Fix README and AsyncGenerator imports

Author: AdrienVannson

README.md

@@ -538,10 +538,14 @@ protoc \
 
 ### Using grpcio library instead of grpclib
 
-In order to use the `grpcio` library instead of `grpclib`, you can use the `--custom_opt=grpcio`
+In order to use the `grpcio` library instead of `grpclib`, you can use the `--custom_opt=USE_GRPCIO`
 option when running the `protoc` command. 
 This will generate stubs compatible with the `grpcio` library.
 
+Example:
+```sh
+protoc --custom_opt=USE_GRPCIO -I . --custom_out=generated --plugin=protoc-gen-custom=src/betterproto/plugin/main.py demo.proto
+```
 ### TODO
 
 - [x] Fixed length fields

src/betterproto/plugin/typing_compiler.py

@@ -41,6 +41,10 @@ def async_iterable(self, type: str) -> str:
     def async_iterator(self, type: str) -> str:
         raise NotImplementedError()
 
+    @abc.abstractmethod
+    def async_generator(self, type: str) -> str:
+        raise NotImplementedError()
+
     @abc.abstractmethod
     def imports(self) -> Dict[str, Optional[Set[str]]]:
         """
@@ -93,6 +97,10 @@ def async_iterator(self, type: str) -> str:
         self._imports["typing"].add("AsyncIterator")
         return f"AsyncIterator[{type}]"
 
+    def async_generator(self, type: str) -> str:
+        self._imports["typing"].add("AsyncGenerator")
+        return f"AsyncGenerator[{type}, None]"
+
     def imports(self) -> Dict[str, Optional[Set[str]]]:
         return {k: v if v else None for k, v in self._imports.items()}
 
@@ -129,6 +137,10 @@ def async_iterator(self, type: str) -> str:
         self._imported = True
         return f"typing.AsyncIterator[{type}]"
 
+    def async_generator(self, type: str) -> str:
+        self._imported = True
+        return f"typing.AsyncGenerator[{type}, None]"
+
     def imports(self) -> Dict[str, Optional[Set[str]]]:
         if self._imported:
             return {"typing": None}
@@ -169,5 +181,9 @@ def async_iterator(self, type: str) -> str:
         self._imports["collections.abc"].add("AsyncIterator")
         return f'"AsyncIterator[{type}]"'
 
+    def async_generator(self, type: str) -> str:
+        self._imports["collections.abc"].add("AsyncGenerator")
+        return f'"AsyncGenerator[{type}, None]"'
+
     def imports(self) -> Dict[str, Optional[Set[str]]]:
         return {k: v if v else None for k, v in self._imports.items()}

src/betterproto/templates/header.py.j2

@@ -13,6 +13,9 @@ __all__ = (
     {%- for service in output_file.services -%}
         "{{ service.py_name }}Stub",
         "{{ service.py_name }}Base",
+        {%- if output_file.use_grpcio -%}
+        "add_{{ service.py_name }}Servicer_to_server",
+        {%- endif -%}
     {%- endfor -%}
 )
 
@@ -29,7 +32,7 @@ from dataclasses import dataclass
 {% if output_file.datetime_imports %}
 from datetime import {% for i in output_file.datetime_imports|sort %}{{ i }}{% if not loop.last %}, {% endif %}{% endfor %}
 
-{% endif%}
+{% endif %}
 {% set typing_imports = output_file.typing_compiler.imports() %}
 {% if typing_imports %}
 {% for line in output_file.typing_compiler.import_lines() %}

src/betterproto/templates/template.py.j2

@@ -133,7 +133,6 @@ class {{ service.py_name }}Stub(betterproto.ServiceStub):
             metadata=metadata,
         )
                 {% else %}
-        # unary_unary pour grpcio - direct call
         return await self.channel.unary_unary(
             "{{ method.route }}",
             request_serializer={{ method.py_input_message_type }}.SerializeToString,
@@ -284,16 +283,20 @@ class {{ service.py_name }}Base(ServiceBase):
 
     {% endif %}
 
+    @property
+    def __proto_path__(self) -> str:
+        return "{% if output_file.package %}{{ output_file.package }}.{% endif %}{{ service.proto_name }}"
+
     {% for method in service.methods %}
     async def {{ method.py_name }}(self
         {%- if not method.client_streaming -%}
             , request: "{{ method.py_input_message_type }}"
         {%- else -%}
             {# Client streaming: need a request iterator instead #}
-            , request_iterator: AsyncIterator["{{ method.py_input_message_type }}"]
+            , request_iterator: "{{ output_file.typing_compiler.async_iterator(method.py_input_message_type) }}"
         {%- endif -%}
             , context: grpc.aio.ServicerContext
-            ) -> {% if method.server_streaming %}AsyncGenerator["{{ method.py_output_message_type }}", None]{% else %}"{{ method.py_output_message_type }}"{% endif %}:
+            ) -> {% if method.server_streaming %}"{{ output_file.typing_compiler.async_generator(method.py_output_message_type) }}"{% else %}"{{ method.py_output_message_type }}"{% endif %}:
         {% if method.comment %}
 {{ method.comment }}
 

tests/test_typing_compiler.py

@@ -27,6 +27,7 @@ def test_direct_import_typing_compiler():
         "typing": {"Optional", "List", "Dict", "Union", "Iterable", "AsyncIterable"}
     }
     assert compiler.async_iterator("str") == "AsyncIterator[str]"
+    assert compiler.async_generator("str") == "AsyncGenerator[str, None]"
     assert compiler.imports() == {
         "typing": {
             "Optional",
@@ -36,6 +37,7 @@ def test_direct_import_typing_compiler():
             "Iterable",
             "AsyncIterable",
             "AsyncIterator",
+            "AsyncGenerator",
         }
     }
 
@@ -57,6 +59,8 @@ def test_typing_import_typing_compiler():
     assert compiler.imports() == {"typing": None}
     assert compiler.async_iterator("str") == "typing.AsyncIterator[str]"
     assert compiler.imports() == {"typing": None}
+    assert compiler.async_generator("str") == "typing.AsyncGenerator[str, None]"
+    assert compiler.imports() == {"typing": None}
 
 
 def test_no_typing_311_typing_compiler():
@@ -73,6 +77,7 @@ def test_no_typing_311_typing_compiler():
     assert compiler.iterable("str") == '"Iterable[str]"'
     assert compiler.async_iterable("str") == '"AsyncIterable[str]"'
     assert compiler.async_iterator("str") == '"AsyncIterator[str]"'
+    assert compiler.async_generator("str") == '"AsyncGenerator[str, None]"'
     assert compiler.imports() == {
-        "collections.abc": {"Iterable", "AsyncIterable", "AsyncIterator"}
+        "collections.abc": {"Iterable", "AsyncIterable", "AsyncIterator", "AsyncGenerator"}
     }