refactor: extract magic values into shared constants file

[gsong]

Summary

Magic values are scattered throughout the codebase, making it harder to maintain consistency and increasing the risk of typos or inconsistent changes. These values should be extracted into a centralized constants file to serve as a single source of truth.

Current State

The following magic values are duplicated across multiple files:

Cache-related constants

• Cache file prefix: "selections-"

  • Used in /Users/george/src/gsong/ccmcp/src/selection-cache.ts:54 (getCacheFilePath function)
  • Used in /Users/george/src/gsong/ccmcp/src/selection-cache.ts:111 (clearCache function)
  • Used in /Users/george/src/gsong/ccmcp/src/cleanup.ts:62 (getAllCacheFiles function)

• Cache version: 1

  • Used in /Users/george/src/gsong/ccmcp/src/selection-cache.ts:8 (SelectionCache interface)
  • Used in /Users/george/src/gsong/ccmcp/src/selection-cache.ts:67 (loadSelections function)
  • Used in /Users/george/src/gsong/ccmcp/src/selection-cache.ts:97 (saveSelections function)
  • Used in /Users/george/src/gsong/ccmcp/src/cleanup.ts:75 (loadCacheFile function)

File extension constants

• Config file extension: ".json"
  • Used in /Users/george/src/gsong/ccmcp/src/mcp-scanner.ts:51 (filtering JSON files)
  • Used in /Users/george/src/gsong/ccmcp/src/mcp-scanner.ts:57 (removing extension)
  • Used in /Users/george/src/gsong/ccmcp/src/cleanup.ts:62 (filtering cache files)
  • Used in /Users/george/src/gsong/ccmcp/src/cleanup.ts:194 (constructing config path)
  • Used in /Users/george/src/gsong/ccmcp/src/cleanup.ts:304 (filtering JSON files)

Directory name constants

• Claude directory: ".claude"

  • Used in /Users/george/src/gsong/ccmcp/src/mcp-scanner.ts:31
  • Used in /Users/george/src/gsong/ccmcp/src/index.ts:176
  • Used in /Users/george/src/gsong/ccmcp/src/index.ts:210

• MCP configs directory: "mcp-configs"

  • Used in /Users/george/src/gsong/ccmcp/src/mcp-scanner.ts:31
  • Used in /Users/george/src/gsong/ccmcp/src/index.ts:176
  • Used in /Users/george/src/gsong/ccmcp/src/index.ts:210

Proposed Solution

Create a new file src/constants.ts with well-named, exported constants:

/**
 * Shared constants used throughout the application
 */

/** Prefix for cache file names */
export const CACHE_FILE_PREFIX = "selections-";

/** File extension for configuration files */
export const CONFIG_FILE_EXTENSION = ".json";

/** Current version of the cache file format */
export const CACHE_VERSION = 1;

/** Name of the Claude configuration directory */
export const CLAUDE_DIR = ".claude";

/** Name of the MCP configurations subdirectory */
export const MCP_CONFIGS_DIR = "mcp-configs";

Benefits

1. Single source of truth: Changes to these values only need to be made in one place
2. Easier maintenance: Clear, searchable constant names make the code more maintainable
3. Better discoverability: Developers can quickly find all configurable values in one file
4. Reduced error risk: Eliminates typos from manual string duplication
5. Better IDE support: Constants can be auto-completed and easily refactored

Implementation Steps

1. Create src/constants.ts with the constants listed above
2. Update all files that use these magic values to import from the constants file:
   • src/selection-cache.ts
   • src/cleanup.ts
   • src/mcp-scanner.ts
   • src/index.ts
   • src/console-selector.ts
   • src/tui/index.tsx (ConfigSelector component)
3. Run tests to ensure no regressions: pnpm run test
4. Run type checking: pnpm run fix

Additional Notes

This refactoring will make future changes (like supporting different cache versions or changing directory structures) much easier and safer to implement.