@jupiterone/eslint-config

This package provides the standard JupiterOne eslint configuration.

Features

• ESLint 9 flat config support with TypeScript
• Vitest test file linting
• Prettier integration (disables conflicting rules)
• Security rules (prevents invisible character backdoors)
• Node.js 18+ Fetch API globals

Installation

npm install @jupiterone/eslint-config --save-dev

Import Paths

Import Path	Description	Test Framework
@jupiterone/eslint-config/flat	Base config with no test framework	None (add manually)
@jupiterone/eslint-config/flat/vitest	Config with Vitest support (recommended)	Vitest
@jupiterone/eslint-config/flat/jest	Config with Jest support	Jest

React Support

For React/frontend projects, use @jupiterone/eslint-plugin-jupiterone-frontend instead. This package is intended for Node.js backend services.

Usage (ESLint 9 Flat Config - Recommended)

Create an eslint.config.mjs in your project root:

With Vitest (Recommended)

// eslint.config.mjs
import { createConfig } from "@jupiterone/eslint-config/flat/vitest";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
});

With Jest

// eslint.config.mjs
import { createConfig } from "@jupiterone/eslint-config/flat/jest";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
});

Base Only (No Test Framework)

// eslint.config.mjs
import { createConfig } from "@jupiterone/eslint-config/flat";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
});

Custom Test File Patterns

// eslint.config.mjs
import { createConfig } from "@jupiterone/eslint-config/flat/vitest";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
  vitestFiles: [
    "**/*.spec.{ts,tsx}",
    "**/__tests__/**/*.{ts,tsx}",
  ],
});

For Jest, use jestFiles instead:

// eslint.config.mjs
import { createConfig } from "@jupiterone/eslint-config/flat/jest";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
  jestFiles: [
    "**/*.spec.{ts,tsx}",
    "**/__tests__/**/*.{ts,tsx}",
  ],
});

Advanced Usage (Composing Configs)

// eslint.config.mjs
import { defineConfig } from "eslint/config";
import {
  createBaseConfig,
  createVitestConfig,
} from "@jupiterone/eslint-config/flat";

export default defineConfig(
  ...createBaseConfig({ tsconfigRootDir: import.meta.dirname }),
  createVitestConfig(),
  // Add your custom rules
  {
    rules: {
      "no-console": "warn",
    },
  }
);

Using Individual Exports

// eslint.config.mjs
import { defineConfig } from "eslint/config";
import {
  eslint,
  tseslint,
  eslintConfigPrettier,
  globals,
  defaultIgnores,
  typescriptDisabledRules,
  globalRules,
  nodeFetchGlobals,
  vitest,
  vitestFilePatterns,
  vitestRules,
} from "@jupiterone/eslint-config/flat";

// Build your own config using the exported pieces
export default defineConfig(
  defaultIgnores,
  eslint.configs.recommended,
  ...tseslint.configs.recommendedTypeChecked,
  eslintConfigPrettier,
  {
    files: ["**/*.{ts,tsx}"],
    languageOptions: {
      parserOptions: {
        projectService: true,
        tsconfigRootDir: import.meta.dirname,
      },
      globals: {
        ...globals.node,
        ...nodeFetchGlobals,
      },
    },
    rules: typescriptDisabledRules,
  },
  {
    files: vitestFilePatterns,
    plugins: { vitest },
    rules: vitestRules,
    settings: { vitest: { typecheck: true } },
    languageOptions: {
      globals: {
        ...globals.node,
        ...nodeFetchGlobals,
        ...vitest.environments.env.globals,
      },
    },
  },
  { rules: globalRules }
);

Test File Patterns

The Vitest configuration automatically applies to:

• vitest.*.{ts,mts,cts,js,mjs,cjs}
• **/test/**/*.{ts,tsx,mts,cts,js,jsx,mjs,cjs}
• **/*.test.{ts,tsx,mts,cts,js,jsx,mjs,cjs}
• **/__tests__/**/*.{ts,tsx,mts,cts,js,jsx,mjs,cjs}
• **/__mocks__/**/*.{ts,tsx,mts,cts,js,jsx,mjs,cjs}

TypeScript Rules

This config by default uses the upstream recommended typescript eslint rules: https://typescript-eslint.io/users/configs#projects-with-type-checking

Security

The id-match rule is enabled to prevent invisible character backdoors. See The Invisible JavaScript Backdoor for more information.

Migration from v3 to v4

v4 introduces ESLint 9 flat config support and enables stricter TypeScript rules by default. This guide covers upgrading from the legacy .eslintrc format to the new flat config.

