Go Implementation Lens

A VS Code extension that shows interface implementations in Go code using gutter icons (similar to GoLand/IntelliJ), addressing the issue described in golang/go#56695. Features intelligent caching for optimal performance.

Features

• CodeLens for Interfaces: Shows "N implementations" above interface definitions with clickable navigation
• CodeLens for Types: Shows "Implements: Interface1, Interface2..." above struct definitions
• Gutter Icons: Visual indicators in the editor gutter for interfaces and implementations
• Smart Navigation:
  • Single implementation: Navigate directly
  • Multiple implementations: Show quick-pick menu with file locations
• Bidirectional Discovery: Find implementations from interfaces AND find interfaces from implementations
• Intelligent Caching: Document-level caching with automatic invalidation for optimal performance
• Real-time Updates: CodeLens and gutter icons update automatically as you modify code
• Configurable Display: Toggle CodeLens and gutter icons independently

How it Works

The extension uses VS Code's built-in executeImplementationProvider command which leverages gopls (Go language server) to find interface implementations. This provides accurate, bidirectional navigation without custom parsing.

Usage

1. Open a Go file in VS Code
2. Look for CodeLens indicators:
   • Above interfaces: "N implementations"
   • Above types: "Implements: Interface1, Interface2..."
3. Click on the CodeLens to navigate

Requirements

• VS Code 1.74.0 or higher
• Go extension for VS Code (with gopls enabled)

Configuration

• goImplementationLens.enable: Enable/disable the extension
• goImplementationLens.showOnInterfaces: Show implementations on interface definitions
• goImplementationLens.showOnTypes: Show implemented interfaces on type definitions

Development

# Install dependencies
npm install

# Compile
npm run compile

# Watch mode
npm run watch

Testing

Press F5 in VS Code to launch a new Extension Development Host window with the extension loaded.