refactor: Switch _PythonIdentifier to a public custom class in utils

Author: dbanty

Diff for: openapi_python_client/parser/openapi.py

@@ -11,7 +11,6 @@
 from ..config import Config
 from .errors import GeneratorError, ParseError, PropertyError
 from .properties import Class, EnumProperty, ModelProperty, Property, Schemas, build_schemas, property_from_data
-from .properties.property import _PythonIdentifier, to_valid_python_identifier
 from .responses import Response, response_from_data
 
 
@@ -31,9 +30,9 @@ class EndpointCollection:
     @staticmethod
     def from_data(
         *, data: Dict[str, oai.PathItem], schemas: Schemas, config: Config
-    ) -> Tuple[Dict[_PythonIdentifier, "EndpointCollection"], Schemas]:
+    ) -> Tuple[Dict[utils.PythonIdentifier, "EndpointCollection"], Schemas]:
         """Parse the openapi paths data to get EndpointCollections by tag"""
-        endpoints_by_tag: Dict[_PythonIdentifier, EndpointCollection] = {}
+        endpoints_by_tag: Dict[utils.PythonIdentifier, EndpointCollection] = {}
 
         methods = ["get", "put", "post", "delete", "options", "head", "patch", "trace"]
 
@@ -42,7 +41,7 @@ def from_data(
                 operation: Optional[oai.Operation] = getattr(path_data, method)
                 if operation is None:
                     continue
-                tag = to_valid_python_identifier(value=(operation.tags or ["default"])[0], prefix="tag")
+                tag = utils.PythonIdentifier(value=(operation.tags or ["default"])[0], prefix="tag")
                 collection = endpoints_by_tag.setdefault(tag, EndpointCollection(tag=tag))
                 endpoint, schemas = Endpoint.from_data(
                     data=operation, path=path, method=method, tag=tag, schemas=schemas, config=config
@@ -341,7 +340,7 @@ class GeneratorData:
     version: str
     models: Iterator[ModelProperty]
     errors: List[ParseError]
-    endpoint_collections_by_tag: Dict[_PythonIdentifier, EndpointCollection]
+    endpoint_collections_by_tag: Dict[utils.PythonIdentifier, EndpointCollection]
     enums: Iterator[EnumProperty]
 
     @staticmethod

Diff for: openapi_python_client/parser/properties/__init__.py

@@ -21,7 +21,7 @@
 from .converter import convert, convert_chain
 from .enum_property import EnumProperty
 from .model_property import ModelProperty, build_model_property
-from .property import Property, to_valid_python_identifier
+from .property import Property
 from .schemas import Class, Schemas, parse_reference_path, update_schemas_with_data
 
 
@@ -238,7 +238,7 @@ def _string_based_property(
 ) -> Union[StringProperty, DateProperty, DateTimeProperty, FileProperty]:
     """Construct a Property from the type "string" """
     string_format = data.schema_format
-    python_name = to_valid_python_identifier(value=name, prefix=config.field_prefix)
+    python_name = utils.PythonIdentifier(value=name, prefix=config.field_prefix)
     if string_format == "date-time":
         return DateTimeProperty(
             name=name,
@@ -330,7 +330,7 @@ def build_enum_property(
         values=values,
         value_type=value_type,
         default=None,
-        python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+        python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
     )
 
     default = get_enum_default(prop, data)
@@ -378,7 +378,7 @@ def build_union_property(
             default=default,
             inner_properties=sub_properties,
             nullable=data.nullable,
-            python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+            python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
         ),
         schemas,
     )
@@ -401,7 +401,7 @@ def build_list_property(
             default=None,
             inner_property=inner_prop,
             nullable=data.nullable,
-            python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+            python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
         ),
         schemas,
     )
@@ -426,7 +426,7 @@ def _property_from_ref(
         existing,
         required=required,
         name=name,
-        python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+        python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
     )
     if parent:
         prop = attr.evolve(prop, nullable=parent.nullable)
@@ -482,7 +482,7 @@ def _property_from_data(
                 default=convert("float", data.default),
                 required=required,
                 nullable=data.nullable,
-                python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+                python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
             ),
             schemas,
         )
@@ -493,7 +493,7 @@ def _property_from_data(
                 default=convert("int", data.default),
                 required=required,
                 nullable=data.nullable,
-                python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+                python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
             ),
             schemas,
         )
@@ -504,7 +504,7 @@ def _property_from_data(
                 required=required,
                 default=convert("bool", data.default),
                 nullable=data.nullable,
-                python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+                python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
             ),
             schemas,
         )
@@ -523,7 +523,7 @@ def _property_from_data(
                 required=required,
                 nullable=False,
                 default=None,
-                python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+                python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
             ),
             schemas,
         )

Diff for: openapi_python_client/parser/properties/model_property.py

@@ -7,7 +7,7 @@
 from ... import schema as oai
 from ... import utils
 from ..errors import ParseError, PropertyError
-from .property import Property, to_valid_python_identifier
+from .property import Property
 from .schemas import Class, Schemas, parse_reference_path
 
 
@@ -210,7 +210,7 @@ def build_model_property(
         required=required,
         name=name,
         additional_properties=additional_properties,
-        python_name=to_valid_python_identifier(value=name, prefix=config.field_prefix),
+        python_name=utils.PythonIdentifier(value=name, prefix=config.field_prefix),
     )
     if class_info.name in schemas.classes_by_name:
         error = PropertyError(data=data, detail=f'Attempted to generate duplicate models with name "{class_info.name}"')

