Enable strict mode for mypy + other error codes (#149)

* chore(mypy): enable strict mode and more error codes
* chore: comply with `mypy` new rules
* chore: ignore some type errors related to `importlib_metadata`

deptry/cli.py

@@ -1,6 +1,6 @@
 import logging
-import pathlib
 import sys
+from pathlib import Path
 from typing import List, Optional, Tuple, Union
 
 import click
@@ -37,7 +37,7 @@ def configure_logger(ctx: click.Context, _param: click.Parameter, value: bool) -
 
 
 @click.command()
-@click.argument("root", type=click.Path(exists=True), required=False)
+@click.argument("root", type=click.Path(exists=True, path_type=Path), required=False)
 @click.option(
     "--verbose",
     "-v",
@@ -178,7 +178,7 @@ def configure_logger(ctx: click.Context, _param: click.Parameter, value: bool) -
     hidden=True,
 )
 def deptry(
-    root: pathlib.Path,
+    root: Optional[Path],
     verbose: bool,
     ignore_obsolete: Tuple[str, ...],
     ignore_missing: Tuple[str, ...],
@@ -232,4 +232,4 @@ def deptry(
 
 
 def display_deptry_version() -> None:
-    logging.info(f'deptry {metadata.version("deptry")}')
+    logging.info(f'deptry {metadata.version("deptry")}')  # type: ignore[no-untyped-call]

deptry/compat.py

@@ -6,3 +6,5 @@
 else:
     import importlib_metadata as metadata  # noqa: F401
     from importlib_metadata import PackageNotFoundError  # noqa: F401
+
+__all__ = ("metadata", "PackageNotFoundError")

deptry/dependency.py

@@ -44,7 +44,7 @@ def __str__(self) -> str:
 
     def find_metadata(self, name: str) -> bool:
         try:
-            metadata.distribution(name)
+            metadata.distribution(name)  # type: ignore[no-untyped-call]
             return True
         except PackageNotFoundError:
             logging.warning(
@@ -80,7 +80,7 @@ def _get_top_level_module_names_from_top_level_txt(self) -> List[str]:
 
         This function extracts these names, if a top-level.txt file exists.
         """
-        metadata_top_levels = metadata.distribution(self.name).read_text("top_level.txt")
+        metadata_top_levels = metadata.distribution(self.name).read_text("top_level.txt")  # type: ignore[no-untyped-call]
         if metadata_top_levels:
             return [x for x in metadata_top_levels.split("\n") if len(x) > 0]
         else:
@@ -101,7 +101,7 @@ def _get_top_level_module_names_from_record_file(self) -> List[str]:
         """
         top_levels = []
         try:
-            metadata_records = metadata.distribution(self.name).read_text("RECORD")
+            metadata_records = metadata.distribution(self.name).read_text("RECORD")  # type: ignore[no-untyped-call]
 
             if not metadata_records:
                 return []

deptry/dependency_getter/pyproject_toml.py

@@ -36,7 +36,7 @@ def get(self) -> List[Dependency]:
 
     def _get_pyproject_toml_dependencies(self) -> Dict[str, Any]:
         pyproject_data = load_pyproject_toml()
-        dependencies = pyproject_data["tool"]["poetry"]["dependencies"]
+        dependencies: Dict[str, Any] = pyproject_data["tool"]["poetry"]["dependencies"]
         return dependencies
 
     def _get_pyproject_toml_dev_dependencies(self) -> Dict[str, Any]:
@@ -66,14 +66,14 @@ def _log_dependencies(self, dependencies: List[Dependency]) -> None:
         logging.debug("")
 
     @staticmethod
-    def _is_optional(dep: str, spec: Union[str, dict]) -> bool:
+    def _is_optional(dep: str, spec: Union[str, Dict[str, Any]]) -> bool:
         # if of the shape `isodate = {version = "*", optional = true}` mark as optional`
         if isinstance(spec, dict) and "optional" in spec and spec["optional"]:
             return True
         return False
 
