(fix): support generating correct code snippets when extending base c…

…lient in python (#3097)

* fix

* (fix): support generating accurate code snippets when writing to base_client.py

* specify changelog

* fix check

generators/python/sdk/CHANGELOG.md

@@ -5,6 +5,42 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.11.8-rc0] - 2024-02-27
+
+- Beta: Introduce a `client` custom config that allows you to specify class_name and 
+  filename for the client. This configuration can be used in several ways: 
+
+  1. Rename your client class:
+
+     ```yml
+     config: 
+       client: 
+         class_name: Imdb
+     ```
+  
+  2. Add custom functions to your generated SDK:
+     
+     ```yml
+     config: 
+       client: 
+         class_name: BaseImdb
+         filename: base_client.py
+         exported_class_name: Imdb
+         exported_filename: client.py
+     ```
+
+     Often times you may want to add additional methods or utilites to the 
+     generated client. The easiest way to do this is to configure Fern to write
+     the autogenerated client in another file and extend it on your own. 
+
+     With the configuration above, Fern's Python SDK generator will create a 
+     class called `BaseImdb` and `AsyncBaseImdb` and put them in a file called 
+     `base_client.py`. As a user, you can extend both these classes with 
+     custom utilities. 
+
+     To make sure the code snippets in the generated SDK are accurate you can 
+     specify `exported_class_name` and `exported_filename`. 
+
 ## [0.11.7] - 2024-02-27
 
 - Improvement: Introduces a flag `use_str_enums` to swap from using proper Enum classes to using Literals to represent enums. This change allows for forward compatibility of enums, since the user will receive the string back.

generators/python/sdk/VERSION

@@ -1 +1 @@
-0.11.7
+0.11.8-rc0

generators/python/src/fern_python/generators/sdk/client_generator/root_client_generator.py

@@ -97,12 +97,13 @@ def __init__(
         self._snippet_writer = snippet_writer
 
     def generate(self, source_file: SourceFile) -> GeneratedRootClient:
+        exported_client_class_name = self._context.get_class_name_for_exported_root_client()
         builder = RootClientGenerator.GeneratedRootClientBuilder(
             module_path=self._context.get_module_path_in_project(
-                self._context.get_filepath_for_root_client().to_module().path
+                self._context.get_filepath_for_exported_root_client().to_module().path
             ),
-            class_name=self._class_name,
-            async_class_name=self._async_class_name,
+            class_name=self._context.get_class_name_for_exported_root_client(),
+            async_class_name="Async" + exported_client_class_name,
             constructor_parameters=self._client_wrapper_constructor_params,
         )
         generated_root_client = builder.build()

generators/python/src/fern_python/generators/sdk/context/sdk_generator_context.py

@@ -89,11 +89,19 @@ def get_class_name_of_async_subpackage_service(self, subpackage_id: ir_types.Sub
         ...
 
     @abstractmethod
-    def get_filepath_for_root_client(self) -> Filepath:
+    def get_filepath_for_generated_root_client(self) -> Filepath:
         ...
 
     @abstractmethod
-    def get_class_name_for_root_client(self) -> str:
+    def get_class_name_for_generated_root_client(self) -> str:
+        ...
+
+    @abstractmethod
+    def get_filepath_for_exported_root_client(self) -> Filepath:
+        ...
+
+    @abstractmethod
+    def get_class_name_for_exported_root_client(self) -> str:
         ...
 
     @abstractmethod

generators/python/src/fern_python/generators/sdk/context/sdk_generator_context_impl.py

@@ -34,24 +34,33 @@ def __init__(
             custom_config=custom_config,
             project_module_path=project_module_path,
         )
-        client_class_name = custom_config.client_class_name or (
-            pascal_case(generator_config.organization) + pascal_case(generator_config.workspace_name)
+        client_class_name = (
+            custom_config.client_class_name
+            or custom_config.client.class_name
+            or (pascal_case(generator_config.organization) + pascal_case(generator_config.workspace_name))
         )
+        exported_client_class_name = custom_config.client.exported_class_name or client_class_name
+        client_filename = custom_config.client_filename or custom_config.client.filename
         self._error_declaration_referencer = ErrorDeclarationReferencer(
             skip_resources_module=custom_config.improved_imports
         )
         self._environments_enum_declaration_referencer = EnvironmentsEnumDeclarationReferencer(
-            client_class_name=client_class_name, skip_resources_module=custom_config.improved_imports
+            client_class_name=exported_client_class_name, skip_resources_module=custom_config.improved_imports
         )
         self._subpackage_client_declaration_referencer = SubpackageClientDeclarationReferencer(
             skip_resources_module=custom_config.improved_imports
         )
         self._subpackage_async_client_declaration_referencer = SubpackageAsyncClientDeclarationReferencer(
             skip_resources_module=custom_config.improved_imports
         )
-        self._root_client_declaration_referencer = RootClientDeclarationReferencer(
-            root_class_name=client_class_name,
-            root_client_filename=custom_config.client_filename,
+        self._root_generated_client_declaration_referencer = RootClientDeclarationReferencer(
+            client_class_name=client_class_name,
+            client_filename=client_filename,
+            skip_resources_module=custom_config.improved_imports,
+        )
+        self._root_exported_client_declaration_referencer = RootClientDeclarationReferencer(
+            client_class_name=exported_client_class_name,
+            client_filename=custom_config.client.exported_filename or client_filename,
             skip_resources_module=custom_config.improved_imports,
         )
         self._custom_config = custom_config
@@ -90,11 +99,17 @@ def get_reference_to_subpackage_service(self, subpackage_id: ir_types.Subpackage
         subpackage = self.ir.subpackages[subpackage_id]
         return self._subpackage_client_declaration_referencer.get_class_reference(name=subpackage)
 
