gulpfile.js

const gulp = require('gulp');
const bumper = require('gulp-bump');
const git = require('gulp-git');
const shell = require('gulp-shell');
const fs = require('fs');
const sequence = require('gulp-sequence');
const path = require('path');
const mocha = require('gulp-mocha');
const istanbul = require('gulp-istanbul');
const nsp = require('gulp-nsp');
const plumber = require('gulp-plumber');

gulp.task('nsp', (cb) => {
  nsp({ package: path.resolve('package.json') }, cb);
});

gulp.task('pre-test', () => gulp.src('generators/app/index.js')
    .pipe(istanbul({
      includeUntested: true
    }))
    .pipe(istanbul.hookRequire()));

gulp.task('test', ['pre-test'], (cb) => {
  let mochaErr;

  gulp.src('test/*.js')
    .pipe(plumber())
    .pipe(mocha({ reporter: 'spec' }))
    .on('error', (err) => {
      mochaErr = err;
    })
    .pipe(istanbul.writeReports())
    .on('end', () => {
      cb(mochaErr);
    });
});

gulp.task('bump-patch', bump('patch'));
gulp.task('bump-minor', bump('minor'));
gulp.task('bump-major', bump('major'));

gulp.task('git-commit', () => {
  const v = `update to version ${version()}`;
  gulp.src(['./generators/**/*', './README.md', './package.json', './gulpfile.js', './.travis.yml', './travis/**/*'])
    .pipe(git.add())
    .pipe(git.commit(v));
});

gulp.task('git-push', (cb) => {
  const v = version();
  git.push('origin', 'master', (err) => {
    if (err) return cb(err);
    git.tag(v, v, (err) => {
      if (err) return cb(err);
      git.push('origin', 'master', {
        args: '--tags'
      }, cb);
      return true;
    });
    return true;
  });
});

gulp.task('npm', shell.task([
  'npm publish'
]));

function bump(level) {
  return function () {
    return gulp.src(['./package.json'])
      .pipe(bumper({
        type: level
      }))
      .pipe(gulp.dest('./'));
  };
}

function version() {
  return JSON.parse(fs.readFileSync('package.json', 'utf8')).version;
}

gulp.task('prepublish', ['nsp']);
gulp.task('default', ['static', 'test']);
gulp.task('deploy-patch', sequence('test', 'bump-patch', 'git-commit', 'git-push', 'npm'));
gulp.task('deploy-minor', sequence('test', 'bump-minor', 'git-commit', 'git-push', 'npm'));
gulp.task('deploy-major', sequence('test', 'bump-major', 'git-commit', 'git-push', 'npm'));