Move mapping of a single dependency to imports

to scope of the module,

as discussed with @vreuter

Author: mknorps

fawltydeps/check.py

@@ -55,27 +55,31 @@ def lookup_package(self, package: str) -> Optional[Tuple[str, ...]]:
         return tuple(ret) or None
 
 
-def dependencies_to_imports_mapping(
+def dependency_to_imports_mapping(
+    dependency: DeclaredDependency, local_package_lookup: LocalPackageLookup
+) -> DeclaredDependency:
+    """Map imports names exposed by a dependency."""
+    import_names = local_package_lookup.lookup_package(dependency.name)
+    return (
+        dependency.replace_mapping(
+            import_names, DependenciesMapping.DEPENDENCY_TO_IMPORT
+        )
+        if import_names
+        # Fallback to IDENTITY mapping
+        else dependency
+    )
+
+
+def map_dependencies_to_imports(
     dependencies: List[DeclaredDependency],
 ) -> List[DeclaredDependency]:
     """Map dependencies names to list of imports names exposed by a package"""
 
     local_package_lookup = LocalPackageLookup()
 
-    def _dependency_to_imports_mapping(
-        dependency: DeclaredDependency,
-    ) -> DeclaredDependency:
-        import_names = local_package_lookup.lookup_package(dependency.name)
-        return (
-            dependency.replace_mapping(
-                import_names, DependenciesMapping.DEPENDENCY_TO_IMPORT
-            )
-            if import_names
-            # Fallback to IDENTITY mapping
-            else dependency
-        )
-
-    return [_dependency_to_imports_mapping(d) for d in dependencies]
+    return [
+        dependency_to_imports_mapping(d, local_package_lookup) for d in dependencies
+    ]
 
 
 def compare_imports_to_dependencies(
@@ -93,7 +97,7 @@ def compare_imports_to_dependencies(
     """
 
     # TODO consider empty list of dependency to import
-    mapped_dependencies = dependencies_to_imports_mapping(dependencies)
+    mapped_dependencies = map_dependencies_to_imports(dependencies)
 
     names_from_imports = {i.name for i in imports}
     names_from_dependencies = {

tests/test_map_dep_name_to_import_names.py

@@ -5,7 +5,7 @@
 
 import pytest
 
-from fawltydeps.check import LocalPackageLookup, dependencies_to_imports_mapping
+from fawltydeps.check import LocalPackageLookup, map_dependencies_to_imports
 from fawltydeps.types import DeclaredDependency, DependenciesMapping, Location
 
 from .utils import deps_factory
@@ -99,8 +99,8 @@ def test_LocalPackageLookup_lookup_package(dep_name, expect_import_names):
         ),
     ],
 )
-def test_dependencies_to_imports_mapping(dep_names, expected_declared_dependencies):
+def test_map_dependencies_to_imports(dep_names, expected_declared_dependencies):
     collected_dependencies = deps_factory(*dep_names)
-    mapped_dependencies = dependencies_to_imports_mapping(collected_dependencies)
+    mapped_dependencies = map_dependencies_to_imports(collected_dependencies)
 
     assert mapped_dependencies == expected_declared_dependencies