Support lists as field value choices

src/protean/fields/base.py

@@ -91,13 +91,6 @@ def __init__(
 
         # Set the choices for this field
         self.choices = choices
-        if self.choices:
-            self.choice_dict = {}
-            for _, member in self.choices.__members__.items():
-                if isinstance(member.value, (tuple, list)):
-                    self.choice_dict[member.value[0]] = member.value[1]
-                else:
-                    self.choice_dict[member.value] = member.value
 
         self._validators = validators
 
@@ -251,12 +244,23 @@ def _load(self, value: Any):
 
         # If choices exist then validate that value is be one of the choices
         if self.choices:
-            value_list = value
-            if not isinstance(value, (list, tuple)):
-                value_list = [value]
+            # Check if self.choices is an Enum
+            if type(self.choices) not in [list, tuple] and issubclass(
+                self.choices, enum.Enum
+            ):
+                choices = [item.value for item in self.choices]
+
+                # Check if value is an Enum instance
+                if isinstance(value, self.choices):
+                    value = value.value
+            else:
+                choices = self.choices
+
+            value_list = [value] if not isinstance(value, (list, tuple)) else value
+
             for v in value_list:
-                if v not in self.choice_dict:
-                    self.fail("invalid_choice", value=v, choices=list(self.choice_dict))
+                if v not in choices:
+                    self.fail("invalid_choice", value=v, choices=choices)
 
         # Cast and Validate the value for this Field
         value = self._cast_to_type(value)

src/protean/fields/basic.py

@@ -40,9 +40,6 @@ def __init__(self, max_length=255, min_length=None, sanitize=True, **kwargs):
 
     def _cast_to_type(self, value):
         """Convert the value to its string representation"""
-        if value is None:
-            return value
-
         value = value if isinstance(value, str) else str(value)
 
         return bleach.clean(value) if self.sanitize else value
@@ -77,9 +74,6 @@ def __init__(self, sanitize=True, **kwargs):
 
     def _cast_to_type(self, value):
         """Convert the value to its string representation"""
-        if value is None:
-            return value
-
         value = value if isinstance(value, str) else str(value)
 
         return bleach.clean(value) if self.sanitize else value

tests/field/test_choices.py

@@ -0,0 +1,57 @@
+import pytest
+
+from enum import Enum
+
+from protean.exceptions import ValidationError
+from protean.fields import String
+
+
+def test_choices_as_enum():
+    """Test choices validations for the string field"""
+
+    class StatusChoices(Enum):
+        """Set of choices for the status"""
+
+        PENDING = "Pending"
+        SUCCESS = "Success"
+        ERROR = "Error"
+
+    status = String(max_length=10, choices=StatusChoices)
+    assert status is not None
+
+    # Test loading a value
+    assert status._load("Pending") == "Pending"
+    # Test loading an Enum
+    assert status._load(StatusChoices.PENDING) == "Pending"
+
+    # Test invalid value
+    with pytest.raises(ValidationError) as e_info:
+        status._load("Failure")
+
+    assert e_info.value.messages == {
+        "unlinked": [
+            "Value `'Failure'` is not a valid choice. "
+            "Must be among ['Pending', 'Success', 'Error']"
+        ]
+    }
+
+
+def test_choices_as_list():
+    """Test choices validations for the string field"""
+
+    status = String(max_length=10, choices=["Pending", "Success", "Error"])
+    assert status is not None
+
+    # Test loading a value
+    assert status._load("Pending") == "Pending"
+
+    # Test invalid value
+    with pytest.raises(ValidationError) as e_info:
+        status._load("Failure")
+
+    assert e_info.value.messages == {
+        "unlinked": [
+            "Value `'Failure'` is not a valid choice. "
+            "Must be among ['Pending', 'Success', 'Error']"
+        ]
+    }

tests/field/test_field_types.py

@@ -31,6 +31,10 @@ def test_init(self):
         name = String(max_length=10)
         assert name is not None
 
+    def test_returns_none_as_it_is(self):
+        name = String(max_length=10)
+        assert name._load(None) is None
+
     def test_type_validation(self):
         """Test type checking validation for the Field"""
         name = String(max_length=10)
@@ -117,9 +121,9 @@ def test_choice(self):
         class StatusChoices(enum.Enum):
             """Set of choices for the status"""
 
-            PENDING = (0, "Pending")
-            SUCCESS = (1, "Success")
-            ERROR = (2, "Error")
+            PENDING = 0
+            SUCCESS = 1
+            ERROR = 2
 
         status = Integer(choices=StatusChoices)
         assert status is not None