Fix errors when using Task and TaskWithoutPath in task modules.

docs/source/changes.md

@@ -22,6 +22,8 @@ releases are available on [PyPI](https://pypi.org/project/pytask) and
   remains the same, the consecutive tasks are not executed. It remained from when pytask
   relied on timestamps.
 - {pull}`497` removes unnecessary code in the collection of tasks.
+- {pull}`498` fixes an error when using {class}`~pytask.Task` and
+  {class}`~pytask.TaskWithoutPath` in task modules.
 
 ## 0.4.2 - 2023-11-08
 

src/_pytask/collect.py

@@ -275,7 +275,7 @@ def pytask_collect_task(
             produces=products,
             markers=markers,
         )
-    if isinstance(obj, PTask):
+    if isinstance(obj, PTask) and not inspect.isclass(obj):
         return obj
     return None
 

src/_pytask/mark_utils.py

@@ -5,6 +5,7 @@
 """
 from __future__ import annotations
 
+import inspect
 from typing import Any
 from typing import TYPE_CHECKING
 
@@ -18,7 +19,7 @@
 
 def get_all_marks(obj_or_task: Any | PTask) -> list[Mark]:
     """Get all marks from a callable or task."""
-    if isinstance(obj_or_task, PTask):
+    if isinstance(obj_or_task, PTask) and not inspect.isclass(obj_or_task):
         marks = obj_or_task.markers
     else:
         obj = obj_or_task

tests/test_collect.py

@@ -679,3 +679,14 @@ def task_mixed(): pass
     assert result.exit_code == ExitCode.COLLECTION_FAILED
     assert "Could not collect" in result.output
     assert "The task cannot have" in result.output
+
+
+@pytest.mark.end_to_end()
+def test_module_can_be_collected(runner, tmp_path):
+    source = """
+    from pytask import Task, TaskWithoutPath
+    """
+    tmp_path.joinpath("task_example.py").write_text(textwrap.dedent(source))
+
+    result = runner.invoke(cli, [tmp_path.as_posix()])
+    assert result.exit_code == ExitCode.OK

tests/test_execute.py

@@ -1008,3 +1008,43 @@ def func(path):
     session = build(tasks=[task])
     assert session.exit_code == ExitCode.OK
     assert tmp_path.joinpath("out.txt").exists()
+
+
+def test_collect_task(runner, tmp_path):
+    source = """
+    from pytask import Task, PathNode
+    from pathlib import Path
+
+    def func(path): path.touch()
+
+    task_create_file = Task(
+        base_name="task",
+        function=func,
+        path=Path(__file__),
+        produces={"path": PathNode(path=Path(__file__).parent / "out.txt")},
+    )
+    """
+    tmp_path.joinpath("task_example.py").write_text(textwrap.dedent(source))
+    result = runner.invoke(cli, [tmp_path.as_posix()])
+    assert result.exit_code == ExitCode.OK
+    assert tmp_path.joinpath("out.txt").exists()
+
+
+def test_collect_task_without_path(runner, tmp_path):
+    source = """
+    from pytask import TaskWithoutPath, PathNode
+    from pathlib import Path
+
+    def func(path): path.touch()
+
+    task_create_file = TaskWithoutPath(
+        name="task",
+        function=func,
+        produces={"path": PathNode(path=Path(__file__).parent / "out.txt")},
+    )
+    """
+    tmp_path.joinpath("task_example.py").write_text(textwrap.dedent(source))
+
+    result = runner.invoke(cli, [tmp_path.as_posix()])
+    assert result.exit_code == ExitCode.OK
+    assert tmp_path.joinpath("out.txt").exists()