---

name: eslint-config description: ESLint flat config validation and templates for eslint.config.js files in MetaSaver monorepos. Includes 5 required standards (correct config type for projectType, simple re-export pattern from shared library, flat config filename eslint.config.js, shared config dependency, required npm scripts). Use when creating or auditing eslint.config.js files to ensure correct linting configuration.

ESLint Configuration Skill

This skill provides eslint.config.js templates and validation logic for ESLint flat config setup.

Purpose

Manage eslint.config.js configuration to:

• Configure correct ESLint setup per projectType
• Use shared configuration from @metasaver/core-eslint-config
• Maintain simple re-export pattern (complexity in shared library)
• Ensure consistent linting across monorepo
• Provide required npm scripts for linting

Usage

This skill is invoked by the eslint-agent when:

• Creating new eslint.config.js files
• Auditing existing ESLint configurations
• Validating ESLint configs against standards

Templates

Standard templates are located at:

templates/eslint.config.template.js

The 5 ESLint Standards

Rule 1: Correct Config Type for ProjectType

Each projectType maps to a specific config type from @metasaver/core-eslint-config:

projectType	Config Type	Description
base	base	Minimal config (utilities)
node	node	Node.js backend services
web-standalone	vite-web	Vite React web applications
react-library	react-library	React component libraries

The config type determines which shared configuration is imported.

Rule 2: Simple Re-Export Pattern

Configuration files must use simple re-export only:

export { default } from "@metasaver/core-eslint-config/{type}";

Where {type} is one of: base, node, vite-web, react-library

All ESLint rules and configuration complexity lives in the shared @metasaver/core-eslint-config library. Individual projects must NOT define custom rules or overrides.

Rule 3: Flat Config Filename

Must be named exactly eslint.config.js:

• ESLint flat config expects this filename
• NOT eslint.config.ts, eslint.config.mjs, .eslintrc.js
• Located at workspace root (where package.json is)

Rule 4: Shared Config Dependency

Must have in package.json devDependencies:

{
  "devDependencies": {
    "@metasaver/core-eslint-config": "workspace:*"
  }
}

For monorepos, use workspace:* protocol to reference the shared config package.

Rule 5: Required npm Scripts

Must include lint scripts in package.json:

For packages:

{
  "scripts": {
    "lint": "eslint .",
    "lint:fix": "eslint . --fix"
  }
}

For monorepo root:

{
  "scripts": {
    "lint": "turbo run lint",
    "lint:fix": "turbo run lint:fix"
  }
}

Monorepo root delegates to Turborepo for parallel linting across packages.

Validation

To validate an eslint.config.js file:

1. Read package.json to get metasaver.projectType
2. Map projectType to expected config type
3. Check that eslint.config.js exists at workspace root
4. Parse config and verify re-export pattern
5. Verify shared config dependency exists
6. Check npm scripts (lint and lint:fix)
7. Report violations

Validation Approach

// Rule 1: Map projectType to config type
const typeMap = {
  base: "base",
  node: "node",
  "web-standalone": "vite-web",
  "react-library": "react-library",
};
const expectedType = typeMap[projectType];

// Rule 2: Check re-export pattern
const reExportPattern = new RegExp(
  `export\\s*{\\s*default\\s*}\\s*from\\s*["']@metasaver/core-eslint-config/${expectedType}["']`,
);
if (!reExportPattern.test(content)) {
  errors.push(
    `Rule 2: Must use re-export pattern for config type "${expectedType}"`,
  );
}

// Rule 3: Check filename
if (!path.endsWith("eslint.config.js")) {
  errors.push("Rule 3: Must be named eslint.config.js (flat config)");
}

// Rule 4: Check dependency
const deps = packageJson.devDependencies || {};
if (!deps["@metasaver/core-eslint-config"]) {
  errors.push(
    "Rule 4: Missing @metasaver/core-eslint-config in devDependencies",
  );
}

// Rule 5: Check npm scripts
const scripts = packageJson.scripts || {};
const isMonorepoRoot = packageJson.name === undefined; // Root has no name
if (isMonorepoRoot) {
  if (!scripts.lint?.includes("turbo")) {
    errors.push('Rule 5: Monorepo root must use "turbo run lint"');
  }
} else {
  if (!scripts.lint?.includes("eslint")) {
    errors.push('Rule 5: Missing "lint" script with eslint');
  }
  if (!scripts["lint:fix"]?.includes("eslint")) {
    errors.push('Rule 5: Missing "lint:fix" script with eslint --fix');
  }
}

Repository Type Considerations

• Consumer Repos: Must strictly follow all 5 standards unless exception declared
• Library Repos: May have custom configs for specialized linting needs

Exception Declaration

Consumer repos may declare exceptions in package.json:

{
  "metasaver": {
    "exceptions": {
      "eslint-config": {
        "type": "custom-rules",
        "reason": "Requires custom import ordering rules for legacy codebase"
      }
    }
  }
}

Best Practices

1. Place eslint.config.js at workspace root (where package.json is)
2. Use template matching your projectType
3. Keep re-export simple - delegate complexity to shared config
4. Add shared config dependency with workspace protocol
5. Include both lint and lint:fix scripts
6. Re-audit after making changes

Integration

This skill integrates with:

• Repository type provided via scope parameter. If not provided, use /skill scope-check
• /skill audit-workflow - Bi-directional comparison workflow
• /skill remediation-options - Conform/Update/Ignore choices
• typescript-agent - Coordination with TypeScript configuration
• prettier-agent - Coordination with Prettier formatting