Bug: False positive no-unused-vars on import in custom.d.ts

Tell us about your environment

Node version: v12.16.2 npm version: v6.13.6 Local ESLint version: v6.8.0 (Currently used) Global ESLint version: Not found OS: macOS 10.15.5

What parser (default, Babel-ESLint, etc.) are you using?

default

Please show your full configuration:

Configuration

module.exports = {
    'env': {
        'es6': true
    },
    'extends': 'eslint:recommended',
    'globals': {
        'process': true
    },
    'settings': {
        'import/resolver': {
            'node': {
                'extensions': ['.js', '.jsx', '.ts', '.tsx']
            }
        }
    },
    'parser': '@typescript-eslint/parser',
    'parserOptions': {
        'project': 'tsconfig.json',
        'sourceType': 'module'
    },
    'plugins': [
        '@typescript-eslint',
        'eslint-plugin-import'
    ],
    'rules': {
        '@typescript-eslint/indent': ['error', 4],
        '@typescript-eslint/no-require-imports': 'error',
        '@typescript-eslint/quotes': [
            'error',
            'single'
        ],
        'comma-dangle': 'error',
        'curly': 'error',
        'eqeqeq': [
            'error',
            'always'
        ],
        'no-trailing-spaces': 'error',
        'no-var': 'error',
        'prefer-const': 'error',
        'no-console': 'error',
        'no-unused-vars': ['error', { 'args': 'none' }],
        'no-throw-literal': 'error',
        'no-trailing-spaces': 'error',
        'import/no-extraneous-dependencies': 'error',
        'import/no-cycle': 'error',
        'import/no-self-import': 'error',
        'import/no-unresolved': 'error'
    },
    'overrides': [{
        'files': ['*.ts', '*.tsx'],
        'rules': {
            '@typescript-eslint/no-unused-vars': [2, { args: 'none' }],
            'no-undef': 'off'
        }
    }]
};

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

Contents of custom.d.ts file:

/* eslint-disable no-unused-vars */
import { Server } from 'ws';

declare global {
    namespace Express {
        interface Request {
            ws?: Server;
        }
    }
}

export {};

eslint -c .eslintrc.js --ext .ts src

What did you expect to happen?

I expected to be able to define the type of ws (imported from @types/ws)

What actually happened? Please include the actual, raw output from ESLint.

Two different failures:

• the import is considered unused
• eslint-disable no-unused-vars has no effect

Are you willing to submit a pull request to fix this bug?

I don’t have a fix to offer at this point.

[yeonjuan]

@ajmas Hi 😃 some eslint rule does not work properly with typescript code. What about use typescript-eslint/no-unused-vars instead?

    'overrides': [{
        'files': ['*.ts', '*.tsx'],
        'rules': {
            'no-unused-vars': 'off', // off the eslint core rule.
            '@typescript-eslint/no-unused-vars': [2, { args: 'none' }],
            'no-undef': 'off'
        }
    }]

[ajmas]

@mdjermanovic thanks. Will do.