Code Delta Visualization Skill
code-delta
Visualize proposed code changes in a structured ASCII format with file tree, impact summary, syntax-highlighted diff, and rationale. Use this skill when proposing refactors, simplifications, or any code modifications.
SKILL.md
Full skill instructions
Code Delta Visualization Skill
When proposing code changes, ALWAYS present them in this structured format:
Format Template
╔══════════════════════════════════════════════════════════════════════════════╗
║ Change #N: [Short descriptive title] ║
╠══════════════════════════════════════════════════════════════════════════════╣
║ ║
║ FILE TREE ║
║ [root path]/ ║
║ ├── path/to/ ║
║ │ └── file1.tsx [ACTION] ±N LOC ║
║ └── path/to/ ║
║ └── file2.ts [ACTION] -N LOC ║
║ ───────────────── ║
║ Total: -N LOC ║
║ ║
╠══════════════════════════════════════════════════════════════════════════════╣
║ IMPACT SUMMARY ║
║ ┌─────────────────────┬──────────────┬──────────────┬─────────┐ ║
║ │ Metric │ Before │ After │ Delta │ ║
║ ├─────────────────────┼──────────────┼──────────────┼─────────┤ ║
║ │ LOC (this change) │ — │ — │ -N │ ║
║ │ Cyclomatic │ N │ N │ -N │ ║
║ │ Cognitive │ N │ N │ -N │ ║
║ │ Dependencies │ [before] │ [after] │ [note] │ ║
║ └─────────────────────┴──────────────┴──────────────┴─────────┘ ║
║ ║
╠══════════════════════════════════════════════════════════════════════════════╣
║ DIFF ║
╚══════════════════════════════════════════════════════════════════════════════╝
--- a/path/to/file1.tsx
+++ b/path/to/file1.tsx
-removed line
+added line
context line
--- a/path/to/file2.ts
+++ b/path/to/file2.ts
-removed line
+added line
╔══════════════════════════════════════════════════════════════════════════════╗
║ RATIONALE ║
║ • Reason 1 ║
║ • Reason 2 ║
║ • Reason 3 ║
╚══════════════════════════════════════════════════════════════════════════════╝
Field Definitions
FILE TREE
- Show relative paths from a common root
- Use tree characters:
├──,└──,│ - Actions:
[MODIFIED],[ADDED],[DELETED],[RENAMED] - Show LOC change per file:
+N LOC,-N LOC,±0 LOC - Include total at bottom
IMPACT SUMMARY
Required metrics:
- LOC (this change): Net lines added/removed
- Cyclomatic Complexity: Number of independent paths through code (if/else, switch cases, loops, &&, ||)
- Cognitive Complexity: How difficult code is to understand (nesting depth, breaks in linear flow, recursion)
- Dependencies: New imports, removed imports, or "Reuse" if using existing
Optional metrics (include when relevant):
- Test Coverage: If tests affected
- Bundle Size: If significant
DIFF
- Use ```diff syntax for red/green highlighting
- Group by file with
--- a/and+++ b/headers - Include minimal context lines for clarity
- Separate files with blank line
RATIONALE
- Bullet points explaining why this change improves the codebase
- Focus on: reduced duplication, reuse, readability, maintainability
Usage
After presenting a change in this format, always end with:
Apply? (y/n)
Wait for user confirmation before making changes.