Targeting Files, Globals & Overrides

Environments and globals

In flat config, languageOptions.globals replaces env, and extra config objects with a files pattern replace overrides. Later objects win for the files they match.

Using overrides

Apply stricter rules to source files but looser rules to tests.

import globals from 'globals';

export default [
  { languageOptions: { globals: globals.browser }, rules: { 'no-console': 'error' } },
  {
    files: ['**/*.test.js'],
    languageOptions: { globals: globals.jest },
    rules: { 'no-console': 'off' },
  },
  { ignores: ['dist/', 'coverage/'] },
];

Output:

Overrides configured: stricter prod, lenient tests

Selective strictness

Test files and scripts often need looser rules. Add a config object with a files pattern instead of duplicating your base config, and use a top-level ignores object for build output.

Quick check

Quick check: How do you apply different rules to test files in flat config?

• Add a config object with a files pattern
• Use the env key
• Rename the files
• Use .eslintignore only