How to disallow empty imports in eslint?

Question

I've been trying to disallow empty imports like this:

import {} from 'module-foo';

Does anybody know how to do it? (I have a TypeScript Node.js project.)

Answer 1

Although there are no predefined rules for it, you can use no-restricted-syntax rule and AST Selectors to disallow this certain syntax:

// .eslintrc.js

module.exports = {
  // ... rest of the options
  rules: {
    // ... rest of the rules
    'no-restricted-syntax': [
      'error',
      {
        selector: 'ImportDeclaration[specifiers.length = 0]',
        message: 'Empty imports are not allowed',
      },
    ],
  }
}

Check this AST Tree to understand how the selector is targeting empty import.