Agent Skills: SOLID Generic - TypeScript / Bun / Node.js

SOLID Generic - TypeScript / Bun / Node.js

Agent Workflow (MANDATORY)

Before ANY implementation, use TeamCreate to spawn 3 agents:

1. fuse-ai-pilot:explore-codebase - Analyze project structure and existing patterns
2. fuse-ai-pilot:research-expert - Verify latest TypeScript/Bun docs via Context7
3. mcp__context7__query-docs - Check integration compatibility

After implementation, run fuse-ai-pilot:sniper for validation.

DRY - Reuse Before Creating (MANDATORY)

Before writing ANY new code:

1. Grep the codebase for similar function names, patterns, or logic
2. Check shared locations: modules/cores/lib/, modules/cores/interfaces/, modules/cores/errors/
3. If similar code exists -> extend/reuse instead of duplicate
4. If code will be used by 2+ modules -> create in modules/cores/
5. Extract repeated logic (3+ occurrences) into shared helpers

Absolute Rules (MANDATORY)

1. Files < 100 lines

• Split at 90 lines - Never exceed 100
• Modules < 80 lines
• Services < 60 lines
• Validators < 40 lines

2. Interfaces Separated (Modular MANDATORY)

modules/[feature]/src/interfaces/   # Feature types
  |- user.interface.ts
  \- service.interface.ts
modules/cores/interfaces/            # Shared types
  \- shared.interface.ts

NEVER put interfaces in implementation files. NEVER use flat src/ structure - always modules/.

3. JSDoc Mandatory

/**
 * Parse configuration from file path.
 *
 * @param filePath - Absolute path to config file
 * @returns Parsed configuration object
 * @throws ConfigError if file is invalid
 */
export function parseConfig(filePath: string): Config

SOLID Principles (Detailed Guides)

| # | Principle | Reference | Key Rule | |---|-----------|-----------|----------| | S | Single Responsibility | single-responsibility.md | One file = one reason to change | | O | Open/Closed | open-closed.md | Extend via composition, not modification | | L | Liskov Substitution | liskov-substitution.md | Implementations honor interface contracts | | I | Interface Segregation | interface-segregation.md | Many focused interfaces > one fat interface | | D | Dependency Inversion | dependency-inversion.md | Depend on abstractions, inject dependencies |

See solid-principles.md for overview and architecture-patterns.md for project structure.

Code Templates

| Template | Usage | Max Lines | |----------|-------|-----------| | module.md | TypeScript/Bun module | 80 | | service.md | Service with DI | 60 | | interface.md | TypeScript interfaces | - | | validator.md | Zod validation schemas | 40 | | factory.md | Factory pattern | 60 | | error.md | Custom error classes | 40 | | test.md | Bun test / Vitest | - |

Forbidden

• Files > 100 lines
• Interfaces in implementation files
• Business logic in entry points
• Missing JSDoc on exports
• any type
• Barrel exports (index.ts re-exports)
• Duplicating existing utility without Grep search first
• Copy-pasting logic blocks instead of extracting shared function
• Concrete dependencies without interface abstraction