Diff for: openapi_python_client/parser/properties/property.py

@@ -1,27 +1,11 @@
-from typing import ClassVar, NewType, Optional, Set
+__all__ = ["Property"]
+
+from typing import ClassVar, Optional, Set
 
 import attr
 
 from ... import Config
-from ...utils import fix_keywords, fix_reserved_words, sanitize, snake_case
-
-_PythonIdentifier = NewType("_PythonIdentifier", str)
-
-
-def to_valid_python_identifier(*, value: str, prefix: str) -> _PythonIdentifier:
-    """
-    Given a string, attempt to coerce it into a valid Python identifier by stripping out invalid characters and, if
-    necessary, prepending a prefix.
-
-    See:
-        https://docs.python.org/3/reference/lexical_analysis.html#identifiers
-    """
-    new_value = fix_reserved_words(fix_keywords(snake_case(sanitize(value))))
-
-    if new_value.isidentifier():
-        return _PythonIdentifier(new_value)
-
-    return _PythonIdentifier(f"{prefix}{new_value}")
+from ...utils import PythonIdentifier
 
 
 @attr.s(auto_attribs=True, frozen=True)
@@ -45,13 +29,13 @@ class Property:
     _type_string: ClassVar[str] = ""
     _json_type_string: ClassVar[str] = ""  # Type of the property after JSON serialization
     default: Optional[str] = attr.ib()
-    python_name: _PythonIdentifier
+    python_name: PythonIdentifier
 
     template: ClassVar[Optional[str]] = None
     json_is_dict: ClassVar[bool] = False
 
     def set_python_name(self, new_name: str, config: Config) -> None:
-        object.__setattr__(self, "python_name", to_valid_python_identifier(value=new_name, prefix=config.field_prefix))
+        object.__setattr__(self, "python_name", PythonIdentifier(value=new_name, prefix=config.field_prefix))
 
     def get_base_type_string(self) -> str:
         return self._type_string

Diff for: openapi_python_client/parser/responses.py

@@ -6,9 +6,9 @@
 
 from .. import Config
 from .. import schema as oai
+from ..utils import PythonIdentifier
 from .errors import ParseError, PropertyError
 from .properties import AnyProperty, Property, Schemas, property_from_data
-from .properties.property import to_valid_python_identifier
 
 
 @attr.s(auto_attribs=True, frozen=True)
@@ -37,7 +37,7 @@ def empty_response(*, status_code: int, response_name: str, config: Config) -> R
             default=None,
             nullable=False,
             required=True,
-            python_name=to_valid_python_identifier(value=response_name, prefix=config.field_prefix),
+            python_name=PythonIdentifier(value=response_name, prefix=config.field_prefix),
         ),
         source="None",
     )

Diff for: openapi_python_client/utils.py

@@ -1,11 +1,25 @@
 import builtins
 import re
 from keyword import iskeyword
-from typing import List
+from typing import Any, List
 
 delimiters = " _-"
 
 
+class PythonIdentifier(str):
+    """A string which has been validated / transformed into a valid identifier for Python"""
+
+    def __new__(cls, value: str, prefix: str) -> "PythonIdentifier":
+        new_value = fix_reserved_words(fix_keywords(snake_case(sanitize(value))))
+
+        if not new_value.isidentifier():
+            new_value = f"{prefix}{new_value}"
+        return str.__new__(cls, new_value)
+
+    def __deepcopy__(self, _: Any) -> "PythonIdentifier":
+        return self
+
+
 def sanitize(value: str) -> str:
     """Removes every character that isn't 0-9, A-Z, a-z, or a known delimiter"""
     return re.sub(rf"[^\w{delimiters}]+", "", value)

Diff for: tests/test_parser/test_properties/test_property.py

@@ -1,25 +1,5 @@
-import attr
 import pytest
 
-from openapi_python_client.parser.properties.property import to_valid_python_identifier
-
-
-class TestToValidPythonIdentifier:
-    def test_valid_identifier_is_not_changed(self):
-        assert to_valid_python_identifier(value="valid_field", prefix="field") == "valid_field"
-
-    def test_numbers_are_prefixed(self):
-        assert to_valid_python_identifier(value="1", prefix="field") == "field1"
-
-    def test_invalid_symbols_are_stripped(self):
-        assert to_valid_python_identifier(value="$abc", prefix="prefix") == "abc"
-
-    def test_keywords_are_postfixed(self):
-        assert to_valid_python_identifier(value="for", prefix="prefix") == "for_"
-
-    def test_empty_is_prefixed(self):
-        assert to_valid_python_identifier(value="", prefix="something") == "something"
-
 
 class TestProperty:
     @pytest.mark.parametrize(
@@ -68,8 +48,6 @@ def test_to_string(self, mocker, default, required, expected, property_factory):
         assert p.to_string() == expected
 
     def test_get_imports(self, property_factory):
-        from openapi_python_client.parser.properties import Property
-
         p = property_factory()
         assert p.get_imports(prefix="") == set()
 

Diff for: tests/test_utils.py

@@ -3,6 +3,23 @@
 from openapi_python_client import utils
 
 
+class TestPythonIdentifier:
+    def test_valid_identifier_is_not_changed(self):
+        assert utils.PythonIdentifier(value="valid_field", prefix="field") == "valid_field"
+
+    def test_numbers_are_prefixed(self):
+        assert utils.PythonIdentifier(value="1", prefix="field") == "field1"
+
+    def test_invalid_symbols_are_stripped(self):
+        assert utils.PythonIdentifier(value="$abc", prefix="prefix") == "abc"
+
+    def test_keywords_are_postfixed(self):
+        assert utils.PythonIdentifier(value="for", prefix="prefix") == "for_"
+
+    def test_empty_is_prefixed(self):
+        assert utils.PythonIdentifier(value="", prefix="something") == "something"
+
+
 @pytest.mark.parametrize(
     "before, after",
     [