Allow inputs to have configurable base class (#371)

The configuration in the pyproject.toml now takes the additional setting
ignore_extra_fields. ignore_extra_fields is true by default as BaseModel
ignores extra fields by default. If it is set to false, extra='forbid'
will be appended to the BaseModel in the client. If additional fields
are then provided, an error is thrown.

Additionally three unit tests have been added, which test:
- If extra='forbid' is properly appended if no extra is provided
- If extra='ignore' is not overriden, in case it exists
- If other classes in the provided code are left untouched

Author: luci-bytes

ariadne_codegen/client_generators/package.py

@@ -13,7 +13,12 @@
 from ..exceptions import ParsingError
 from ..plugins.manager import PluginManager
 from ..settings import ClientSettings, CommentsStrategy
-from ..utils import ast_to_str, process_name, str_to_pascal_case
+from ..utils import (
+    add_extra_to_base_model,
+    ast_to_str,
+    process_name,
+    str_to_pascal_case,
+)
 from .arguments import ArgumentsGenerator
 from .client import ClientGenerator
 from .comments import get_comment
@@ -85,6 +90,7 @@ def __init__(
         plugin_manager: Optional[PluginManager] = None,
         enable_custom_operations: bool = False,
         include_typename: bool = True,
+        ignore_extra_fields: bool = True,
     ) -> None:
         self.package_path = Path(target_path) / package_name
 
@@ -135,6 +141,7 @@ def __init__(
         self.custom_scalars = custom_scalars if custom_scalars else {}
         self.plugin_manager = plugin_manager
         self.include_typename = include_typename
+        self.ignore_extra_fields = ignore_extra_fields
 
         self._result_types_files: Dict[str, ast.Module] = {}
         self._generated_files: List[str] = []
@@ -355,6 +362,8 @@ def _copy_files(self):
         ]
         for source_path in files_to_copy:
             code = self._add_comments_to_code(source_path.read_text(encoding="utf-8"))
+            if not self.ignore_extra_fields and source_path.name == "base_model.py":
+                code = add_extra_to_base_model(code)
             if self.plugin_manager:
                 code = self.plugin_manager.copy_code(code)
             target_path = self.package_path / source_path.name
@@ -538,4 +547,5 @@ def get_package_generator(
         plugin_manager=plugin_manager,
         enable_custom_operations=settings.enable_custom_operations,
         include_typename=settings.include_typename,
+        ignore_extra_fields=settings.ignore_extra_fields,
     )

ariadne_codegen/settings.py

@@ -74,6 +74,7 @@ class ClientSettings(BaseSettings):
     files_to_include: List[str] = field(default_factory=list)
     scalars: Dict[str, ScalarData] = field(default_factory=dict)
     include_typename: bool = True
+    ignore_extra_fields: bool = True
 
     def __post_init__(self):
         if not self.queries_path and not self.enable_custom_operations:

ariadne_codegen/utils.py

@@ -138,3 +138,29 @@ def process_name(
     if set(name) == {"_"} and not processed_name:
         return "underscore_named_field_"
     return processed_name
+
+
+def add_extra_to_base_model(code: str) -> str:
+    "Adds `extra='forbid'` to the ConfigDict in BaseModel if not already present."
+    tree = ast.parse(code)
+    for node in tree.body:
+        if not isinstance(node, ast.ClassDef):
+            continue
+        if node.name != "BaseModel":
+            continue
+        for statement in node.body:
+            if not isinstance(statement, ast.Assign):
+                continue
+            call = statement.value
+            if not isinstance(call, ast.Call):
+                continue
+            if not isinstance(call.func, ast.Name):
+                continue
+            if call.func.id != "ConfigDict":
+                continue
+            if not any(kw.arg == "extra" for kw in call.keywords):
+                call.keywords.append(
+                    ast.keyword(arg="extra", value=ast.Constant("forbid"))
+                )
+    ast.fix_missing_locations(tree)
+    return ast.unparse(tree)

tests/test_utils.py

@@ -4,6 +4,7 @@
 import pytest
 
 from ariadne_codegen.utils import (
+    add_extra_to_base_model,
     ast_to_str,
     convert_to_multiline_string,
     format_multiline_strings,
@@ -201,3 +202,42 @@ def test_process_name_returns_name_returned_from_plugin_for_name_with_only_under
         )
         == "name_from_plugin"
     )
+
+
+def test_adds_extra_to_base_model_if_missing():
+    code = dedent("""
+        class BaseModel:
+            Config = ConfigDict()
+    """)
+    expected = dedent("""
+        class BaseModel:
+            Config = ConfigDict(extra='forbid')
+    """)
+    result = add_extra_to_base_model(code)
+    assert dedent(result).strip() == expected.strip()
+
+
+def test_adds_extra_to_base_model_does_not_overwrite_existing_extra():
+    code = dedent("""
+        class BaseModel:
+            Config = ConfigDict(extra='ignore')
+    """)
+    expected = dedent("""
+        class BaseModel:
+            Config = ConfigDict(extra='ignore')
+    """)
+    result = add_extra_to_base_model(code)
+    assert dedent(result).strip() == expected.strip()
+
+
+def test_adds_extra_to_base_model_leaves_other_classes_untouched():
+    code = dedent("""
+        class NotBaseModel:
+            Config = ConfigDict()
+    """)
+    expected = dedent("""
+        class NotBaseModel:
+            Config = ConfigDict()
+    """)
+    result = add_extra_to_base_model(code)
+    assert dedent(result).strip() == expected.strip()