gulpfile.js

/*eslint-env node */
'use strict';

var gulp = require('gulp');
var eslint = require('gulp-eslint');

gulp.task('lint', function () {
  // Note: To have the process exit with an error code (1) on
  // lint error, return the stream and pipe to failOnError last.
  return gulp
    .src(['./**/*.js', '!./test/**', '!./node_modules/**'])
    .pipe(
      eslint({
        rules: {
          'space-after-keywords': [2, 'never'],
          indent: [2, 2],
          'valid-jsdoc': 0,
          'func-style': 0,
          'no-use-before-define': 0,
          camelcase: 1,
          'no-unused-vars': 1,
          'no-alert': 1,
          'no-console': 1,
          'no-unused-expressions': 0,
          'consistent-return': 0,
        },
        globals: {
          define: true,
        },
      })
    )
    .pipe(eslint.format())
    .pipe(eslint.failAfterError());
});