Support static type checking

MANIFEST.in

@@ -1,5 +1,6 @@
 include LICENSE
 include README.rst
+include pytest_snapshot/py.typed
 
 recursive-exclude * __pycache__
 recursive-exclude * *.py[co]

pytest_snapshot/_utils.py

@@ -1,6 +1,7 @@
 import os
 import re
 from pathlib import Path
+from typing import List, Tuple
 
 import pytest
 
@@ -44,7 +45,7 @@ def might_be_valid_filename(s: str) -> bool:
     )
 
 
-def simple_version_parse(version: str):
+def simple_version_parse(version: str) -> Tuple[int, int, int]:
     """
     Returns a 3 tuple of the versions major, minor, and patch.
     Raises a value error if the version string is unsupported.
@@ -75,7 +76,7 @@ def _pytest_expected_on_right() -> bool:
         return pytest_version >= (5, 4, 0)
 
 
-def flatten_dict(d: dict):
+def flatten_dict(d: dict) -> List[Tuple[List, ...]]:
     """
     Returns the flattened dict representation of the given dict.
 
@@ -96,7 +97,7 @@ def flatten_dict(d: dict):
     return result
 
 
-def _flatten_dict(obj, result, prefix):
+def _flatten_dict(obj: dict, result: list, prefix: list) -> None:
     if type(obj) is dict:
         for k, v in obj.items():
             prefix.append(k)
@@ -106,7 +107,7 @@ def _flatten_dict(obj, result, prefix):
         result.append((list(prefix), obj))
 
 
-def flatten_filesystem_dict(d):
+def flatten_filesystem_dict(d: dict) -> dict:
     """
     Returns the flattened dict of a nested dictionary structure describing a filesystem.
 

pytest_snapshot/plugin.py

@@ -2,7 +2,7 @@
 import os
 import re
 from pathlib import Path
-from typing import List, Union
+from typing import Any, Callable, List, Tuple, Union
 
 import pytest
 import _pytest.python
@@ -36,7 +36,7 @@ def snapshot(request):
         yield snapshot
 
 
-def _assert_equal(value, snapshot) -> None:
+def _assert_equal(value: Any, snapshot: Any) -> None:
     if _pytest_expected_on_right():
         assert value == snapshot
     else:
@@ -68,12 +68,12 @@ def _file_decode(data: bytes) -> str:
 
 
 class Snapshot:
-    _snapshot_update = None  # type: bool
-    _allow_snapshot_deletion = None  # type: bool
-    _created_snapshots = None  # type: List[Path]
-    _updated_snapshots = None  # type: List[Path]
-    _snapshots_to_delete = None  # type: List[Path]
-    _snapshot_dir = None  # type: Path
+    _snapshot_update: bool
+    _allow_snapshot_deletion: bool
+    _created_snapshots: List[Path]
+    _updated_snapshots: List[Path]
+    _snapshots_to_delete: List[Path]
+    _snapshot_dir: Path
 
     def __init__(self, snapshot_update: bool, allow_snapshot_deletion: bool, snapshot_dir: Path):
         self._snapshot_update = snapshot_update
@@ -135,7 +135,9 @@ def _snapshot_path(self, snapshot_name: Union[str, Path]) -> Path:
 
         return snapshot_path
 
-    def _get_compare_encode_decode(self, value: Union[str, bytes]):
+    def _get_compare_encode_decode(self, value: Union[str, bytes]) -> Tuple[
+        Callable[[Any, Any], None], Callable[..., bytes], Callable[..., str]
+    ]:
         """
         Returns a 3-tuple of a compare function, an encoding function, and a decoding function.
 
@@ -151,7 +153,7 @@ def _get_compare_encode_decode(self, value: Union[str, bytes]):
         else:
             raise TypeError('value must be str or bytes')
 
-    def assert_match(self, value: Union[str, bytes], snapshot_name: Union[str, Path]):
+    def assert_match(self, value: Union[str, bytes], snapshot_name: Union[str, Path]) -> None:
         """
         Asserts that ``value`` equals the current value of the snapshot with the given ``snapshot_name``.
 
@@ -202,7 +204,7 @@ def assert_match(self, value: Union[str, bytes], snapshot_name: Union[str, Path]
                     "snapshot {} doesn't exist. (run pytest with --snapshot-update to create it)".format(
                         shorten_path(snapshot_path)))
 
-    def assert_match_dir(self, dir_dict: dict, snapshot_dir_name: Union[str, Path]):
+    def assert_match_dir(self, dir_dict: dict, snapshot_dir_name: Union[str, Path]) -> None:
         """
         Asserts that the values in dir_dict equal the current values in the given snapshot directory.
 

setup.cfg

@@ -28,6 +28,8 @@ classifiers =
 
 [options]
 packages = pytest_snapshot
+zip_safe = False
+include_package_data = True
 python_requires = >=3.5
 install_requires =
     pytest >= 3.0.0