Refactor: Extract validation to utils module

[scooke11]

/bounty 100

Description

Input validation logic is currently scattered across different command files (add.py, list.py, done.py). This creates code duplication and makes validation logic harder to maintain and test.

Current State

• validate_description() in commands/add.py
• validate_task_file() in commands/list.py
• validate_task_id() in commands/done.py
• Each command also has duplicate get_tasks_file() helper

Proposed Solution

• Create new utils/validation.py module
• Extract all validation functions to this module
• Create utils/paths.py for shared path helpers like get_tasks_file()
• Update all commands to import and use shared validators
• Ensure NO behavior changes (pure refactor)

Requirements

• Create utils/ directory with proper __init__.py
• Move validation functions to utils/validation.py
• Move path helpers to utils/paths.py
• Update all command imports
• All existing tests must still pass
• No duplicate validation code remains

Acceptance Criteria

• All validation logic in utils/validation.py
• All path helpers in utils/paths.py
• All commands updated to use shared utilities
• Tests still pass (no behavior changes)
• No duplicate validation code in command files

[scooke11]

Test comment from local CLI - checking PAT permissions

[scooke11]

I've analyzed the codebase and I'm ready to tackle this refactoring. Here's my approach:

Problem Understanding

The task-cli project has three validation functions and a shared path helper duplicated across three command files (add.py, list.py, done.py). This creates maintenance burden and testing complexity. The goal is to consolidate these into dedicated utility modules without changing any behavior.

Proposed Changes

1. Create new utils/ package structure:

utils/
├── __init__.py
├── validation.py
└── paths.py

2. Extract to utils/validation.py:

• validate_description(description) from commands/add.py:12-19
• validate_task_file() from commands/list.py:12-18
• validate_task_id(tasks, task_id) from commands/done.py:12-17

All functions will be moved with their exact logic, docstrings, and comments preserved.

3. Extract to utils/paths.py:

• get_tasks_file() helper currently duplicated in all three command files
• Single canonical implementation: Path.home() / ".local" / "share" / "task-cli" / "tasks.json"

4. Update imports in command files:

# commands/add.py
from utils.validation import validate_description
from utils.paths import get_tasks_file

# commands/list.py  
from utils.validation import validate_task_file
from utils.paths import get_tasks_file

# commands/done.py
from utils.validation import validate_task_id
from utils.paths import get_tasks_file

5. Update test imports:
The existing test_task.py imports validate_description and validate_task_id directly. I'll update these to:

from utils.validation import validate_description, validate_task_id

Testing Strategy

• Run existing pytest suite to verify zero behavior changes
• All 4 existing tests must pass unchanged
• The refactor is purely structural - no logic modifications

Implementation Steps

1. Create utils/ directory with __init__.py
2. Create utils/paths.py with get_tasks_file()
3. Create utils/validation.py with all three validators
4. Update imports in commands/add.py
5. Update imports in commands/list.py
6. Update imports in commands/done.py
7. Update imports in test_task.py
8. Remove old validation and path functions from command files
9. Verify tests pass with python -m pytest test_task.py

Verification

After changes:

• ✅ No duplicate get_tasks_file() in any command file
• ✅ No validation logic in command files
• ✅ All 4 tests in test_task.py pass
• ✅ CLI still works identically (add/list/done commands)

I'd be happy to work on this if the approach looks good to you. Let me know if you have any questions or would like me to adjust the approach.