Fix all type hints, add missing type hints (#33)

* add mypy.ini and launch.json
* cleanup the modify_items hook registration
* stub the OrderedDict type which is not available as type hint in Python 3.6

Author: DevilXD

.vscode/launch.json

@@ -0,0 +1,15 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Test plugin",
+            "type": "python",
+            "request": "launch",
+            "module": "pytest",
+            "args": ["-v"]
+        }
+    ]
+}

AUTHORS

@@ -5,3 +5,4 @@ Adam Talsma <[email protected]>
 Brian Maissy <[email protected]>
 Jonas Zinn <[email protected]>
 Andrew Gilbert <[email protected]>
+Bartosz Peszek <[email protected]>

docs/source/conf.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
-#
+from typing import List, Dict
+
 # pytest-order documentation build configuration file, created by
 # sphinx-quickstart on Mon Mar 17 18:20:44 2014.
 #
@@ -75,7 +76,7 @@
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
-exclude_patterns = []
+exclude_patterns: List[str] = []
 
 # The reST default role (used for this markup: `text`) to use for all
 # documents.
@@ -135,7 +136,7 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = []
+html_static_path: List[str] = []
 
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied
@@ -188,7 +189,7 @@
 
 # -- Options for LaTeX output ---------------------------------------------
 
-latex_elements = {
+latex_elements: Dict[str, str] = {
     # The paper size ("letterpaper" or "a4paper").
     # "papersize": "letterpaper",
 

mypy.ini

@@ -0,0 +1,19 @@
+[mypy]
+; Ensures correct typing information inside non-typed functions
+check_untyped_defs = True
+; Strict checking for None
+no_implicit_optional = True
+; Disallow none and partial generics
+disallow_any_generics = True
+; Point out pointless things
+warn_redundant_casts = True
+warn_unused_ignores = True
+; Misc
+show_error_codes = True
+
+; These are needed for VSCode
+; Silences errors about missing imports
+; (type-checks correctly when they're not missing tho)
+ignore_missing_imports = True
+; Needed to position the underline correctly
+show_column_numbers = True

pytest_order/item.py

@@ -1,11 +1,14 @@
 import sys
-from typing import List, Optional, Union, Dict, Tuple
+from typing import Optional, List, Dict, Tuple, Generic, TypeVar
 
 from _pytest.python import Function
 
 from .settings import Scope, Settings
 
 
+_ItemType = TypeVar("_ItemType", "Item", "ItemGroup")
+
+
 class Item:
     """Represents a single test item."""
 
@@ -46,8 +49,8 @@ def __init__(
         items: List[Item],
         settings: Settings,
         scope: Scope,
-        rel_marks: List["RelativeMark"],
-        dep_marks: List["RelativeMark"],
+        rel_marks: List["RelativeMark[Item]"],
+        dep_marks: List["RelativeMark[Item]"],
     ) -> None:
         self.items = items
         self.settings = settings
@@ -63,16 +66,16 @@ def __init__(
         self.dep_marks = filter_marks(dep_marks, items)
 
     def collect_markers(self, item: Item) -> None:
-        if item.order is not None:
-            self.handle_order_mark(item)
+        self.handle_order_mark(item)
         if item.nr_rel_items or item.order is None:
             self.unordered_items.append(item)
 
     def handle_order_mark(self, item: Item) -> None:
-        if item.order < 0:
-            self._end_items.setdefault(item.order, []).append(item)
-        else:
-            self._start_items.setdefault(item.order, []).append(item)
+        if item.order is not None:
+            if item.order < 0:
+                self._end_items.setdefault(item.order, []).append(item)
+            else:
+                self._start_items.setdefault(item.order, []).append(item)
 
     def sort_numbered_items(self) -> List[Item]:
         self.start_items = sorted(self._start_items.items())
@@ -114,22 +117,26 @@ def print_unhandled_items(self) -> None:
     def number_of_rel_groups(self) -> int:
         return len(self.rel_marks) + len(self.dep_marks)
 
-    def handle_rel_marks(self, sorted_list: List[Item]) -> None:
+    def handle_rel_marks(
+        self, sorted_list: List[Item]
+    ) -> None:
         self.handle_relative_marks(
             self.rel_marks, sorted_list, self.all_rel_marks
         )
 
-    def handle_dep_marks(self, sorted_list: List[Item]) -> None:
+    def handle_dep_marks(
+        self, sorted_list: List[Item]
+    ) -> None:
         self.handle_relative_marks(
             self.dep_marks, sorted_list, self.all_dep_marks
         )
 
