gulpfile.js

var gulp = require('gulp');
var source = require('vinyl-source-stream');
var nodemon = require('gulp-nodemon');
var mocha = require('gulp-mocha');
var eslint = require('gulp-eslint');
var util = require('gulp-util');
const {dumpError} = require('wriocommon').utils;

function restart_nodemon () {
    if (nodemon_instance) {
        console.log("Restarting nodemon");
        nodemon_instance.emit('restart');
    } else {
        console.log("Nodemon isntance not ready yet")
    }

}

gulp.task('test', function() {
    var grepStatement = util.env.grep ? {grep:util.env.grep} : {};
    return gulp.src('test/**/*.js', {read: false})
        // gulp-mocha needs filepaths so you can't have any plugins before it
        .pipe(mocha(Object.assign({
            reporter: 'dot',
            timeout: 60000,
        },grepStatement)))
        .once('error', function (err) {
            dumpError(err);
            process.exit(1);
        })
        .once('end', function () {
            process.exit();
        });
});

gulp.task('lint', function () {
    // ESLint ignores files with "node_modules" paths.
    // So, it's best to have gulp ignore the directory as well.
    // Also, Be sure to return the stream from the task;
    // Otherwise, the task may end before the stream has finished.
    return gulp.src(['./src/**/*.js*','!./src/client/js/3rdparty/*.js*'])
        // eslint() attaches the lint output to the "eslint" property
        // of the file object so it can be used by other modules.
        .pipe(eslint())
        // eslint.format() outputs the lint results to the console.
        // Alternatively use eslint.formatEach() (see Docs).
        .pipe(eslint.format())
        // To have the process exit with an error code (1) on
        // lint error, return the stream and pipe to failAfterError last.
        .pipe(eslint.failAfterError());
});



var nodemon_instance;

gulp.task('nodemon', function() {

    if (!nodemon_instance) {
        nodemon_instance = nodemon({
            script: 'server.js',
            watch: 'src/__manual_watch__',
            ext: '__manual_watch__',
            verbose: false,
        }).on('restart', function() {
            console.log('~~~ restart server ~~~');
        });
    } else {
        nodemon_instance.emit('restart');
    }

});

gulp.task('default', []);

gulp.task('watch', ['default', 'nodemon'], function() {
    gulp.watch(['src/server/**/*.*'],restart_nodemon);
});