# Implementation Plan: Logger Color Detection

## Overview

This implementation plan converts the logger color detection design into discrete coding tasks. The approach focuses on adding color support detection to the existing `defaultLogger` function in `src/helpers.ts` while maintaining backward compatibility. The implementation will be incremental, with testing integrated at each step to catch errors early.

## Tasks

- [x] 1. Implement color support detection function
  - Create `supportsColor()` function that checks environment variables and TTY status
  - Implement caching mechanism for detection result
  - Handle FORCE_COLOR, NO_COLOR, and TTY detection with proper precedence
  - Handle edge cases (undefined stdout, missing env vars)
  - _Requirements: 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 4.1, 4.2, 4.3, 4.4, 5.1, 5.2, 5.3, 5.4, 5.5_

- [ ]* 1.1 Write property test for FORCE_COLOR behavior
  - **Property 1: FORCE_COLOR enables colors**
  - **Validates: Requirements 1.5**

- [ ]* 1.2 Write property test for NO_COLOR behavior
  - **Property 2: NO_COLOR disables colors**
  - **Validates: Requirements 1.6**

- [ ]* 1.3 Write property test for safe error handling
  - **Property 6: Safe error handling**
  - **Validates: Requirements 4.2**

- [ ]* 1.4 Write unit tests for color detection edge cases
  - Test FORCE_COLOR precedence over NO_COLOR
  - Test undefined stdout handling
  - Test error in detection defaults to plain text
  - Test caching behavior
  - Test non-TTY with FORCE_COLOR
  - _Requirements: 1.7, 4.1, 4.3, 4.4, 5.5_

- [x] 2. Implement color formatter utility
  - Create `colorize()` helper function that conditionally applies ANSI codes
  - Accept text, color code, and enabled flag as parameters
  - Return formatted text with ANSI codes when enabled, plain text otherwise
  - _Requirements: 2.1, 2.2_

- [ ]* 2.1 Write property test for colors when enabled
  - **Property 3: Colors present when enabled**
  - **Validates: Requirements 2.1**

- [ ]* 2.2 Write property test for no colors when disabled
  - **Property 4: No colors when disabled**
  - **Validates: Requirements 2.2**

- [x] 3. Refactor defaultLogger to use color detection
  - Update `defaultLogger` function to call `supportsColor()` at the start
  - Replace all hardcoded ANSI escape codes with calls to `colorize()`
  - Maintain identical output structure and information content
  - Preserve existing function signature and behavior
  - _Requirements: 2.1, 2.2, 2.3, 2.4, 3.1, 3.2, 3.3, 3.4_

- [ ]* 3.1 Write property test for content preservation
  - **Property 5: Content preservation**
  - **Validates: Requirements 2.3, 2.4**

- [ ]* 3.2 Write unit test for backward compatibility
  - Test that output matches expected format in color-supporting environments
  - _Requirements: 3.4_

- [x] 4. Checkpoint - Ensure all tests pass
  - Ensure all tests pass, ask the user if questions arise.

## Notes

- Tasks marked with `*` are optional and can be skipped for faster MVP
- Each task references specific requirements for traceability
- Property tests validate universal correctness properties with minimum 100 iterations
- Unit tests validate specific examples and edge cases
- The implementation maintains full backward compatibility with existing code