eslint-formatter-stylish/index.js

ESLint’s official `stylish` formatter, unofficially published as a standalone module

/**
 * @fileoverview Stylish reporter
 * @author Sindre Sorhus
 */

const chalk = require('chalk'),
	stripAnsi = require('strip-ansi'),
	table = require('text-table');

//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------

/**
 * Given a word and a count, append an s if count is not one.
 * @param {string} word A word in its singular form.
 * @param {int} count A number controlling whether word should be pluralized.
 * @returns {string} The original word with an s on the end if count is not one.
 */
function pluralize(word, count) {
	return count === 1 ? word : `${word}s`;
}

//------------------------------------------------------------------------------
// Public Interface
//------------------------------------------------------------------------------

module.exports = function (results) {
	let output = '\n',
		errorCount = 0,
		warningCount = 0,
		fixableErrorCount = 0,
		fixableWarningCount = 0,
		summaryColor = 'yellow';

	results.forEach(result => {
		const messages = result.messages;

		if (messages.length === 0) {
			return;
		}

		errorCount += result.errorCount;
		warningCount += result.warningCount;
		fixableErrorCount += result.fixableErrorCount;
		fixableWarningCount += result.fixableWarningCount;

		output += `${chalk.underline(result.filePath)}\n`;

		output += `${table(
			messages.map(message => {
				let messageType;

				if (message.fatal || message.severity === 2) {
					messageType = chalk.red('error');
					summaryColor = 'red';
				} else {
					messageType = chalk.yellow('warning');
				}

				return ['', message.line || 0, message.column || 0, messageType, message.message.replace(/([^ ])\.$/u, '$1'), chalk.dim(message.ruleId || '')];
			}),
			{
				align: ['', 'r', 'l'],
				stringLength(str) {
					return stripAnsi(str).length;
				},
			},
		)
			.split('\n')
			.map(el => el.replace(/(\d+)\s+(\d+)/u, (m, p1, p2) => chalk.dim(`${p1}:${p2}`)))
			.join('\n')}\n\n`;
	});

	const total = errorCount + warningCount;

	if (total > 0) {
		output += chalk[summaryColor].bold(['\u2716 ', total, pluralize(' problem', total), ' (', errorCount, pluralize(' error', errorCount), ', ', warningCount, pluralize(' warning', warningCount), ')\n'].join(''));

		if (fixableErrorCount > 0 || fixableWarningCount > 0) {
			output += chalk[summaryColor].bold(['  ', fixableErrorCount, pluralize(' error', fixableErrorCount), ' and ', fixableWarningCount, pluralize(' warning', fixableWarningCount), ' potentially fixable with the `--fix` option.\n'].join(''));
		}
	}

	// Resets output color, for prevent change on top level
	return total > 0 ? chalk.reset(output) : '';
};