`require-module-specifiers` conflicts with TypeScript

[remcohaszing]

TypeScript uses the presence of ESM to determine whether a file represents a module or a script. This is true for both TypeScript syntax and JavaScript syntax. The rule require-module-specifiers conflicts with this, by disallowing the export {} syntax.

These TypeScript modules define an unused function:

TypeScript playground

function fn() {}

// This makes it a module
export {}

TypeScript playground

function fn() {}

// This makes it a module.
export const variable = ''

// So this is redundant.
export {}

TypeScript playground

// Imports make it a module
import _ from 'lodash'

function fn() {}

TypeScript scripts define a global function:

TypeScript playground

function fn() {}

TypeScript playground

// Type imports don’t make it a module
import type _ from 'lodash'

function fn() {}

// Type exports don’t make it a module
export type EmptyString = ''

Setting the TypeScript option moduleDetection to force forces all files into modules. This does not affect declaration files.

I suggest to allow export {} if there is no other ESM, excluding type-only imports and exports. There’s also the rule @typescript-eslint.io/no-useless-empty-export

[fisker]

If @typescript-eslint.io/no-useless-empty-export already exists, would you consider disable require-module-specifiers for TS files?

[remcohaszing]

I like unicorn/require-module-specifiers, mostly because it reports empty import specifiers.