Change type of custom mapping files to a Optional[Set[Path]]

Works for a single input

fawltydeps/cli_parser.py

@@ -166,6 +166,8 @@ def populate_parser_paths_options(parser: argparse._ActionsContainer) -> None:
     )
     parser.add_argument(
         "--custom-mapping-file",
+        nargs="+",
+        action="union",
         type=Path,
         metavar="FILE_PATH",
         help=(

fawltydeps/packages.py

@@ -116,14 +116,16 @@ class UserDefinedMapping(BasePackageResolver):
 
     def __init__(
         self,
-        mapping_path: Optional[Path] = None,
+        mapping_paths: Optional[Set[Path]] = None,
         custom_mapping: Optional[CustomMapping] = None,
     ) -> None:
-        self.mapping_path = mapping_path
-        if self.mapping_path and not self.mapping_path.is_file():
-            raise UnparseablePathException(
-                ctx="Given mapping path is not a file.", path=self.mapping_path
-            )
+        self.mapping_paths = mapping_paths
+        if self.mapping_paths:
+            for path in self.mapping_paths:
+                if not path.is_file():
+                    raise UnparseablePathException(
+                        ctx="Given mapping path is not a file.", path=path
+                    )
         self.custom_mapping = custom_mapping
         # We enumerate packages declared in the mapping _once_ and cache the result here:
         self._packages: Optional[Dict[str, Package]] = None
@@ -134,18 +136,19 @@ def packages(self) -> Dict[str, Package]:
         """Gather a custom mapping given by a user.
 
         Mapping may come from two sources:
-        * _mapping_path_ which is a file in a given path, which is parsed to a ditionary
+        * _mapping_paths_ which is a set of files in a given path, which is parsed to a ditionary
         * _custom_mapping_ which is a dictionary of package to imports mapping.
 
         This enumerates the available packages  _once_, and caches the result for
         the remainder of this object's life in _packages.
         """
         custom_mapping_from_file: Dict[str, List[str]] = {}
 
-        if self.mapping_path is not None:
-            logger.debug(f"Loading user-defined mapping from {self.mapping_path}")
-            with open(self.mapping_path, "rb") as mapping_file:
-                custom_mapping_from_file = tomllib.load(mapping_file)
+        if self.mapping_paths is not None:
+            logger.debug(f"Loading user-defined mapping from {self.mapping_paths}")
+            for path in self.mapping_paths:
+                with open(path, "rb") as mapping_file:
+                    custom_mapping_from_file = tomllib.load(mapping_file)
 
         mapping = {
             Package.normalize_name(name): Package(
@@ -166,7 +169,7 @@ def packages(self) -> Dict[str, Package]:
                         "from the configuration file are appended to ones "
                         "found in the mapping file.",
                         normalised_name,
-                        self.mapping_path,
+                        self.mapping_paths,
                     )
                     mapping[normalised_name].add_import_names(
                         *imports, mapping=DependenciesMapping.USER_DEFINED
@@ -354,7 +357,7 @@ def lookup_packages(self, package_names: Set[str]) -> Dict[str, Package]:
 
 def resolve_dependencies(
     dep_names: Iterable[str],
-    custom_mapping_file: Optional[Path] = None,
+    custom_mapping_file: Optional[Set[Path]] = None,
     custom_mapping: Optional[CustomMapping] = None,
     pyenv_path: Optional[Path] = None,
     install_deps: bool = False,
@@ -378,7 +381,7 @@ def resolve_dependencies(
     if custom_mapping_file or custom_mapping:
         resolvers.append(
             UserDefinedMapping(
-                mapping_path=custom_mapping_file, custom_mapping=custom_mapping
+                mapping_paths=custom_mapping_file, custom_mapping=custom_mapping
             )
         )
 

fawltydeps/settings.py

@@ -110,7 +110,7 @@ class Settings(BaseSettings):  # type: ignore
     code: Set[PathOrSpecial] = {Path(".")}
     deps: Set[Path] = {Path(".")}
     pyenv: Optional[Path] = None
-    custom_mapping_file: Optional[Path] = None
+    custom_mapping_file: Optional[Set[Path]] = None
     custom_mapping: Optional[CustomMapping] = None
     ignore_undeclared: Set[str] = set()
     ignore_unused: Set[str] = set()

tests/test_packages.py

@@ -159,14 +159,14 @@ def test_user_defined_mapping__well_formated_input_file__parses_correctly(
         )
     )
 
-    udm = UserDefinedMapping(custom_mapping_file)
+    udm = UserDefinedMapping({custom_mapping_file})
     mapped_packages = udm.packages
     assert set(mapped_packages.keys()) == {"apache_airflow", "attrs"}
 
 
 def test_user_defined_mapping__input_is_no_file__raises_unparsable_path_exeption():
     with pytest.raises(UnparseablePathException):
-        UserDefinedMapping(SAMPLE_PROJECTS_DIR)
+        UserDefinedMapping({SAMPLE_PROJECTS_DIR})
 
 
 def test_user_defined_mapping__no_input__returns_empty_mapping():
@@ -327,18 +327,19 @@ def test_LocalPackageResolver_lookup_packages(dep_name, expect_import_names):
 def test_resolve_dependencies__focus_on_mappings(
     dep_names, user_mapping, expected, tmp_path
 ):
-    custom_mapping_file = None
+    custom_mapping_files = None
     custom_mapping = None
     if user_mapping is not None:
         custom_mapping = user_mapping.get("configuration")
         if "file" in user_mapping:
             custom_mapping_file = tmp_path / "mapping.toml"
             custom_mapping_file.write_text(dedent(user_mapping["file"]))
+            custom_mapping_files = {custom_mapping_file}
 
     assert (
         resolve_dependencies(
             dep_names,
-            custom_mapping_file=custom_mapping_file,
+            custom_mapping_file=custom_mapping_files,
             custom_mapping=custom_mapping,
         )
         == expected

tests/test_settings.py

@@ -231,12 +231,12 @@ class SettingsTestVector:
         config=dict(
             actions=["list_deps"],
             deps=["my_requirements.txt"],
-            custom_mapping_file="mapping.toml",
+            custom_mapping_file=["mapping.toml"],
         ),
         expect=make_settings_dict(
             actions={Action.LIST_DEPS},
             deps={Path("my_requirements.txt")},
-            custom_mapping_file=Path("mapping.toml"),
+            custom_mapping_file={Path("mapping.toml")},
         ),
     ),
     SettingsTestVector(
@@ -259,20 +259,20 @@ class SettingsTestVector:
             deps=["my_requirements.txt"],
             custom_mapping={"package": ["foo", "bar"]},
         ),
-        cmdline=dict(custom_mapping_file="mapping.toml"),
+        cmdline=dict(custom_mapping_file=["mapping.toml"]),
         expect=make_settings_dict(
             actions={Action.LIST_DEPS},
             deps={Path("my_requirements.txt")},
             custom_mapping={"package": ["foo", "bar"]},
-            custom_mapping_file=Path("mapping.toml"),
+            custom_mapping_file={Path("mapping.toml")},
         ),
     ),
     SettingsTestVector(
         "config_file_with_mapping_and_cli__cli_mapping_overrides_config",
-        config=dict(custom_mapping_file="foo.toml"),
-        cmdline=dict(custom_mapping_file="mapping.toml"),
+        config=dict(custom_mapping_file=["foo.toml"]),
+        cmdline=dict(custom_mapping_file=["mapping.toml"]),
         expect=make_settings_dict(
-            custom_mapping_file=Path("mapping.toml"),
+            custom_mapping_file={Path("mapping.toml")},
         ),
     ),
     SettingsTestVector(