_interval <= 0 or confidence_interval >= 1:
         raise QueryObjectValidationError(
             _("Confidence interval must be between 0 and 1 (exclusive)")

tests/integration_tests/pandas_postprocessing_tests.py

@@ -830,6 +830,28 @@ def test_prophet_valid(self):
         assert df[DTTM_ALIAS].iloc[-1].to_pydatetime() == datetime(2022, 5, 31)
         assert len(df) == 9
 
+    def test_prophet_valid_zero_periods(self):
+        pytest.importorskip("prophet")
+
+        df = proc.prophet(
+            df=prophet_df, time_grain="P1M", periods=0, confidence_interval=0.9
+        )
+        columns = {column for column in df.columns}
+        assert columns == {
+            DTTM_ALIAS,
+            "a__yhat",
+            "a__yhat_upper",
+            "a__yhat_lower",
+            "a",
+            "b__yhat",
+            "b__yhat_upper",
+            "b__yhat_lower",
+            "b",
+        }
+        assert df[DTTM_ALIAS].iloc[0].to_pydatetime() == datetime(2018, 12, 31)
+        assert df[DTTM_ALIAS].iloc[-1].to_pydatetime() == datetime(2021, 12, 31)
+        assert len(df) == 4
+
     def test_prophet_import(self):
         prophet = find_spec("prophet")
         if prophet is None:
@@ -875,7 +897,7 @@ def test_prophet_incorrect_periods(self):
             proc.prophet,
             df=prophet_df,
             time_grain="P1M",
-            periods=0,
+            periods=-1,
             confidence_interval=0.8,
         )