A simple gulp stream plugin for counting warnings from gulp-eslint and call a callback function when the number rises above a threshold you set.

npm install gulp-eslint-threshold

'use strict';
var gulp = require('gulp'),
	eslint = require('gulp-eslint'),
	eslintThreshold = require('gulp-eslint-threshold');
gulp.task('eslint', function() {
	var thresholdWarnings = 3;
	return gulp.src(['**/*.js', '!node_modules/**'])
		.pipe(eslint())
		.pipe(eslint.format())
		.pipe(eslintThreshold.afterWarnings(thresholdWarnings, function (numberOfWarnings) {
			throw new Error('ESLint warnings (' + numberOfWarnings + ') equal to or greater than the threshold (' + thresholdWarnings + ')');
		}));
});
gulp.task('default', ['eslint']);

afterWarnings(minWarnings, callbackFunction)

• minWarnings, a number for the threshold.
• callbackFunction(eslintWarnings), a callback function for when the threshold is met. The argument eslintWarnings is the number of warnings found by ESLint.

afterErrors(minErrors, callbackFunction)

• minErrors, a number for the threshold.
• callbackFunction(eslintErrors), a callback function for when the threshold is met. The argument eslintErrors is the number of errors found by ESLint.