component parser typing (#561)

Category: typing
JIRA issue: https://jira.ihme.washington.edu/browse/MIC-5648

Changes and notes
typing

Testing
Ran mypy and pytest.

Author: hussain-jafari

CHANGELOG.rst

@@ -1,3 +1,7 @@
+**3.2.11 - 12/23/24**
+
+  - Type-hinting: Fix mypy errors in vivarium/framework/components/parser.py
+
 **3.2.10 - 12/17/24**
 
   - Type-hinting: Fix mypy errors in vivarium/framework/components/manager.py

docs/nitpick-exceptions

@@ -42,6 +42,7 @@ py:class PandasObject
 py:class DataFrameGroupBy
 py:class ResultsFormatter
 py:class ResultsUpdater
+py:class _NestedDict
 py:exc ResultsConfigurationError
 py:exc vivarium.framework.results.exceptions.ResultsConfigurationError
 

pyproject.toml

@@ -44,7 +44,6 @@ exclude = [
     'src/vivarium/examples/disease_model/observer.py',
     'src/vivarium/examples/disease_model/population.py',
     'src/vivarium/examples/disease_model/risk.py',
-    'src/vivarium/framework/components/parser.py',
     'src/vivarium/framework/engine.py',
     'src/vivarium/framework/population/manager.py',
     'src/vivarium/framework/population/population_view.py',

src/vivarium/framework/components/parser.py

@@ -1,4 +1,3 @@
-# mypy: ignore-errors
 """
 ==================================
 The Component Configuration Parser
@@ -22,13 +21,17 @@
 
 """
 
+from typing import Union
+
 from layered_config_tree.main import LayeredConfigTree
 
 from vivarium.framework.utilities import import_by_path
 
 from ... import Component
 from .manager import ComponentConfigError
 
+_NestedDict = dict[str, Union[str, list[str], "_NestedDict"]]
+
 
 class ParsingError(ComponentConfigError):
     """Error raised when component configurations are not specified correctly."""
@@ -117,7 +120,7 @@ def parse_component_config(self, component_config: LayeredConfigTree) -> list[Co
         return self.process_level(component_config.to_dict(), [])
 
     def process_level(
-        self, level: str | list[str] | dict[str, dict | list], prefix: list[str]
+        self, level: str | list[str] | _NestedDict, prefix: list[str]
     ) -> list[Component]:
         """Helper function for parsing hierarchical component configuration into a
         flat list of Components.
@@ -173,8 +176,8 @@ def process_level(
                 component_list.extend(components)
         elif isinstance(level, list):
             for child in level:
-                component = self.process_level(child, prefix)
-                component_list.extend(component)
+                component_from_list = self.process_level(child, prefix)
+                component_list.extend(component_from_list)
         elif isinstance(level, str):
             component = self.create_component_from_string(".".join(prefix + [level]))
             component_list.append(component)
@@ -206,7 +209,7 @@ def create_component_from_string(self, component_string: str) -> Component:
         component = self.import_and_instantiate_component(component_path, args)
         return component
 
-    def prep_component(self, component_string: str) -> tuple[str, tuple]:
+    def prep_component(self, component_string: str) -> tuple[str, tuple[str, ...]]:
         """Transform component description string into a tuple of component paths
         and required arguments.
 
@@ -224,14 +227,14 @@ def prep_component(self, component_string: str) -> tuple[str, tuple]:
         return path, cleaned_args
 
     @staticmethod
-    def _clean_args(args: list, path: str) -> tuple:
+    def _clean_args(args: list[str], path: str) -> tuple[str, ...]:
         """Transform component arguments into a tuple, validating that each argument
         is a string.
 
         Parameters
         ----------
         args
-            List of arguments to the component specified at ``path``.
+            Tuple of arguments to the component specified at ``path``.
         path
             Path representing the component for which arguments are being cleaned.
 
@@ -255,7 +258,9 @@ def _clean_args(args: list, path: str) -> tuple:
         return tuple(out)
 
     @staticmethod
-    def import_and_instantiate_component(component_path: str, args: tuple[str]) -> Component:
+    def import_and_instantiate_component(
+        component_path: str, args: tuple[str, ...]
+    ) -> Component:
         """Transform a tuple representing a Component into an actual instantiated
         component object.
 
@@ -271,4 +276,9 @@ def import_and_instantiate_component(component_path: str, args: tuple[str]) -> C
         -------
             An instantiated component object.
         """
-        return import_by_path(component_path)(*args)
+        component = import_by_path(component_path)(*args)
+        if not isinstance(component, Component):
+            raise ImportError(
+                f"Attempted to import f{component_path}, which is not a component."
+            )
+        return component