eslint-formatter-compact/index.js

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

/**
 * @fileoverview Compact reporter
 * @author Nicholas C. Zakas
 */

//------------------------------------------------------------------------------
// Helper Functions
//------------------------------------------------------------------------------

/**
 * Returns the severity of warning or error
 * @param {Object} message message object to examine
 * @returns {string} severity level
 * @private
 */
function getMessageType(message) {
	if (message.fatal || message.severity === 2) {
		return 'Error';
	}
	return 'Warning';
}

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

module.exports = function (results) {
	let output = '',
		total = 0;

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

		total += messages.length;

		messages.forEach(message => {
			output += `${result.filePath}: `;
			output += `line ${message.line || 0}`;
			output += `, col ${message.column || 0}`;
			output += `, ${getMessageType(message)}`;
			output += ` - ${message.message}`;
			output += message.ruleId ? ` (${message.ruleId})` : '';
			output += '\n';
		});
	});

	if (total > 0) {
		output += `\n${total} problem${total !== 1 ? 's' : ''}`;
	}

	return output;
};