[nodejs:gulp] mocha watch

gulpfile.js

//npm install --save-dev gulp gulp-mocha gulp-util
var gulp = require('gulp');
var mocha = require('gulp-mocha');
var gutil = require('gulp-util');

gulp.task('mocha', function() {
    return gulp.src(['test/**/*.js'], { read: false })
        .pipe(mocha({ reporter: 'spec' }))
        .on('error', gutil.log);
});

gulp.task('watch-mocha', function() {
	gulp.run('mocha');
    gulp.watch(['lib/**', 'test/**'], ['mocha']);
});

gulp.task('default',['watch-mocha'])