typing

RenderingTask is abstract. mypy doesn't allow assigning it to Type
variable.

See also #4645

apps/core/task/coretask.py

@@ -280,9 +280,8 @@ def get_tasks_left(self):
         return (self.get_total_tasks() - self.last_task) \
             + self.num_failed_subtasks
 
-    # pylint:disable=unused-argument
-    @classmethod
-    def get_subtasks(cls, part):
+    # pylint:disable=unused-argument,no-self-use
+    def get_subtasks(self, part) -> Dict[str, dict]:
         return dict()
 
     def restart(self):
@@ -518,7 +517,7 @@ def copy_subtask_results(
 
 
 class CoreTaskBuilder(TaskBuilder):
-    TASK_CLASS = CoreTask
+    TASK_CLASS: Type[CoreTask]
     OUTPUT_DIR_TIME_FORMAT = '_%Y-%m-%d_%H-%M-%S'
 
     def __init__(self,

apps/rendering/task/framerenderingtask.py

@@ -1,8 +1,14 @@
 import logging
 import math
 import os
-import typing
-from typing import Callable, List, TYPE_CHECKING
+from typing import (
+    Callable,
+    Dict,
+    List,
+    TYPE_CHECKING,
+    Type,
+    cast,
+)
 from bisect import insort
 from collections import OrderedDict, defaultdict
 
@@ -174,7 +180,7 @@ def get_output_states(self):
             return result
         return []
 
-    def get_subtasks(self, part) -> typing.Dict[str, dict]:
+    def get_subtasks(self, part) -> Dict[str, dict]:
         if self.task_definition.options.use_frames:
             subtask_ids = self.frames_subtasks.get(to_unicode(part), [])
             subtask_ids = filter(None, subtask_ids)
@@ -481,7 +487,7 @@ def get_frame_name(output_name, ext, frame_num):
 
 
 class FrameRenderingTaskBuilder(RenderingTaskBuilder):
-    TASK_CLASS = FrameRenderingTask
+    TASK_CLASS: Type[FrameRenderingTask]
 
     def __init__(self, owner, task_definition, dir_manager):
         frames = task_definition.options.frames
@@ -504,7 +510,8 @@ def build_dictionary(cls, definition):
     @classmethod
     def build_minimal_definition(cls, task_type, dictionary) \
             -> 'RenderingTaskDefinition':
-        parent = super(FrameRenderingTaskBuilder, cls)
+        parent = cast(Type[RenderingTaskBuilder],
+                      super(FrameRenderingTaskBuilder, cls))
         options = dictionary.get('options') or dict()
 
         frames_string = to_unicode(options.get('frames', 1))
@@ -522,15 +529,16 @@ def build_minimal_definition(cls, task_type, dictionary) \
     @classmethod
     def build_full_definition(cls, task_type, dictionary) \
             -> 'RenderingTaskDefinition':
-        definition = super().build_full_definition(task_type, dictionary)
+        parent = cast(Type[RenderingTaskBuilder],
+                      super(FrameRenderingTaskBuilder, cls))
 
+        definition = parent.build_full_definition(task_type, dictionary)
         definition.subtasks_count = _calculate_subtasks_count(
             subtasks_count=int(dictionary['subtasks_count']),
             use_frames=definition.options.use_frames,
             frames=definition.options.frames,
             resolution=definition.resolution,
         )
-
         return definition
 
     @staticmethod

apps/rendering/task/renderingtask.py

@@ -1,7 +1,7 @@
 import logging
 import math
 import os
-from typing import Type, TYPE_CHECKING
+from typing import cast, Type, TYPE_CHECKING
 
 from pathlib import Path
 
@@ -246,7 +246,7 @@ class RenderingTaskBuilderError(Exception):
 
 
 class RenderingTaskBuilder(CoreTaskBuilder):
-    TASK_CLASS = RenderingTask
+    TASK_CLASS: Type[RenderingTask]
 
     @staticmethod
     def _scene_file(type, resources):
@@ -262,7 +262,7 @@ def _scene_file(type, resources):
 
     @classmethod
     def build_dictionary(cls, definition):
-        parent = super(RenderingTaskBuilder, cls)
+        parent = cast(Type[CoreTaskBuilder], super(RenderingTaskBuilder, cls))
 
         dictionary = parent.build_dictionary(definition)
         dictionary['options']['format'] = definition.output_format
@@ -272,10 +272,12 @@ def build_dictionary(cls, definition):
     @classmethod
     def build_minimal_definition(cls, task_type, dictionary) \
             -> 'RenderingTaskDefinition':
-        parent = super(RenderingTaskBuilder, cls)
+        parent = cast(Type[CoreTaskBuilder], super(RenderingTaskBuilder, cls))
         resources = dictionary['resources']
 
-        definition = parent.build_minimal_definition(task_type, dictionary)
+        definition = cast(
+            'RenderingTaskDefinition',
+            parent.build_minimal_definition(task_type, dictionary))
 
         if 'main_scene_file' in dictionary:
             main_scene_file = dictionary['main_scene_file']
@@ -288,10 +290,12 @@ def build_minimal_definition(cls, task_type, dictionary) \
     @classmethod
     def build_full_definition(cls, task_type, dictionary) \
             -> 'RenderingTaskDefinition':
-        parent = super(RenderingTaskBuilder, cls)
+        parent = cast(Type[CoreTaskBuilder], super(RenderingTaskBuilder, cls))
         options = dictionary['options']
 
-        definition = parent.build_full_definition(task_type, dictionary)
+        definition = cast(
+            'RenderingTaskDefinition',
+            parent.build_full_definition(task_type, dictionary))
         definition.output_format = options['format'].upper()
 
         definition.resolution = \
@@ -319,7 +323,7 @@ def build_full_definition(cls, task_type, dictionary) \
 
     @classmethod
     def get_output_path(cls, dictionary, definition):
-        parent = super(RenderingTaskBuilder, cls)
+        parent = cast(Type[CoreTaskBuilder], super(RenderingTaskBuilder, cls))
         path = parent.get_output_path(dictionary, definition)
 
         return '{}.{}'.format(path, dictionary['options']['format'])

tests/apps/core/task/test_coretask.py

@@ -524,8 +524,6 @@ def _get_task_def_dict(
 
     def test_init(self):
         builder = self._get_core_task_builder()
-        assert builder.TASK_CLASS == CoreTaskBuilder.TASK_CLASS
-        assert builder.TASK_CLASS == CoreTask
         assert builder.task_definition is not None
         assert builder.owner is not None
         assert isinstance(builder.dir_manager, MagicMock)
@@ -544,12 +542,6 @@ class C(object):
         assert kwargs["owner"] is not None
         assert isinstance(kwargs["task_definition"], MagicMock)
 
-    def test_build(self):
-        builder = self._get_core_task_builder()
-        # CoreTask is now abstract
-        with self.assertRaises(TypeError):
-            builder.build()
-
     @freeze_time('2019-01-01 00:00:00')
     def test_get_output_path_returns_correct_path(self):
         builder = self._get_core_task_builder()