writing-plans

name	writing-plans
description	Use when you have a spec or requirements for a multi-step task, before touching code

Writing Plans

Write comprehensive implementation plans assuming the engineer has zero context. Document everything: which files to touch, code, testing, how to verify. Give the whole plan as bite-sized tasks. DRY. YAGNI. TDD. Frequent commits.

Save plans to: docs/plans/YYYY-MM-DD-<feature-name>.md

Bite-Sized Task Granularity

Each step is one action (2-5 minutes):

• "Write the failing test" - step
• "Run it to make sure it fails" - step
• "Implement the minimal code" - step
• "Run the tests" - step
• "Commit" - step

Plan Document Header

# [Feature Name] Implementation Plan

**Goal:** [One sentence describing what this builds]
**Architecture:** [2-3 sentences about approach]
**Tech Stack:** [Key technologies/libraries]

Task Structure

### Task N: [Component Name]

**Files:**
- Create: `exact/path/to/file.py`
- Modify: `exact/path/to/existing.py:123-145`
- Test: `tests/exact/path/to/test.py`

**Step 1: Write the failing test**
```python
def test_specific_behavior():
    result = function(input)
    assert result == expected
```

**Step 2: Run test to verify it fails**
Run: `pytest tests/path/test.py::test_name -v`
Expected: FAIL

**Step 3: Write minimal implementation**
```python
def function(input):
    return expected
```

**Step 4: Run test to verify it passes**
Expected: PASS

**Step 5: Commit**
```bash
git add tests/path/test.py src/path/file.py
git commit -m "feat: add specific feature"
```

Remember

• Exact file paths always
• Complete code in plan (not "add validation")
• Exact commands with expected output
• DRY, YAGNI, TDD, frequent commits

Execution Handoff

After saving the plan, offer:

1. Subagent-Driven - Dispatch fresh subagent per task, review between tasks
2. Parallel Session - Open new session, batch execution with checkpoints