mattdurham/bob:internal:writing-plans

Writing Plans

Overview

Spawn a subagent to write comprehensive implementation plans assuming the engineer has zero context for our codebase. The subagent documents everything: which files to touch, code, testing, docs. Plans are bite-sized tasks following DRY, YAGNI, TDD principles with frequent commits.

Announce at start: "I'm using the writing-plans skill to spawn a planner subagent."

Process:

1. Spawn workflow-planner subagent with background execution
2. Subagent reads design from .bob/state/design.md
3. Subagent checks for spec-driven modules (SPECS.md, NOTES.md) in scope and includes doc update steps
4. Subagent writes plan to .bob/state/plan.md
5. Wait for completion notification

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 to make the test pass" - step
• "Run the tests and make sure they pass" - step
• "Commit" - step

Plan Document Header

Every plan MUST start with this 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 with "function not defined"

Step 3: Write minimal implementation

def function(input):
    return expected

Step 4: Run test to verify it passes

Run: pytest tests/path/test.py::test_name -v Expected: PASS

Step 5: Commit

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
- Reference relevant skills with @ syntax
- DRY, YAGNI, TDD, frequent commits

## Subagent Instructions

Spawn the planner subagent with this exact structure:

Task(subagent_type: "workflow-planner", description: "Create implementation plan", run_in_background: true, prompt: "Read the design from .bob/state/design.md. Check if any directories in scope contain SPECS.md, NOTES.md, TESTS.md, or BENCHMARKS.md — these are spec-driven modules. If found, include explicit steps for updating spec docs alongside code changes.

 Create a concrete, bite-sized implementation plan.

 Each task should be 2-5 minutes and include:
 - Exact file paths
 - Complete code snippets
 - Exact commands to run
 - Expected output
 - TDD approach (test first, then implement)

 Format each task with:
 - Files to create/modify
 - Step-by-step actions (write test, run test, implement, verify, commit)
 - Exact code to write
 - Verification steps

 Write the complete plan to .bob/state/plan.md using the Write tool.")

## Execution Handoff

After subagent completes, report completion:

**"Plan complete and saved to `.bob/state/plan.md`."**