Fallback to defaults in adstock|saturation_from_dict (#955)

* Default saturation_from_dict to default_priors

* Default to AdstockTransformation.default priors in adstock_from_dict

pymc_marketing/mmm/components/adstock.py

@@ -405,7 +405,8 @@ def adstock_from_dict(data: dict) -> AdstockTransformation:
     lookup_name = data.pop("lookup_name")
     cls = ADSTOCK_TRANSFORMATIONS[lookup_name]
 
-    data["priors"] = {k: Prior.from_json(v) for k, v in data["priors"].items()}
+    if "priors" in data:
+        data["priors"] = {k: Prior.from_json(v) for k, v in data["priors"].items()}
     return cls(**data)
 
 

pymc_marketing/mmm/components/saturation.py

@@ -465,9 +465,10 @@ def saturation_from_dict(data: dict) -> SaturationTransformation:
     data = data.copy()
     cls = SATURATION_TRANSFORMATIONS[data.pop("lookup_name")]
 
-    data["priors"] = {
-        key: Prior.from_json(value) for key, value in data["priors"].items()
-    }
+    if "priors" in data:
+        data["priors"] = {
+            key: Prior.from_json(value) for key, value in data["priors"].items()
+        }
     return cls(**data)
 
 

tests/mmm/components/test_adstock.py

@@ -178,6 +178,24 @@ def test_adstock_from_dict() -> None:
     )
 
 
+@pytest.mark.parametrize(
+    "adstock",
+    adstocks(),
+)
+def test_adstock_from_dict_without_priors(adstock) -> None:
+    data = {
+        "lookup_name": adstock.lookup_name,
+        "l_max": 10,
+        "prefix": "test",
+        "mode": "Before",
+    }
+
+    adstock = adstock_from_dict(data)
+    assert adstock.default_priors == {
+        k: Prior.from_json(v) for k, v in adstock.to_dict()["priors"].items()
+    }
+
+
 def test_register_adstock_transformation() -> None:
     class NewTransformation(AdstockTransformation):
         lookup_name: str = "new_transformation"

tests/mmm/components/test_saturation.py

@@ -258,3 +258,15 @@ def test_saturation_from_dict() -> None:
             "lam": Prior("HalfNormal", sigma=1),
         }
     )
+
+
+@pytest.mark.parametrize("saturation", saturation_functions())
+def test_saturation_from_dict_without_priors(saturation) -> None:
+    data = {
+        "lookup_name": saturation.lookup_name,
+    }
+
+    saturation = saturation_from_dict(data)
+    assert saturation.default_priors == {
+        k: Prior.from_json(v) for k, v in saturation.to_dict()["priors"].items()
+    }