refactor: Extract validation and path helpers to utils module

commands/add.py

@@ -1,22 +1,8 @@
 """Add task command."""
 
 import json
-from pathlib import Path
-
-
-def get_tasks_file():
-    """Get path to tasks file."""
-    return Path.home() / ".local" / "share" / "task-cli" / "tasks.json"
-
-
-def validate_description(description):
-    """Validate task description."""
-    # NOTE: Validation logic scattered here - should be in utils (refactor bounty)
-    if not description:
-        raise ValueError("Description cannot be empty")
-    if len(description) > 200:
-        raise ValueError("Description too long (max 200 chars)")
-    return description.strip()
+from utils.paths import get_tasks_file
+from utils.validation import validate_description
 
 
 def add_task(description):

commands/done.py

@@ -1,20 +1,8 @@
 """Mark task done command."""
 
 import json
-from pathlib import Path
-
-
-def get_tasks_file():
-    """Get path to tasks file."""
-    return Path.home() / ".local" / "share" / "task-cli" / "tasks.json"
-
-
-def validate_task_id(tasks, task_id):
-    """Validate task ID exists."""
-    # NOTE: Validation logic scattered here - should be in utils (refactor bounty)
-    if task_id < 1 or task_id > len(tasks):
-        raise ValueError(f"Invalid task ID: {task_id}")
-    return task_id
+from utils.paths import get_tasks_file
+from utils.validation import validate_task_id
 
 
 def mark_done(task_id):

commands/list.py

@@ -1,27 +1,14 @@
 """List tasks command."""
 
 import json
-from pathlib import Path
-
-
-def get_tasks_file():
-    """Get path to tasks file."""
-    return Path.home() / ".local" / "share" / "task-cli" / "tasks.json"
-
-
-def validate_task_file():
-    """Validate tasks file exists."""
-    # NOTE: Validation logic scattered here - should be in utils (refactor bounty)
-    tasks_file = get_tasks_file()
-    if not tasks_file.exists():
-        return []
-    return tasks_file
+from utils.paths import get_tasks_file
+from utils.validation import validate_task_file
 
 
 def list_tasks():
     """List all tasks."""
     # NOTE: No --json flag support yet (feature bounty)
-    tasks_file = validate_task_file()
+    tasks_file = validate_task_file(get_tasks_file())
     if not tasks_file:
         print("No tasks yet!")
         return

test_task.py

@@ -3,8 +3,8 @@
 import json
 import pytest
 from pathlib import Path
-from commands.add import add_task, validate_description
-from commands.done import validate_task_id
+from commands.add import add_task
+from utils.validation import validate_description, validate_task_id
 
 
 def test_validate_description():

utils/__init__.py

@@ -0,0 +1 @@
+# utils package

utils/paths.py

@@ -0,0 +1,8 @@
+"""Shared path helpers for task-cli."""
+
+from pathlib import Path
+
+
+def get_tasks_file() -> Path:
+    """Return the path to the tasks JSON file."""
+    return Path.home() / ".local" / "share" / "task-cli" / "tasks.json"

utils/validation.py

@@ -0,0 +1,37 @@
+"""Shared validation helpers for task-cli."""
+
+
+def validate_description(description: str) -> str:
+    """Validate and normalise a task description.
+
+    Raises:
+        ValueError: if the description is empty or exceeds 200 characters.
+    """
+    if not description:
+        raise ValueError("Description cannot be empty")
+    if len(description) > 200:
+        raise ValueError("Description too long (max 200 chars)")
+    return description.strip()
+
+
+def validate_task_file(tasks_file):
+    """Check whether the tasks file exists.
+
+    Returns:
+        The ``tasks_file`` path if it exists, otherwise an empty list so
+        callers can treat a falsy return as "no tasks yet".
+    """
+    if not tasks_file.exists():
+        return []
+    return tasks_file
+
+
+def validate_task_id(tasks, task_id: int) -> int:
+    """Validate that *task_id* refers to an existing task.
+
+    Raises:
+        ValueError: if *task_id* is out of range.
+    """
+    if task_id < 1 or task_id > len(tasks):
+        raise ValueError(f"Invalid task ID: {task_id}")
+    return task_id