TypeScript Configuration Skill

Provides tsconfig.json validation logic for TypeScript configuration with no-barrel architecture support.

Purpose

Configure TypeScript compiler options, path aliases, and module resolution to support:

• Direct module imports via #/* path alias
• Proper baseUrl and paths configuration
• Type checking and compilation settings
• Module resolution for ESM

The 5 TypeScript Configuration Standards

Rule	Requirement	Details
1	Compiler options	target: "ES2022", module: "ESNext", moduleResolution: "node"
2	Path alias configuration	baseUrl: ".", paths with "#/": ["./src/"]
3	Type generation	declaration: true, declarationMap: true
4	Strict mode	strict: true
5	Output configuration	outDir: "./dist", rootDir: "./src"

Rule 1: Compiler Options

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "ESNext",
    "moduleResolution": "node",
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  }
}

Rule 2: Path Alias Configuration (No-Barrel Architecture)

{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "#/*": ["./src/*"]
    }
  }
}

Critical: baseUrl MUST be present when using paths. The #/* alias enables direct module imports without barrel files.

Rule 3: Type Generation

{
  "compilerOptions": {
    "declaration": true,
    "declarationMap": true
  }
}

Rule 4: Strict Mode

{
  "compilerOptions": {
    "strict": true
  }
}

Rule 5: Output Configuration

{
  "compilerOptions": {
    "outDir": "./dist",
    "rootDir": "./src"
  }
}

Validation

Validation checks (pseudo-code):

// Rule 1: Compiler options
validate(config.compilerOptions?.target === "ES2022");
validate(config.compilerOptions?.module === "ESNext");
validate(config.compilerOptions?.moduleResolution === "node");

// Rule 2: Path alias configuration (No-Barrel Architecture)
if (config.compilerOptions?.paths) {
  if (!config.compilerOptions?.baseUrl) {
    errors.push("Rule 2: baseUrl must be present when using paths");
  }
  if (!config.compilerOptions?.paths?.["#/*"]) {
    errors.push("Rule 2: Missing paths['#/*'] for no-barrel imports");
  } else {
    const pathMapping = config.compilerOptions.paths["#/*"];
    if (!Array.isArray(pathMapping) || pathMapping[0] !== "./src/*") {
      errors.push("Rule 2: paths['#/*'] must point to ['./src/*']");
    }
  }
}

// Rule 3: Type generation
validate(config.compilerOptions?.declaration === true);
validate(config.compilerOptions?.declarationMap === true);

// Rule 4: Strict mode
validate(config.compilerOptions?.strict === true);

// Rule 5: Output configuration
validate(config.compilerOptions?.outDir === "./dist");
validate(config.compilerOptions?.rootDir === "./src");

Common Violations

Violation	Issue	Remediation
Missing baseUrl	paths defined without baseUrl	Add "baseUrl": "." to compilerOptions
Missing #/* path mapping	No path alias for no-barrel imports	Add "paths": { "#/": ["./src/"] }
Incorrect path mapping	#/* points to wrong directory	Update paths["#/"] to ["./src/"]
Missing declaration	No type generation configured	Add "declaration": true, "declarationMap": true
Non-strict mode	TypeScript not in strict mode	Add "strict": true

Best Practices

1. Always set baseUrl when using paths
2. Use #/* alias for no-barrel architecture
3. Enable strict mode for type safety
4. Generate declaration files for library packages
5. Re-audit after making changes

Integration

• Repository type: Use /skill scope-check if not provided
• Workflow: /skill audit-workflow
• Remediation: /skill remediation-options
• Related: root-package-json-config, vitest-config, vite-config