Repository: mirumee/ariadne-codegen (python)
Issue: Load of module and client extremely slow.
## Description

I have a fairly complex GraphQL repository running on Hasura, that might have hundreds if not thousands of types and definitions. Right now I implemented this library for some specific queries and use cases, and all of those types available in the server are not needed for the execution of my isolated use case.

The generated code, creates a `__init__.py` file where everything is imported on package load. This `__init__.py` file is easily 4k lines of code, generating thousands of imports. Loading the `client` module might easily take minutes and GBs of RAM due to this reason. So I went ahead and deleted everything from the `__init__.py` and left it empty, as the calls to the right types happen on a module by module basis. This reduced my loading time from minutes to miliseconds, and the application still works as expected.

Now the question: is there a reason to import absolutely everything on the `__init__.py`?  For big and complex schemas is an overkill, and increases the application loading time by minutes. Should this file be empty and do a module by module import? - if that is the case, is this not already happening in the current implementation?

Maybe I am missing something, and I greatly appreciate your time and consideration.
Pull request description: No reimports plugin
This pr adds `NoReimportsPlugin` which removes the content of generated `__init__.py`.

resolves #233 

Patch:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 928a2b0..7810768 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## UNRELEASED
 
 - Removed `model_rebuild` calls for generated input, fragment and result models. 
+- Added `NoReimportsPlugin` that makes the `__init__.py` of generated client package empty.
 
 
 ## 0.10.0 (2023-11-15)
diff --git a/README.md b/README.md
index 6c13452..56fb84b 100644
--- a/README.md
+++ b/README.md
@@ -103,6 +103,8 @@ plugins = ["ariadne_codegen.contrib.extract_operations.ExtractOperationsPlugin"]
 operations_module_name = "custom_operations_module_name"
 ```
 
+- [`ariadne_codegen.contrib.extract_operations.NoReimportsPlugin`](ariadne_codegen/contrib/no_reimports.py) - This plugin removes content of generated `__init__.py`. This is useful in scenarios where generated plugins contain so many Pydantic models that client's eager initialization of entire package on first import is very slow.
+
 
 ## Using generated client
 
diff --git a/ariadne_codegen/contrib/__init__.py b/ariadne_codegen/contrib/__init__.py
index dcdd284..63e5565 100644
--- a/ariadne_codegen/contrib/__init__.py
+++ b/ariadne_codegen/contrib/__init__.py
@@ -1,4 +1,5 @@
 from .extract_operations import ExtractOperationsPlugin
+from .no_reimports import NoReimportsPlugin
 from .shorter_results import ShorterResultsPlugin
 
-__all__ = ["ExtractOperationsPlugin", "ShorterResultsPlugin"]
+__all__ = ["ExtractOperationsPlugin", "NoReimportsPlugin", "ShorterResultsPlugin"]
diff --git a/ariadne_codegen/contrib/extract_operations.py b/ariadne_codegen/contrib/extract_operations.py
index 45abe3f..7f14633 100644
--- a/ariadne_codegen/contrib/extract_operations.py
+++ b/ariadne_codegen/contrib/extract_operations.py
@@ -41,24 +41,25 @@ class ExtractOperationsPlugin(Plugin):
         self._operations_variables: Dict[str, str] = {}
 
     def generate_init_module(self, module: ast.Module) -> ast.Module:
-        variables_names = list(self._operations_variables.values())
-        module.body.insert(
-            0,
-            generate_import_from(
-                names=variables_names,
-                from_=self.operations_module_name,
-                level=1,
-            ),
-        )
-        all_assign = cast(ast.Assign, module.body[-1])
-        already_imported_names = [
-            cast(ast.Constant, const).value
-            for const in cast(ast.List, all_assign.value).elts
-        ]
-        cast(ast.List, all_assign.value).elts = [
-            generate_constant(name)
-            for name in sorted(already_imported_names + variables_names)
-        ]
+        if module.body:
+            variables_names = list(self._operations_variables.values())
+            module.body.insert(
+                0,
+                generate_import_from(
+                    names=variables_names,
+                    from_=self.operations_module_name,
+                    level=1,
+                ),
+            )
+            all_assign = cast(ast.Assign, module.body[-1])
+            already_imported_names = [
+                cast(ast.Constant, const).value
+                for const in cast(ast.List, all_assign.value).elts
+            ]
+            cast(ast.List, all_assign.value).elts = [
+                generate_constant(name)
+                for name in sorted(already_imported_names + variables_names)
+            ]
 
         self._generate_operations_module()
         return ast.fix_missing_locations(module)
diff --git a/ariadne_codegen/contrib/no_reimports.py b/ariadne_codegen/contrib/no_reimports.py
new file mode 100644
index 0000000..9d4ae94
--- /dev/null
+++ b/ariadne_codegen/contrib/no_reimports.py
@@ -0,0 +1,9 @@
+import ast
+
+from ariadne_codegen.plugins.base import Plugin
+
+
+class NoReimportsPlugin(Plugin):
+    def generate_init_module(self, module: ast.Module) -> ast.Module:
+        module.body = []
+        return module


Test patch:
diff --git a/tests/contrib/test_extract_operations.py b/tests/contrib/test_extract_operations.py
index 395c1ad..0521488 100644
--- a/tests/contrib/test_extract_operations.py
+++ b/tests/contrib/test_extract_operations.py
@@ -87,6 +87,14 @@ def test_generate_init_module_returns_module_with_added_import(
     )
 
 
+def test_generate_init_module_doesnt_add_import_if_module_has_no_body(config_dict):
+    plugin = ExtractOperationsPlugin(schema=None, config_dict=config_dict)
+
+    modified_module = plugin.generate_init_module(ast.Module(body=[], type_ignores=[]))
+
+    assert not modified_module.body
+
+
 def test_generate_init_module_creates_operations_file(config_dict, empty_init_module):
     node = parse("query testXyz { xyz }").definitions[0]
     plugin = ExtractOperationsPlugin(schema=None, config_dict=config_dict)
diff --git a/tests/contrib/test_no_reimports.py b/tests/contrib/test_no_reimports.py
new file mode 100644
index 0000000..0d72478
--- /dev/null
+++ b/tests/contrib/test_no_reimports.py
@@ -0,0 +1,32 @@
+import ast
+
+import pytest
+
+from ariadne_codegen.contrib.no_reimports import NoReimportsPlugin
+
+
+@pytest.mark.parametrize(
+    "module",
+    [
+        ast.Module(
+            body=[
+                ast.ImportFrom(
+                    module="input_types", names=[ast.alias(name="InputA")], level=1
+                ),
+                ast.Assign(
+                    targets=[ast.Name(id="__all__")],
+                    value=ast.List(elts=[ast.Constant(value="InputA")]),
+                ),
+            ],
+            type_ignores=[],
+        ),
+        ast.Module(body=[], type_ignores=[]),
+    ],
+)
+def test_generate_init_module_returns_module_without_body(module):
+    plugin = NoReimportsPlugin(schema=None, config_dict={})
+
+    modified_module = plugin.generate_init_module(module)
+
+    assert isinstance(modified_module, ast.Module)
+    assert not modified_module.body