eslint-config

name	eslint-config
description	Composable ESLint flat config for TypeScript projects. Use config() with presets.base spread to activate baseline, javascript, typescript, imports, jsdoc, unicorn, perfectionist, prettier, regexp, command, packagejson, pnpm, gitignore, node, e18e configs. autoEnable detects installed packages (astro, svelte, lit, storybook, typescript, zod, prettier, vue). Returns Promise<Config[]>. Use overrides/overrides_prepend for project-specific rules.
type	core
library	@stephansama/eslint-config
library_version	0.2.1
sources	["stephansama/packages:core/eslint-config/src/builder.ts","stephansama/packages:core/eslint-config/src/auto.ts","stephansama/packages:core/eslint-config/src/presets.ts","stephansama/packages:core/eslint-config/src/types.ts","stephansama/packages:core/eslint-config/README.md"]

eslint-config

Modular ESLint flat config with 25+ composable configs and auto-detection of installed packages. All configs are additive — pass true to enable or pass an options object to configure.

Setup

// eslint.config.js
import { config, presets } from "@stephansama/eslint-config";

export default config({
  ...presets.base,
});

presets.base includes: baseline, command, e18e, ignore, imports, javascript, jsdoc, node, packagejson, perfectionist, pnpm, prettier, regexp, typescript, unicorn.

config() returns Promise<Config[]> — valid as an ESLint v9 async default export.

Core Patterns

Library package configuration

import { config, presets } from "@stephansama/eslint-config";

export default config({
  ...presets.base,
  ...presets.library, // packagejson with isLibrary: true
  vitest: true,
});

Framework-specific config

import { config, presets } from "@stephansama/eslint-config";

export default config({
  ...presets.base,
  astro: true, // auto-enabled if astro is installed
  svelte: true, // auto-enabled if svelte is installed
  vitest: true,
});

Project-specific rule overrides

import { config, presets } from "@stephansama/eslint-config";

export default config({
  ...presets.base,
  overrides: [
    {
      rules: {
        "unicorn/filename-case": "off",
      },
    },
  ],
  overrides_prepend: [
    {
      ignores: ["generated/**"],
    },
  ],
});

overrides is appended at the end. overrides_prepend is inserted at the start.

Disable auto-detection

export default config({
  ...presets.base,
  autoEnable: false, // only activate what you explicitly set
  typescript: true,
  prettier: true,
});

Common Mistakes

HIGH Config function not awaited in downstream tooling

Wrong:

// Some build tools pass the export directly without awaiting
const result = config({ ...presets.base });
// result is a Promise, not Config[] — ESLint v9 handles this but other tools may not

Correct:

// Explicit await if needed outside ESLint's native async config support
export default await config({ ...presets.base });

Several configs (astro, svelte, json, markdown, css) are async. config() always returns Promise<Config[]>. ESLint v9 flat config natively supports Promise-returning default exports, but other tools consuming the config may not.

Source: core/eslint-config/src/builder.ts

HIGH pnpm config causes errors in non-pnpm projects

Wrong:

// yarn or npm project
export default config({ ...presets.base });
// pnpm: true is in presets.base — enforces catalog: syntax on all version strings

Correct:

export default config({ ...presets.base, pnpm: false });

presets.base includes pnpm: true which activates eslint-plugin-pnpm. It enforces catalog: version syntax and workspace settings. Disable it explicitly in non-pnpm projects.

Source: core/eslint-config/src/presets.ts

HIGH typescript config requires tsconfig.json via projectService

Wrong:

// No tsconfig.json at project root
export default config({ ...presets.base });
// typescript-eslint's projectService cannot find the project → errors on every file

Correct:

export default config({
  ...presets.base,
  typescript: { project: "./tsconfig.json" },
});

The typescript config uses typescript-eslint with projectService. It discovers tsconfig.json automatically, but files outside any tsconfig path produce "file not included in any project" errors. Pass project explicitly in monorepos or non-standard layouts.

Source: core/eslint-config/src/configs/typescript.ts

MEDIUM autoEnable silently activates configs for detected packages

Wrong:

// zod is installed; agent writes config unaware that zod rules are active
export default config({ ...presets.base });
// zod: true is silently enabled by autoEnable

Correct:

// Be explicit or disable autoEnable to see exactly what is active
export default config({ ...presets.base, autoEnable: false, zod: true });

autoEnable: true (default) checks node_modules for astro, svelte, vue/nuxt/vitepress, lit, storybook, prettier, typescript, zod and enables the corresponding config. The final active config is not visible from the config file alone.

Source: core/eslint-config/src/auto.ts:autoEnableMap

References

• All individual config options