Fix bad code generation (#1360)

I've had some issues with the code generation.
This should fix:
- missing parenthesis in to_multipart
 #1338 #1318
- missing imports in the lazy eval in to_multipart:
#931 and #1051

---------

Co-authored-by: Eric Yen <[email protected]>

Author: EricAtORS

.changeset/fix_bad_code_generation.md

@@ -0,0 +1,13 @@
+---
+default: patch
+---
+
+# Fix bad code generation
+
+#1360 by @EricAtORS
+
+This fixes:
+- missing parenthesis in to_multipart
+ #1338 #1318
+- missing imports in the lazy eval in to_multipart:
+#931 and #1051

end_to_end_tests/golden-record/my_test_api_client/models/body_upload_file_tests_upload_post.py

@@ -172,6 +172,10 @@ def to_dict(self) -> dict[str, Any]:
         return field_dict
 
     def to_multipart(self) -> types.RequestFiles:
+        from ..models.body_upload_file_tests_upload_post_some_nullable_object import (
+            BodyUploadFileTestsUploadPostSomeNullableObject,
+        )
+
         files: types.RequestFiles = []
 
         files.append(("some_file", self.some_file.to_tuple()))

openapi_python_client/templates/model.py.jinja

@@ -151,6 +151,9 @@ return field_dict
 
 {% if model.is_multipart_body %}
     def to_multipart(self) -> types.RequestFiles:
+    {% for lazy_import in model.lazy_imports %}
+        {{ lazy_import }}
+    {% endfor %}
         files: types.RequestFiles = []
 
         {% for property in model.required_properties + model.optional_properties %}

openapi_python_client/templates/property_templates/uuid_property.py.jinja

@@ -29,5 +29,5 @@ if not isinstance({{ source }}, Unset):
 {% endmacro %}
 
 {% macro multipart(property, source, name) %}
-files.append(({{ name }}, (None, str({{ source }}), "text/plain"))
+files.append(({{ name }}, (None, str({{ source }}), "text/plain")))
 {% endmacro %}

tests/test_templates/test_property_templates/test_uuid_property/__init__.py

@@ -0,0 +1 @@
+"""Tests for UUID property templates."""

tests/test_templates/test_property_templates/test_uuid_property/test_uuid_multipart.py

@@ -0,0 +1,70 @@
+"""Tests for UUID property multipart macro functionality."""
+
+from pathlib import Path
+from typing import Any
+from uuid import UUID
+
+import jinja2
+import pytest
+
+from openapi_python_client.parser.properties import UuidProperty
+from openapi_python_client.utils import PythonIdentifier
+
+
+def uuid_property(required: bool = True, default: Any = None) -> UuidProperty:
+    """Helper to create a UuidProperty for testing."""
+    return UuidProperty(
+        name="test_uuid",
+        required=required,
+        default=default,
+        python_name=PythonIdentifier(value="test_uuid", prefix=""),
+        description="A test UUID property",
+        example="550e8400-e29b-41d4-a716-446655440000",
+    )
+
+
+@pytest.fixture
+def jinja_env() -> jinja2.Environment:
+    """Create a Jinja2 environment with the property templates loaded."""
+    templates_dir = Path(__file__).parent.parent.parent.parent.parent / "openapi_python_client" / "templates"
+    env = jinja2.Environment(
+        loader=jinja2.FileSystemLoader(templates_dir),
+        trim_blocks=True,
+        lstrip_blocks=True,
+    )
+    return env
+
+
+def test_multipart_macro_generates_syntactically_correct_code_for_required_uuid(jinja_env: jinja2.Environment) -> None:
+    """Test that the multipart macro generates syntactically correct Python code for required UUID properties."""
+    prop = uuid_property(required=True)
+
+    template = jinja_env.get_template("property_templates/uuid_property.py.jinja")
+
+    # Render the multipart macro
+    multipart_code = template.module.multipart(prop, "test_uuid", '"test_uuid"')  # type: ignore[attr-defined]
+
+    # Verify the generated code is syntactically correct
+    expected = 'files.append(("test_uuid", (None, str(test_uuid), "text/plain")))'
+    assert multipart_code.strip() == expected
+
+    # Verify it compiles as valid Python
+    compile(multipart_code, "<string>", "exec")
+
+
+def test_multipart_macro_generates_syntactically_correct_code_for_optional_uuid(jinja_env: jinja2.Environment) -> None:
+    """Test that the multipart macro generates syntactically correct Python code for optional UUID properties."""
+    prop = uuid_property(required=False)
+
+    template = jinja_env.get_template("property_templates/uuid_property.py.jinja")
+
+    # Render the multipart macro
+    multipart_code = template.module.multipart(prop, "test_uuid", '"test_uuid"')  # type: ignore[attr-defined]
+
+    # Verify the generated code is syntactically correct
+    expected = 'files.append(("test_uuid", (None, str(test_uuid), "text/plain")))'
+    assert multipart_code.strip() == expected
+
+    # Verify it compiles as valid Python
+    compile(multipart_code, "<string>", "exec")
+