Warn with default format for type when not found (#273)

* Warn with default format for type when not found

* - fix code style
- add unittest

Co-authored-by: Koudai Aono <koxudaxi@gmail.com>

datamodel_code_generator/parser/jsonschema.py

@@ -14,6 +14,7 @@
     Type,
     Union,
 )
+from warnings import warn
 
 import yaml
 from pydantic import BaseModel, Field, root_validator, validator
@@ -253,9 +254,17 @@ def get_data_type(self, obj: JsonSchemaObject) -> DataType:
             return self.data_type_manager.get_data_type(Types.any)
 
         def _get_data_type(type_: str, format__: str) -> DataType:
+            data_formats: Optional[Types] = json_schema_data_formats[type_].get(
+                format__
+            )
+            if data_formats is None:
+                warn(
+                    "format of {!r} not understood for {!r} - using default"
+                    "".format(format__, type_)
+                )
+                data_formats = json_schema_data_formats[type_]['default']
             return self.data_type_manager.get_data_type(
-                json_schema_data_formats[type_][format__],
-                **obj.dict() if not self.field_constraints else {},
+                data_formats, **obj.dict() if not self.field_constraints else {},
             )
 
         if isinstance(obj.type, list):

tests/parser/test_jsonschema.py

@@ -348,6 +348,7 @@ def test_parse_nested_array():
         ('string', 'uuid5', 'UUID5', 'pydantic', 'UUID5'),
         ('string', 'ipv4', 'IPv4Address', 'pydantic', 'IPv4Address'),
         ('string', 'ipv6', 'IPv6Address', 'pydantic', 'IPv6Address'),
+        ('string', 'unknown-type', 'str', None, None),
     ],
 )
 def test_get_data_type(schema_type, schema_format, result_type, from_, import_):