keep date column in test_scale_lift_measurements (pymc-labs#1316)

pymc_marketing/mmm/lift_test.py

@@ -643,9 +643,19 @@ def scale_lift_measurements(
         target_transform,
     )
 
+    if "date" in df_lift_test.columns:
+        return pd.concat(
+            [
+                df_lift_test_channel_scaled,
+                df_target_scaled,
+                df_sigma_scaled,
+                pd.Series(df_lift_test["date"]),
+            ],
+            axis=1,
+        )
+
     return pd.concat(
-        [df_lift_test_channel_scaled, df_target_scaled, df_sigma_scaled],
-        axis=1,
+        [df_lift_test_channel_scaled, df_target_scaled, df_sigma_scaled], axis=1
     )
 
 

tests/mmm/test_lift_test.py

@@ -474,9 +474,14 @@ def test_scale_lift_measurements(df_lift_test_with_numerics) -> None:
         delta_x=lambda row: row["delta_x"] * 2.0,
         delta_y=lambda row: row["delta_y"] / 2,
         sigma=lambda row: row["sigma"] / 2,
-    ).loc[:, ["channel", "x", "delta_x", "delta_y", "sigma"]]
+    ).loc[
+        :,
+        ["channel", "x", "delta_x", "delta_y", "sigma"]
+        + (["date"] if "date" in df_lift_test_with_numerics.columns else []),
+    ]
 
     pd.testing.assert_frame_equal(
         result,
         expected,
+        check_like=True,
     )

tests/mmm/test_mmm.py

@@ -1101,6 +1101,20 @@ def df_lift_test() -> pd.DataFrame:
     )
 
 
+@pytest.fixture
+def df_lift_test_with_date() -> pd.DataFrame:
+    return pd.DataFrame(
+        {
+            "channel": ["channel_1", "channel_1"],
+            "x": [1, 2],
+            "delta_x": [1, 1],
+            "delta_y": [1, 1],
+            "sigma": [1, 1],
+            "date": pd.to_datetime(["2020-08-10", "2020-08-31"]),
+        }
+    )
+
+
 def test_add_lift_test_measurements(mmm, toy_X, toy_y, df_lift_test) -> None:
     mmm.build_model(X=toy_X, y=toy_y)
 
@@ -1314,3 +1328,23 @@ def test_channel_contributions_forward_pass_time_varying_media(toy_X, toy_y) ->
         recovered_contributions.to_numpy(),
         media_contributions,
     )
+
+
+def test_time_varying_media_with_lift_test(
+    toy_X, toy_y, df_lift_test_with_date
+) -> None:
+    mmm = MMM(
+        date_column="date",
+        channel_columns=["channel_1", "channel_2"],
+        control_columns=["control_1", "control_2"],
+        adstock=GeometricAdstock(l_max=2),
+        saturation=LogisticSaturation(),
+        time_varying_media=True,
+    )
+    mmm.build_model(X=toy_X, y=toy_y)
+    try:
+        mmm.add_lift_test_measurements(df_lift_test_with_date)
+    except Exception as e:
+        pytest.fail(
+            f"add_lift_test_measurements for time_varying_media model failed with error {e}"
+        )