     @staticmethod
-    def _is_conditional(dep: str, spec: Union[str, dict]) -> bool:
+    def _is_conditional(dep: str, spec: Union[str, Dict[str, Any]]) -> bool:
         # if of the shape `tomli = { version = "^2.0.1", python = "<3.11" }`, mark as conditional.
         if isinstance(spec, dict) and "python" in spec and "version" in spec:
             return True

deptry/dependency_getter/requirements_txt.py

@@ -2,7 +2,7 @@
 import logging
 import os
 import re
-from typing import List, Optional, Tuple
+from typing import List, Match, Optional, Tuple
 
 from deptry.dependency import Dependency
 
@@ -117,7 +117,7 @@ def _log_dependencies(self, dependencies: List[Dependency]) -> None:
         logging.debug("")
 
     @staticmethod
-    def _line_is_url(line: str) -> Optional[re.Match]:
+    def _line_is_url(line: str) -> Optional[Match[str]]:
         return re.search("^(http|https|git\+https)", line)
 
     @staticmethod

deptry/import_parser.py

@@ -49,7 +49,7 @@ def get_imported_modules_from_str(self, file_str: str) -> List[str]:
     def _get_imported_modules_from_py(self, path_to_py_file: Path) -> List[str]:
         try:
             with open(path_to_py_file) as f:
-                root = ast.parse(f.read(), path_to_py_file)  # type: ignore
+                root = ast.parse(f.read(), path_to_py_file)  # type: ignore[call-overload]
             import_nodes = self._get_import_nodes_from(root)
             return self._get_import_modules_from(import_nodes)
         except UnicodeDecodeError:
@@ -58,7 +58,7 @@ def _get_imported_modules_from_py(self, path_to_py_file: Path) -> List[str]:
     def _get_imported_modules_from_py_and_guess_encoding(self, path_to_py_file: Path) -> List[str]:
         try:
             with open(path_to_py_file, encoding=self._get_file_encoding(path_to_py_file)) as f:
-                root = ast.parse(f.read(), path_to_py_file)  # type: ignore
+                root = ast.parse(f.read(), path_to_py_file)  # type: ignore[call-overload]
             import_nodes = self._get_import_nodes_from(root)
             return self._get_import_modules_from(import_nodes)
         except UnicodeDecodeError:
@@ -95,12 +95,12 @@ def _get_import_modules_from(nodes: List[Union[ast.Import, ast.ImportFrom]]) ->
             if isinstance(node, ast.Import):
                 modules += [x.name.split(".")[0] for x in node.names]
             # nodes for imports like `from . import foo` do not have a module attribute.
-            elif isinstance(node, ast.ImportFrom) and node.module and node.level == 0:
+            elif node.module and node.level == 0:
                 modules.append(node.module.split(".")[0])
         return modules
 
     @staticmethod
-    def _flatten_list(modules_per_file: List[List]) -> List:
+    def _flatten_list(modules_per_file: List[List[str]]) -> List[str]:
         all_modules = []
         for modules in modules_per_file:
             if modules:

deptry/issue_finders/transitive.py

@@ -1,5 +1,5 @@
 import logging
-from typing import List, Optional, Tuple
+from typing import List, Tuple, cast
 
 from deptry.dependency import Dependency
 from deptry.module import Module
@@ -24,13 +24,15 @@ def __init__(
         self.dependencies = dependencies
         self.ignore_transitive = ignore_transitive
 
-    def find(self) -> List[Optional[str]]:
+    def find(self) -> List[str]:
         logging.debug("\nScanning for transitive dependencies...")
         transitive_dependencies = []
         for module in self.imported_modules:
             logging.debug(f"Scanning module {module.name}...")
             if self._is_transitive(module):
-                transitive_dependencies.append(module.package)
+                # `self._is_transitive` only returns `True` if the package is not None.
+                module_package = cast(str, module.package)
+                transitive_dependencies.append(module_package)
         return transitive_dependencies
 
     def _is_transitive(self, module: Module) -> bool:

deptry/json_writer.py

@@ -1,5 +1,5 @@
 import json
-from typing import Dict
+from typing import Dict, List
 
 
 class JsonWriter:
@@ -13,6 +13,6 @@ class JsonWriter:
     def __init__(self, json_output: str) -> None:
         self.json_output = json_output
 
