[WIP] Increase test coverage for image-vision.js to 100%

[Copilot]

• Explore repository structure and understand testing setup
• Review existing image-vision.js code (277 lines with 4 exported functions)
• Review existing minimal test coverage (43 lines, only testing extractImageUrls)
• Create comprehensive test suite for extractImageUrls
• Create tests for processImageContent with mock fetch
• Create tests for analyzeImageWithVision (OpenAI and OpenRouter paths)
• Create tests for generateNaturalReply
• Test error handling scenarios (network errors, API failures, invalid URLs)
• Test caching and rate limiting behaviors
• Test media type handling (URL vs NIP-94)
• Verify 100% coverage achieved

Original prompt

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This section details on the original issue you should resolve

<issue_title>Test coverage for image-vision.js (22.74% → 100%)</issue_title>
<issue_description>## Overview

The image-vision.js handles image processing, vision analysis using OpenRouter API, and integration with Nostr media. At 22.74% coverage, this is one of the lowest-tested critical components.

Current Coverage

• Statements: 22.74%
• Branches: 9.09%
• Functions: 8.33%
• Lines: 22.74%
• Target: 100% coverage

Uncovered Areas

Major untested sections:

• Image download and caching
• Vision API integration
• Image description generation
• Media type handling (URL vs NIP-94)
• Error handling for API failures
• Rate limiting
• Cache management
• Image validation
• Multi-image processing

Key Functionality to Test

1. Image Download

• Downloading from URLs
• Handling different image formats
• Managing download errors
• Caching downloaded images
• Cache hit/miss behavior
• Cache size limits

2. Vision API Integration

• Calling OpenRouter vision API
• Handling API responses
• Processing image descriptions
• API error handling
• Rate limit handling
• Retry logic
• API timeout handling

3. Media Type Handling

• Processing URL-based images
• Processing NIP-94 metadata
• Extracting image URLs
• Handling mixed media types
• Validating media data

4. Image Processing

• Generating descriptions
• Extracting visual features
• Analyzing content
• Formatting results
• Multi-image batching

5. Error Scenarios

• Invalid URLs
• Corrupted images
• API failures
• Network errors
• Missing credentials
• Unsupported formats

Testing Strategy

describe('ImageVision', () => {
  describe('Image Download', () => {
    test('downloads images from URLs');
    test('caches downloaded images');
    test('returns cached images');
    test('handles download errors');
    test('respects cache limits');
    test('validates image formats');
  });

  describe('Vision API Integration', () => {
    test('calls OpenRouter API correctly');
    test('processes API responses');
    test('generates image descriptions');
    test('handles API errors gracefully');
    test('implements retry logic');
    test('respects rate limits');
    test('handles timeouts');
  });

  describe('Media Type Handling', () => {
    test('processes URL-based images');
    test('processes NIP-94 metadata');
    test('extracts image URLs correctly');
    test('handles mixed media types');
    test('validates media data');
  });

  describe('Description Generation', () => {
    test('generates descriptions for single images');
    test('generates descriptions for multiple images');
    test('formats descriptions correctly');
    test('includes relevant visual details');
    test('handles empty responses');
  });

  describe('Error Handling', () => {
    test('handles invalid URLs');
    test('handles corrupted images');
    test('handles API failures');
    test('handles network errors');
    test('handles missing credentials');
    test('handles unsupported formats');
  });

  describe('Integration', () => {
    test('integrates with Nostr media events');
    test('provides context to narrative system');
    test('works with thread context');
    test('handles vision in conversations');
  });
});

Test Fixtures Needed

• Sample image URLs (various formats)
• NIP-94 event examples
• Mock OpenRouter API responses
• Cached image data
• Error response examples
• Invalid media examples
• Multi-image scenarios

Acceptance Criteria

• Image download fully tested
• Vision API integration verified
• Media type handling covered
• Description generation tested
• Error scenarios comprehensive
• Cache management verified
• Overall coverage 100%

Related

• Parent: Increase plugin-nostr test coverage to 100% #39 - Increase plugin-nostr test coverage to 100%
• Related: lib/nostr.js - Nostr event handling
• Related: lib/contextAccumulator.js - Visual context
• See: test/test-image-processing.js, IMAGE_VISION.md

Priority

🔴 HIGH - Vision capabilities are a key differentiator, and API integration is critical. Low coverage (22.74%) presents significant risk.</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #56

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