Merge pull request #331 from proteanhq/196-restrict-list-to-specific-…

…content-type

Restrict `List` datatype to specific content types

src/protean/core/field/basic.py

@@ -140,12 +140,43 @@ class List(Field):
 
     default_error_messages = {
         "invalid": '"{value}" value must be of list type.',
+        "invalid_content": "Invalid value",
     }
 
+    def __init__(self, content_type=String, **kwargs):
+        if content_type not in [
+            String,
+            Integer,
+            Identifier,
+            Float,
+            Date,
+            DateTime,
+            Boolean,
+        ]:
+            raise ValidationError({"content_type": ["Content type not supported"]})
+        self.content_type = content_type
+
+        super().__init__(**kwargs)
+
     def _cast_to_type(self, value):
-        """ Raise error if the value is not a list """
+        """ Raise errors if the value is not a list, or
+        the items in the list are not of the right data type.
+        """
         if not isinstance(value, list):
             self.fail("invalid", value=value)
+
+        # Try to cast value into the destination type.
+        #   Throw error if the underlying type does not support value.
+        new_value = []
+        try:
+            for item in value:
+                new_value.append(self.content_type()._load(item))
+        except ValidationError:
+            self.fail("invalid_content", value=value)
+
+        if new_value != value:
+            self.fail("invalid_content", value=value)
+
         return value
 
 
@@ -176,7 +207,9 @@ def __init__(self, content_type=String, **kwargs):
         super().__init__(**kwargs)
 
     def _cast_to_type(self, value):
-        """ Raise error if the value is not a list """
+        """ Raise errors if the value is not a list, or
+        the items in the list are not of the right data type.
+        """
         if not isinstance(value, list):
             self.fail("invalid", value=value)
 

tests/impl/model/dict_model/test_list_datatype.py

@@ -0,0 +1,89 @@
+import pytest
+
+from datetime import datetime
+
+from protean.core.aggregate import BaseAggregate
+from protean.core.exceptions import ValidationError
+from protean.core.field.basic import (
+    List,
+    Auto,
+    Boolean,
+    Date,
+    DateTime,
+    Float,
+    Identifier,
+    Integer,
+    String,
+)
+
+
+class ListUser(BaseAggregate):
+    email = String(max_length=255, required=True, unique=True)
+    roles = List()  # Defaulted to String Content Type
+
+
+class IntegerListUser(BaseAggregate):
+    email = String(max_length=255, required=True, unique=True)
+    roles = List(content_type=Integer)
+
+
+@pytest.mark.postgresql
+def test_basic_array_data_type_support(test_domain):
+    test_domain.register(ListUser)
+
+    model_cls = test_domain.get_model(ListUser)
+    user = ListUser(email="[email protected]", roles=["ADMIN", "USER"])
+    user_model_obj = model_cls.from_entity(user)
+
+    user_copy = model_cls.to_entity(user_model_obj)
+    assert user_copy is not None
+    assert user_copy.roles == ["ADMIN", "USER"]
+
+
+@pytest.mark.postgresql
+def test_array_content_type_validation(test_domain):
+    test_domain.register(ListUser)
+    test_domain.register(IntegerListUser)
+
+    for kwargs in [
+        {"email": "[email protected]", "roles": [1, 2]},
+        {"email": "[email protected]", "roles": ["1", 2]},
+        {"email": "[email protected]", "roles": [1.0, 2.0]},
+        {"email": "[email protected]", "roles": [datetime.utcnow()]},
+    ]:
+        with pytest.raises(ValidationError) as exception:
+            ListUser(**kwargs)
+        assert exception.value.messages == {"roles": ["Invalid value"]}
+
+    model_cls = test_domain.get_model(IntegerListUser)
+    user = IntegerListUser(email="[email protected]", roles=[1, 2])
+    user_model_obj = model_cls.from_entity(user)
+
+    user_copy = model_cls.to_entity(user_model_obj)
+    assert user_copy is not None
+    assert user_copy.roles == [1, 2]
+
+    for kwargs in [
+        {"email": "[email protected]", "roles": ["ADMIN", "USER"]},
+        {"email": "[email protected]", "roles": ["1", "2"]},
+        {"email": "[email protected]", "roles": [datetime.utcnow()]},
+    ]:
+        with pytest.raises(ValidationError) as exception:
+            IntegerListUser(**kwargs)
+        assert exception.value.messages == {"roles": ["Invalid value"]}
+
+
+@pytest.mark.postgresql
+def test_that_only_specific_primitive_types_are_allowed_as_content_types(test_domain):
+    List(content_type=String)
+    List(content_type=Identifier)
+    List(content_type=Integer)
+    List(content_type=Float)
+    List(content_type=Boolean)
+    List(content_type=Date)
+    List(content_type=DateTime)
+
+    with pytest.raises(ValidationError) as error:
+        List(content_type=Auto)
+
+    assert error.value.messages == {"content_type": ["Content type not supported"]}