Breaking Changes

Change	v3	v4
Config format	.eslintrc / .eslintrc.js	eslint.config.mjs
ESLint version	8.x	9.x
TypeScript rules	Relaxed (many rules disabled)	Strict (upstream recommended)
Test framework	Jest	Vitest (Jest also supported)
Entry point	@jupiterone/eslint-config/node18	@jupiterone/eslint-config/flat/vitest

Prerequisites

1. Node.js 18+ is required
2. ESLint 9.x must be installed
3. TypeScript 5.3+ is recommended

Step 1: Update Dependencies

# Remove old ESLint 8 and legacy plugins
npm uninstall eslint @typescript-eslint/eslint-plugin @typescript-eslint/parser eslint-config-prettier eslint-plugin-react

# Install ESLint 9 and the new config
npm install eslint@^9 @jupiterone/eslint-config@^4 --save-dev

Step 2: Replace Configuration File

Delete your old .eslintrc, .eslintrc.js, or .eslintrc.json file and create a new eslint.config.mjs:

Before (v3 - .eslintrc):

{
  "root": true,
  "extends": ["@jupiterone/eslint-config/node18"],
  "parserOptions": {
    "project": "./tsconfig.json",
    "tsconfigRootDir": "."
  }
}

After (v4 - eslint.config.mjs):

import { createConfig } from "@jupiterone/eslint-config/flat";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
});

Step 3: Configuration Mapping

v3 Extends	v4 Equivalent
@jupiterone/eslint-config/node14	createConfig() (Node 18+ only)
@jupiterone/eslint-config/node16	createConfig() (Node 18+ only)
@jupiterone/eslint-config/node18	createConfig()
@jupiterone/eslint-config/react	Use @jupiterone/eslint-plugin-jupiterone-frontend

Step 4: Handle Stricter TypeScript Rules

v4 enables the full typescript-eslint recommended rules by default. If your codebase has many violations, you have two options:

Option A: Fix violations (recommended)

Run ESLint and fix errors incrementally:

npx eslint . --fix

Option B: Disable specific rules temporarily

Add rule overrides to your config:

import { createConfig } from "@jupiterone/eslint-config/flat";

export default [
  ...createConfig({ tsconfigRootDir: import.meta.dirname }),
  {
    rules: {
      // Disable rules you're not ready to adopt
      "@typescript-eslint/no-explicit-any": "off",
      "@typescript-eslint/no-unsafe-assignment": "off",
      "@typescript-eslint/no-unsafe-member-access": "off",
      "@typescript-eslint/no-unsafe-call": "off",
      "@typescript-eslint/no-unsafe-return": "off",
      "@typescript-eslint/no-unsafe-argument": "off",
    },
  },
];

Step 5: Migrate Test Configuration

If using Vitest (recommended):

import { createConfig } from "@jupiterone/eslint-config/flat/vitest";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
});

If using Jest:

import { createConfig } from "@jupiterone/eslint-config/flat/jest";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
});

If not using a test framework:

import { createConfig } from "@jupiterone/eslint-config/flat";

export default createConfig({
  tsconfigRootDir: import.meta.dirname,
});

Step 6: Update npm Scripts

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

Step 7: Update CI/CD

If you're using eslint --ext .ts,.tsx, remove the --ext flag as it's not supported in ESLint 9:

- eslint --ext .ts,.tsx src/
+ eslint src/

Common Migration Issues

Error: "parserOptions.project" not found

The flat config uses projectService instead of project. This is handled automatically by createConfig().

Error: Cannot find module '@jupiterone/eslint-config/node18'

The legacy entry points have been removed. Use @jupiterone/eslint-config/flat instead.

Error: ESLintRC format detected

Delete your .eslintrc* file. ESLint 9 uses eslint.config.mjs by default.

Many new TypeScript errors appearing

This is expected. v4 enables stricter rules. See Step 4 above for options.

Full Migration Example

Before (v3):

project/
├── .eslintrc.json
├── package.json
└── src/

// .eslintrc.json
{
  "root": true,
  "extends": ["@jupiterone/eslint-config/node18"],
  "parserOptions": {
    "project": "./tsconfig.json",
    "tsconfigRootDir": "."
  },
  "rules": {
    "no-console": "warn"
  }
}

After (v4):

project/
├── eslint.config.mjs
├── package.json
└── src/

// eslint.config.mjs
import { createConfig } from "@jupiterone/eslint-config/flat/vitest";

export default [
  ...createConfig({ tsconfigRootDir: import.meta.dirname }),
  {
    rules: {
      "no-console": "warn",
    },
  },
];