     @staticmethod
     def handle_relative_marks(
-        marks: List["RelativeMark"],
+        marks: List["RelativeMark[Item]"],
         sorted_list: List[Item],
-        all_marks: List["RelativeMark"],
-    ):
+        all_marks: List["RelativeMark[Item]"],
+    ) -> None:
         for mark in reversed(marks):
             if move_item(mark, sorted_list):
                 marks.remove(mark)
@@ -138,19 +145,21 @@ def handle_relative_marks(
     def group_order(self) -> Optional[int]:
         if self.start_items:
             return self.start_items[0][0]
-        if self.end_items:
+        elif self.end_items:
             return self.end_items[-1][0]
+        return None
 
 
 class ItemGroup:
-    """Holds a group of sorted items with the same group order scope.
+    """
+    Holds a group of sorted items with the same group order scope.
     Used for sorting groups similar to Item for sorting items.
     """
 
     def __init__(
         self, items: Optional[List[Item]] = None, order: Optional[int] = None
     ) -> None:
-        self.items = items or []
+        self.items: List[Item] = items or []
         self.order = order
         self.nr_rel_items = 0
 
@@ -168,25 +177,26 @@ def extend(self, groups: List["ItemGroup"], order: Optional[int]) -> None:
         self.order = order
 
 
-class RelativeMark:
-    """Represents a marker for an item or an item group.
+class RelativeMark(Generic[_ItemType]):
+    """
+    Represents a marker for an item or an item group.
     Holds two related items or groups and their relationship.
     """
 
     def __init__(
         self,
-        item: Union[Item, ItemGroup],
-        item_to_move: Union[Item, ItemGroup],
+        item: _ItemType,
+        item_to_move: _ItemType,
         move_after: bool,
     ) -> None:
-        self.item: Item = item
-        self.item_to_move: Item = item_to_move
+        self.item: _ItemType = item
+        self.item_to_move: _ItemType = item_to_move
         self.move_after: bool = move_after
 
 
 def filter_marks(
-    marks: List[RelativeMark], all_items: List[Item]
-) -> List[RelativeMark]:
+    marks: List[RelativeMark[_ItemType]], all_items: List[Item]
+) -> List[RelativeMark[_ItemType]]:
     result = []
     for mark in marks:
         if mark.item in all_items and mark.item_to_move in all_items:
@@ -197,7 +207,7 @@ def filter_marks(
 
 
 def move_item(
-    mark: RelativeMark, sorted_items: List[Union[Item, ItemGroup]]
+    mark: RelativeMark[_ItemType], sorted_items: List[_ItemType]
 ) -> bool:
     if (
         mark.item not in sorted_items

pytest_order/plugin.py

@@ -26,23 +26,17 @@ def pytest_configure(config: Config) -> None:
         "in relation to one another. " + provided_by_pytest_order
     )
     config.addinivalue_line("markers", config_line)
-
+    # We need to dynamically add this `tryfirst` decorator to the plugin:
+    # only when the CLI option is present should the decorator be added.
+    # Thus, we manually run the decorator on the class function and
+    # manually replace it.
     if config.getoption("indulgent_ordering"):
-        # We need to dynamically add this `tryfirst` decorator to the plugin:
-        # only when the CLI option is present should the decorator be added.
-        # Thus, we manually run the decorator on the class function and
-        # manually replace it.
-        # Python 2.7 didn't allow arbitrary attributes on methods, so we have
-        # to keep the function as a function and then add it to the class as a
-        # pseudo method.  Since the class is purely for structuring and `self`
-        # is never referenced, this seems reasonable.
-        OrderingPlugin.pytest_collection_modifyitems = pytest.hookimpl(
-            function=modify_items, tryfirst=True
-        )
+        wrapper = pytest.hookimpl(tryfirst=True)
     else:
-        OrderingPlugin.pytest_collection_modifyitems = pytest.hookimpl(
-            function=modify_items, trylast=True
-        )
+        wrapper = pytest.hookimpl(trylast=True)
+    setattr(
+        OrderingPlugin, "pytest_collection_modifyitems", wrapper(modify_items)
+    )
     config.pluginmanager.register(OrderingPlugin(), "orderingplugin")
 
 
@@ -112,7 +106,7 @@ def pytest_addoption(parser: Parser) -> None:
 
 class OrderingPlugin:
     """
-    Plugin implementation
+    Plugin implementation.
 
     By putting this in a class, we are able to dynamically register it after
     the CLI is parsed.