Add creation of task list instance with new file

blockbuster/core/model.py

@@ -122,6 +122,7 @@ class TaskList:
     @classmethod
     def from_file(cls, file):
         task = cls(file=file)
+        file.touch()
         task.read_file()
         return task
 

tests/test_tasklist.py

@@ -1,4 +1,7 @@
 # pylint: disable=protected-access, redefined-outer-name
+from hashlib import sha256
+from pathlib import Path
+
 import blockbuster.core.model as model
 from blockbuster.core import TASKS_ADDED, TASKS_DELETED, TASKS_UPDATED
 from blockbuster.core.model import Event, Task, TaskList
@@ -8,14 +11,22 @@ def test_tasks_hash(test_tasks, test_tasks_hash):
     assert model._tasks_hash(test_tasks) == test_tasks_hash
 
 
-def test_from_file(test_file, test_tasks, test_tasks_hash):
+def test_from_existing_file(test_file, test_tasks, test_tasks_hash):
     task_list = TaskList.from_file(test_file)
     assert len(task_list.tasks) == len(test_tasks)
     for task in task_list.tasks:
         assert isinstance(task, Task)
     assert task_list.tasks_hash == test_tasks_hash
 
 
+def test_from_new_file(tmp_path):
+    test_file = Path(tmp_path, "new_test_file")
+    task_list = TaskList.from_file(test_file)
+    assert test_file.exists()
+    assert task_list.tasks == []
+    assert task_list.tasks_hash == sha256("".encode("UTF-8")).hexdigest()
+
+
 def test_add_tasks(additions, test_file, test_tasks):
     task_list = TaskList.from_file(test_file)
     event = task_list.add_tasks(additions)