snyk/create-implementation-plan

Create Implementation Plan

Creates implementation plans using the official project template with session hand-off support, TDD workflow, and progress tracking.

Quick Start

1. Extract issue ID from branch: git branch --show-current (format: XXX-XXXX)
2. Read Jira issue for context and acceptance criteria
3. Create plan file: ${issueID}_implementation_plan.md (root directory)
4. Create tests.json for test scenario tracking
5. Create mermaid diagrams in docs/diagrams/
6. STOP and wait for user confirmation

Template Location

Use template from: .github/IMPLEMENTATION_PLAN_TEMPLATE.md

Replace all {{TICKET_ID}} and {{TICKET_TITLE}} placeholders with actual values.

Files to Create

| File | Location | Purpose | | ------------------- | ----------------------------------- | ------------------------------------ | | Implementation plan | ${issueID}_implementation_plan.md | Main plan document | | Test tracking | tests.json | Track test scenarios across sessions | | Flow diagrams | docs/diagrams/${issueID}_*.mmd | Mermaid source files |

All these files are gitignored - NEVER commit them.

Key Sections to Complete

1. SESSION RESUME (Critical for hand-off)

• Update Quick Context with ticket info and branch
• Fill Current State table
• List Next Actions
• Update Current Working Files table

2. Phase 1: Planning

• 1.1 Requirements Analysis: List changes, error handling, files to modify/create
• 1.2 Schema/Architecture Design: Add schemas, data structures
• 1.3 Flow Diagrams: Create mermaid files, generate PNGs

3. Phase 2: Implementation (Outside-in TDD)

• Use testing skill
• CRITICAL: use outside-in TDD
• Enforce strict test order:
  1. Smoke tests (E2E behavior)
  2. Integration tests (cross operating system behaviour, integrative behaviour)
  3. Unit tests
• Break into checkpoint steps (completable in one session)
• Each step: tasks, tests to write FIRST, commit message
• Reference test IDs from tests.json
• Add a plan self-check: integration tests must appear before unit tests

4. Phase 3: Review

• Code review prep checklist
• Documentation updates
• Pre-commit checks

5. Progress Tracking

• Update status table at end of each session
• Add entry to Session Log

tests.json Structure

{
  "ticket": "IDE-XXXX",
  "description": "Ticket title",
  "lastUpdated": "YYYY-MM-DD",
  "lastSession": {
    "date": "YYYY-MM-DD",
    "sessionNumber": 1,
    "completedSteps": [],
    "currentStep": "1.1 Requirements Analysis",
    "nextStep": "1.2 Schema Design"
  },
  "testSuites": {
    "unit": {},
    "integration": { "scenarios": [] },
    "regression": { "scenarios": [] }
  }
}

Diagram Creation

1. Create: docs/diagrams/${issueID}_description.mmd
2. Reference PNG in plan: ![Name](docs/diagrams/${issueID}_description.png)

Critical Rules

• NEVER commit implementation plan, tests.json, or plan diagrams
• WAIT for confirmation after creating the plan before implementing
• Use Outside-in TDD - write tests FIRST
• Update progress at end of EVERY session (hand-off support)
• Update Jira with progress comments
• Sync plan changes to Jira ticket description and Confluence (if applicable)

Workflow Integration

This skill is called by implementation when no plan exists. After creating the plan:

1. Present plan summary to user
2. Wait for confirmation
3. implementation continues with Phase 2 (Implementation)