-    def get_filepath_for_root_client(self) -> Filepath:
-        return self._root_client_declaration_referencer.get_filepath(name=None)
+    def get_filepath_for_generated_root_client(self) -> Filepath:
+        return self._root_generated_client_declaration_referencer.get_filepath(name=None)
+
+    def get_class_name_for_generated_root_client(self) -> str:
+        return self._root_generated_client_declaration_referencer.get_class_name(name=None)
+
+    def get_filepath_for_exported_root_client(self) -> Filepath:
+        return self._root_exported_client_declaration_referencer.get_filepath(name=None)
 
-    def get_class_name_for_root_client(self) -> str:
-        return self._root_client_declaration_referencer.get_class_name(name=None)
+    def get_class_name_for_exported_root_client(self) -> str:
+        return self._root_exported_client_declaration_referencer.get_class_name(name=None)
 
     def get_filepath_for_async_subpackage_service(self, subpackage_id: ir_types.SubpackageId) -> Filepath:
         subpackage = self.ir.subpackages[subpackage_id]

generators/python/src/fern_python/generators/sdk/custom_config.py

@@ -14,11 +14,24 @@ class SdkPydanticModelCustomConfig(PydanticModelCustomConfig):
     require_optional_fields: bool = False
 
 
+class ClientConfiguration(pydantic.BaseModel):
+    # The filename where the auto-generated client
+    # lives
+    filename: str = "client.py"
+    class_name: Optional[str] = None
+    # The filename of the exported client which
+    # will be used in code snippets
+    exported_filename: str = "client.py"
+    exported_class_name: Optional[str] = None
+
+    class Config:
+        extra = pydantic.Extra.forbid
+
+
 class SDKCustomConfig(pydantic.BaseModel):
     extra_dependencies: Dict[str, str] = {}
     skip_formatting: bool = False
-    client_class_name: Optional[str] = None
-    client_filename: str = "client.py"
+    client: ClientConfiguration = ClientConfiguration()
     include_union_utils: bool = False
     use_api_name_in_package: bool = False
     package_name: Optional[str] = None
@@ -30,5 +43,10 @@ class SDKCustomConfig(pydantic.BaseModel):
     # Python SDK by removing nested `resources` directoy
     improved_imports: bool = False
 
+    # deprecated, use client config instead
+    client_class_name: Optional[str] = None
+    # deprecated, use client config instead
+    client_filename: Optional[str] = None
+
     class Config:
         extra = pydantic.Extra.forbid

generators/python/src/fern_python/generators/sdk/declaration_referencers/root_client_declaration_referencer.py

@@ -4,16 +4,17 @@
 
 
 class RootClientDeclarationReferencer(SdkDeclarationReferencer[None]):
-    def __init__(self, root_class_name: str, root_client_filename: str, skip_resources_module: bool):
+    def __init__(self, client_class_name: str, client_filename: str, skip_resources_module: bool):
         super().__init__(skip_resources_module=skip_resources_module)
-        self._root_class_name = root_class_name
-        self._root_client_filename = root_client_filename
+        self._client_class_name = client_class_name
+        self._client_filename = client_filename
 
     def get_filepath(self, *, name: None) -> Filepath:
         return Filepath(
             directories=(),
-            file=Filepath.FilepathPart(module_name=self._root_client_filename[:-3]),
+            # the [:-3] removes the .py extension
+            file=Filepath.FilepathPart(module_name=self._client_filename[:-3]),
         )
 
     def get_class_name(self, *, name: None) -> str:
-        return self._root_class_name
+        return self._client_class_name

generators/python/src/fern_python/generators/sdk/sdk_generator.py

@@ -69,9 +69,15 @@ def run(
     ) -> None:
         custom_config = SDKCustomConfig.parse_obj(generator_config.custom_config or {})
 
-        if not custom_config.client_filename.endswith(".py"):
+        if custom_config.client_filename is not None and not custom_config.client_filename.endswith(".py"):
             raise RuntimeError("client_filename must end in .py")
 
+        if not custom_config.client.filename.endswith(".py"):
+            raise RuntimeError("client_location.filename must end in .py")
+
+        if not custom_config.client.exported_filename.endswith(".py"):
+            raise RuntimeError("client_location.exported_filename must end in .py")
+
         for dep, version in custom_config.extra_dependencies.items():
             project.add_dependency(dependency=AST.Dependency(name=dep, version=version))
 
@@ -225,16 +231,16 @@ def _generate_root_client(
         snippet_registry: SnippetRegistry,
         snippet_writer: SnippetWriter,
     ) -> GeneratedRootClient:
-        filepath = context.get_filepath_for_root_client()
+        filepath = context.get_filepath_for_generated_root_client()
         source_file = SourceFileFactory.create(
             project=project, filepath=filepath, generator_exec_wrapper=generator_exec_wrapper
         )
         generated_root_client = RootClientGenerator(
             context=context,
             package=ir.root_package,
             generated_environment=generated_environment,
-            class_name=context.get_class_name_for_root_client(),
-            async_class_name="Async" + context.get_class_name_for_root_client(),
+            class_name=context.get_class_name_for_generated_root_client(),
+            async_class_name="Async" + context.get_class_name_for_generated_root_client(),
             snippet_registry=snippet_registry,
             snippet_writer=snippet_writer,
         ).generate(source_file=source_file)