exports-subpaths-style

💼 This rule is enabled in the 🎨 stylistic config.

🔧 This rule is automatically fixable by the --fix CLI option.

This rule enforces consistent formatting for the exports field in package.json, ensuring either explicit subpath notation with "." or implicit root-level exports.

Rule Details

The Node.js exports field supports two equivalent formats for defining a single root export:

Explicit format (with "." subpath):

{
  "exports": {
    ".": "./index.js"
  }
}

Implicit format (root-level value):

{
  "exports": "./index.js"
}

Both formats are functionally equivalent for a single root export, but using one consistently improves readability and maintainability across packages.

💡 This rule is especially useful in monorepos where consistency across multiple package.json files is important.

Examples with Default Options (prefer: “explicit”)

Examples of incorrect code with default options:

{
  "exports": "./index.js"
}

{
  "exports": {
    "import": "./index.mjs",
    "require": "./index.cjs"
  }
}

Examples of correct code with default options:

{
  "exports": {
    ".": "./index.js"
  }
}

{
  "exports": {
    ".": {
      "import": "./index.mjs",
      "require": "./index.cjs"
    }
  }
}

{
  "exports": {
    ".": "./index.js",
    "./utils": "./utils.js"
  }
}

Examples with prefer: “implicit”

Examples of incorrect code with { "prefer": "implicit" }:

{
  "exports": {
    ".": "./index.js"
  }
}

{
  "exports": {
    ".": {
      "import": "./index.mjs",
      "require": "./index.cjs"
    }
  }
}

Examples of correct code with { "prefer": "implicit" }:

{
  "exports": "./index.js"
}

{
  "exports": {
    "import": "./index.mjs",
    "require": "./index.cjs"
  }
}

{
  "exports": {
    ".": "./index.js",
    "./utils": "./utils.js"
  }
}

Note: Multiple subpaths always require the explicit object format and are not transformed by this rule.

Options

Name	Description	Type	Choices	Default
`prefer`	Specifies which exports format to enforce.	String	`implicit`, `explicit`	`explicit`

prefer

The prefer option specifies which format to enforce:

"explicit" (default): Requires the "." subpath key for single root exports
"implicit": Prefers the shorthand format without "." for single root exports

{
  "package-json/exports-subpaths-style": [
    "error",
    {
      "prefer": "explicit"
    }
  ]
}

Default: "explicit"

ℹ️ The explicit format is generally recommended as it’s more consistent when packages later add additional subpaths.

This rule is autofixable; run eslint with the --fix option to automatically convert between formats.

When Not to Use It

If your project doesn’t use the exports field or you don’t have a preference for consistency in exports formatting, you can disable this rule.