# Extend Existing Pattern

> Task ID: atlas-extend-pattern
> Agent: Atlas (Design System Builder)
> Version: 1.0.0

## Execution Modes

**Choose your execution mode:**

### 1. YOLO Mode - Fast, Autonomous (0-1 prompts)
- Autonomous decision making with logging
- Minimal user interaction
- **Best for:** Simple, deterministic tasks

### 2. Interactive Mode - Balanced, Educational (5-10 prompts) **[DEFAULT]**
- Explicit decision checkpoints
- Educational explanations
- **Best for:** Learning, complex decisions

### 3. Pre-Flight Planning - Comprehensive Upfront Planning
- Task analysis phase (identify all ambiguities)
- Zero ambiguity execution
- **Best for:** Ambiguous requirements, critical work

**Parameter:** `mode` (optional, default: `interactive`)

---

## Task Definition (AIOX Task Format V1.0)

```yaml
task: extendPattern()
responsável: Uma (Empathizer)
responsavel_type: Agente
atomic_layer: Molecule

**Entrada:**
- campo: target
  tipo: string
  origem: User Input
  obrigatório: true
  validação: Must exist in system

- campo: changes
  tipo: object
  origem: User Input
  obrigatório: true
  validação: Valid modification object

- campo: backup
  tipo: boolean
  origem: User Input
  obrigatório: false
  validação: Default: true

**Saída:**
- campo: modified_file
  tipo: string
  destino: File system
  persistido: true

- campo: backup_path
  tipo: string
  destino: File system
  persistido: true

- campo: changes_applied
  tipo: object
  destino: Memory
  persistido: false
```

---

## Pre-Conditions

**Purpose:** Validate prerequisites BEFORE task execution (blocking)

**Checklist:**

```yaml
pre-conditions:
  - [ ] Target exists; backup created; valid modification parameters
    tipo: pre-condition
    blocker: true
    validação: |
      Check target exists; backup created; valid modification parameters
    error_message: "Pre-condition failed: Target exists; backup created; valid modification parameters"
```

---

## Post-Conditions

**Purpose:** Validate execution success AFTER task completes

**Checklist:**

```yaml
post-conditions:
  - [ ] Modification applied; backup preserved; integrity verified
    tipo: post-condition
    blocker: true
    validação: |
      Verify modification applied; backup preserved; integrity verified
    error_message: "Post-condition failed: Modification applied; backup preserved; integrity verified"
```

---

## Acceptance Criteria

**Purpose:** Definitive pass/fail criteria for task completion

**Checklist:**

```yaml
acceptance-criteria:
  - [ ] Changes applied correctly; original backed up; rollback possible
    tipo: acceptance-criterion
    blocker: true
    validação: |
      Assert changes applied correctly; original backed up; rollback possible
    error_message: "Acceptance criterion not met: Changes applied correctly; original backed up; rollback possible"
```

---

## Tools

**External/shared resources used by this task:**

- **Tool:** file-system
  - **Purpose:** File reading, modification, and backup
  - **Source:** Node.js fs module

- **Tool:** ast-parser
  - **Purpose:** Parse and modify code safely
  - **Source:** .aiox-core/utils/ast-parser.js

---

## Scripts

**Agent-specific code for this task:**

- **Script:** modify-file.js
  - **Purpose:** Safe file modification with backup
  - **Language:** JavaScript
  - **Location:** .aiox-core/scripts/modify-file.js

---

## Error Handling

**Strategy:** retry

**Common Errors:**

1. **Error:** Target Not Found
   - **Cause:** Specified resource does not exist
   - **Resolution:** Verify target exists before modification
   - **Recovery:** Suggest similar resources or create new

2. **Error:** Backup Failed
   - **Cause:** Unable to create backup before modification
   - **Resolution:** Check disk space and permissions
   - **Recovery:** Abort modification, preserve original state

3. **Error:** Concurrent Modification
   - **Cause:** Resource modified by another process
   - **Resolution:** Implement file locking or retry logic
   - **Recovery:** Retry with exponential backoff or merge changes

---

## Performance

**Expected Metrics:**

```yaml
duration_expected: 2-5 min (estimated)
cost_estimated: $0.001-0.003
token_usage: ~1,000-3,000 tokens
```

**Optimization Notes:**
- Parallelize independent operations; reuse atom results; implement early exits

---

## Metadata

```yaml
story: N/A
version: 1.0.0
dependencies:
  - N/A
tags:
  - automation
  - workflow
updated_at: 2025-11-17
```

---


## Description

Add new variant, size, or feature to existing component without breaking compatibility. Maintains consistency with design system patterns.

## Prerequisites

- Component exists
- Design system setup complete
- Tokens available for new variant

## Workflow

### Steps

1. **Load Existing Component** - Read component file and structure
2. **Validate Extension Request** - Check compatibility with existing API
3. **Add New Variant/Size** - Extend props and implementation
4. **Update Styles** - Add new variant styles using tokens
5. **Update Tests** - Add tests for new variant
6. **Update Stories** - Add story for new variant
7. **Update Documentation** - Document new variant
8. **Validate Backward Compatibility** - Ensure existing usage still works

## Output

- Updated component file
- Updated styles
- Updated tests
- Updated documentation

## Success Criteria

- [ ] New variant implemented correctly
- [ ] Backward compatible (existing code works)
- [ ] Tests updated and passing
- [ ] Documentation reflects changes
- [ ] No breaking changes

## Example

```bash
*extend button --variant warning

Atlas: "Adding 'warning' variant to Button..."
✓ Updated Button.tsx (new variant prop)
✓ Updated Button.module.css (warning styles)
✓ Updated Button.test.tsx (warning tests)
✓ Updated Button.stories.tsx (warning story)
✓ Backward compatibility: ✓

Warning variant uses:
  - color: var(--color-warning)
  - color (hover): var(--color-warning-dark)
```

## Notes

- Maintain prop interface compatibility
- Add, don't replace
- Test existing variants still work
- Document migration if API changes