-    def write(self, issues: Dict) -> None:
+    def write(self, issues: Dict[str, List[str]]) -> None:
         with open(self.json_output, "w", encoding="utf-8") as f:
             json.dump(issues, f, ensure_ascii=False, indent=4)

deptry/module.py

@@ -95,7 +95,8 @@ def _get_package_name_from_metadata(self) -> Optional[str]:
         Most packages simply have a field called "Name" in their metadata. This method extracts that field.
         """
         try:
-            return metadata.metadata(self.name)["Name"]
+            name: str = metadata.metadata(self.name)["Name"]  # type: ignore[no-untyped-call]
+            return name
         except PackageNotFoundError:
             return None
 

deptry/notebook_import_extractor.py

@@ -1,7 +1,7 @@
 import json
 import re
 from pathlib import Path
-from typing import List
+from typing import Any, Dict, List
 
 
 class NotebookImportExtractor:
@@ -26,22 +26,22 @@ def extract(self, path_to_ipynb: Path) -> List[str]:
         return self._flatten(import_statements)
 
     @staticmethod
-    def _read_ipynb_file(path_to_ipynb: Path) -> dict:
+    def _read_ipynb_file(path_to_ipynb: Path) -> Dict[str, Any]:
         with open(path_to_ipynb, "r") as f:
-            notebook = json.load(f)
+            notebook: Dict[str, Any] = json.load(f)
         return notebook
 
     @staticmethod
-    def _keep_code_cells(notebook: dict) -> List[dict]:
+    def _keep_code_cells(notebook: Dict[str, Any]) -> List[Dict[str, Any]]:
         return [cell for cell in notebook["cells"] if cell["cell_type"] == "code"]
 
     @staticmethod
     def _contains_import_statements(line: str) -> bool:
         return re.search(r"^(?:from\s+(\w+)(?:\.\w+)?\s+)?import\s+([^\s,.]+)(?:\.\w+)?", line) is not None
 
-    def _extract_import_statements_from_cell(self, cell: dict) -> List[str]:
+    def _extract_import_statements_from_cell(self, cell: Dict[str, Any]) -> List[str]:
         return [line for line in cell["source"] if self._contains_import_statements(line)]
 
     @staticmethod
-    def _flatten(list_of_lists: List[List]) -> List:
+    def _flatten(list_of_lists: List[List[str]]) -> List[str]:
         return [item for sublist in list_of_lists for item in sublist]

deptry/utils.py

@@ -2,7 +2,7 @@
 import sys
 from contextlib import contextmanager
 from pathlib import Path
-from typing import Dict, Generator
+from typing import Any, Dict, Generator
 
 if sys.version_info >= (3, 11):
     import tomllib
@@ -33,7 +33,7 @@ def run_within_dir(path: Path) -> Generator[None, None, None]:
         os.chdir(oldpwd)
 
 
-def load_pyproject_toml(pyproject_toml_path: str = PYPROJECT_TOML_PATH) -> Dict:
+def load_pyproject_toml(pyproject_toml_path: str = PYPROJECT_TOML_PATH) -> Dict[str, Any]:
     try:
         with Path(pyproject_toml_path).open("rb") as pyproject_file:
             return tomllib.load(pyproject_file)

pyproject.toml

@@ -48,14 +48,26 @@ profile = "black"
 
 [tool.mypy]
 files = ["deptry", "scripts"]
-disallow_untyped_defs = true
 disallow_any_unimported = true
-no_implicit_optional = true
-check_untyped_defs = true
-warn_return_any = false
-warn_unused_ignores = true
+enable_error_code = [
+    "ignore-without-code",
+    "redundant-expr",
+    "truthy-bool",
+]
+strict = true
+warn_unreachable = true
+pretty = true
 show_error_codes = true
-ignore_missing_imports = true
+
+# Ignore warnings for unused ignores because of https://github.com/python/mypy/issues/8823.
+# In some Python versions, we can end up with backport modules being untyped, while they are typed on others.
+[[tool.mypy.overrides]]
+module = [
+    "deptry.cli",
+    "deptry.dependency",
+    "deptry.module",
+]
+warn_unused_ignores = false
 
 [tool.deptry]
 exclude = [