add UUID field (#106)

Author: aminalaee

tests/test_fields.py

@@ -5,6 +5,7 @@
 
 from typesystem.base import Message, ValidationError
 from typesystem.fields import (
+    UUID,
     Array,
     Boolean,
     Choice,
@@ -715,13 +716,13 @@ def test_datetime():
 
 
 def test_uuid():
-    validator = String(format="uuid")
+    validator = UUID()
     value, error = validator.validate_or_error("93e19019-c7a6-45fe-8936-f6f4d550f35f")
     assert value == uuid.UUID("93e19019-c7a6-45fe-8936-f6f4d550f35f")
 
-    validator = String(format="uuid")
+    validator = UUID()
     value, error = validator.validate_or_error("1245a678-1234-1234-1234-123412341234")
-    assert error == ValidationError(text="Must be valid UUID format.", code="format")
+    assert error == ValidationError(text="Must be a valid UUID format.", code="format")
 
 
 def test_union():

typesystem/__init__.py

@@ -1,5 +1,6 @@
 from typesystem.base import Message, ParseError, Position, ValidationError
 from typesystem.fields import (
+    UUID,
     Any,
     Array,
     Boolean,
@@ -44,6 +45,7 @@
     "Text",
     "Time",
     "Union",
+    "UUID",
     # Schemas
     "Schema",
     "SchemaDefinitions",

typesystem/fields.py

@@ -760,3 +760,8 @@ def validate(self, value: typing.Any, strict: bool = False) -> typing.Any:
                 raise self.validation_error("only_null")
             raise self.validation_error("const")
         return value
+
+
+class UUID(String):
+    def __init__(self, **kwargs: typing.Any) -> None:
+        super().__init__(format="uuid", **kwargs)

typesystem/formats.py

@@ -155,7 +155,7 @@ def serialize(self, obj: typing.Any) -> typing.Union[str, None]:
 
 
 class UUIDFormat(BaseFormat):
-    errors = {"format": "Must be valid UUID format."}
+    errors = {"format": "Must be a valid UUID format."}
 
     def is_native_type(self, value: typing.Any) -> bool:
         return isinstance(value, uuid.UUID)