test-lint.js

#!/usr/bin/env node
// ---------------------------------------------------------------------------------------------------------------------
// This script is intended to contain all actions pertaining to code style checking, linting and normalization.
// ---------------------------------------------------------------------------------------------------------------------

const chalk = require('chalk'),
    { ESLint } = require('eslint'),

    LINT_SOURCE_DIRS = [
        './test/**/*.js',
        './index.js',
        './lib/**/*.js',
        './npm/**/*.js'
    ];

module.exports = async function (exit) {
    // banner line
    console.info(chalk.yellow.bold('\nLinting files using eslint...'));

    const eslint = new ESLint(),
        results = await eslint.lintFiles(LINT_SOURCE_DIRS),
        errorReport = ESLint.getErrorResults(results),
        formatter = await eslint.loadFormatter();

    // log the result to CLI
    console.info(formatter.format(results));

    (errorReport && !errorReport.length) && console.info(chalk.green('eslint ok!'));

    exit(Number(errorReport && errorReport.length) || 0);
};

// ensure we run this script exports if this is a direct stdin.tty run
!module.parent && module.exports(process.exit);