fix: update render() to return None, fix f-string syntax and variable references

Author: tomdurrant

src/rompy/core/config.py

@@ -45,7 +45,7 @@ class BaseConfig(RompyBaseModel):
     def __call__(self, *args, **kwargs):
         return self
 
-    def render(self, context: dict, output_dir: Path | str) -> str:
+    def render(self, context: dict, output_dir: Path | str):
         """Render the configuration template to the output directory.
 
         This method orchestrates the template rendering process. The default implementation
@@ -63,4 +63,4 @@ def render(self, context: dict, output_dir: Path | str) -> str:
         # Import locally to avoid potential circular imports at module import time
         from rompy.core.render import render as cookiecutter_render
 
-        return cookiecutter_render(context, self.template, output_dir, self.checkout)
+        cookiecutter_render(context, self.template, output_dir, self.checkout)

src/rompy/model.py

@@ -254,10 +254,8 @@ def generate(self) -> str:
             cc_full["config"] = self.config
 
         # Render templates
-        logger.info(
-            f"Rendering model configurations to {self.output_dir}/{self.run_id}..."
-        )
-        staging_dir = self.config.render(cc_full, self.output_dir)
+        logger.info(f"Rendering model configurations to {self.staging_dir}...")
+        self.config.render(cc_full, self.output_dir)
 
         logger.info("")
         # Use the log_box utility function
@@ -268,8 +266,8 @@ def generate(self) -> str:
             logger=logger,
             add_empty_line=False,
         )
-        logger.info(f"Model files generated at: {staging_dir}")
-        return staging_dir
+        logger.info(f"Model files generated at: {self.staging_dir}")
+        return self.staging_dir
 
     def zip(self) -> str:
         """Zip the input files for the model run

tests/test_config_render_delegation.py

@@ -11,7 +11,7 @@ def test_modelrun_delegates_to_config_render(tmp_path):
     class TestConfig(BaseConfig):
         def render(self, context: dict, output_dir):
             # real implementation replaced by mock in the test
-            return str(tmp_path / "staging")
+            pass
 
     config = TestConfig(template="../rompy/templates/base", checkout=None)
     model_run = ModelRun(run_id="test", output_dir=str(tmp_path), config=config)
@@ -21,7 +21,7 @@ def render(self, context: dict, output_dir):
     # the mock was bound to the instance or the class.
     # Patch by import path to avoid binding issues with Pydantic-generated classes
     with unittest.mock.patch.object(
-        TestConfig, "render", return_value=str(tmp_path / "staging")
+        TestConfig, "render", return_value=None
     ) as mock_render:
         # Execute
         result = model_run.generate()
@@ -43,4 +43,4 @@ def render(self, context: dict, output_dir):
         assert "runtime" in context_arg
         assert "config" in context_arg
         assert output_dir_arg == model_run.output_dir
-        assert result == str(tmp_path / "staging")
+        assert str(result) == str(tmp_path / "test")