Sync between local and remote files using gulp. Developing your local machine and upload all changes to remote server. Just run `npm install`, fill property fields to `.settings.json` and run `gulp watch`. Tested node v8.7.0

gulpfile.js

const gulp = require('gulp');   //Example version ~3.9.1
const watch = require('gulp-watch'); //Used plugin because it's better. Example version ^5.0.1
const sftp = require('gulp-sftp');  //Example version ^0.1.5
const GulpSSH = require('gulp-ssh'); //Example version ^0.7.0
const fs = require('fs');
const settings = require('./.settings.json'); //credentials hide there

const sftpConfig = {
    host: settings.host,
    user: settings.user,
    remotePath: settings.remotePath,
    key: { 
        location: settings.privatekey 
    }
}
const sshConfig = {
    host: settings.host,
    username: settings.user,
    privateKey: fs.readFileSync(settings.privatekey)
}
const ssh = new GulpSSH({
    ignoreErrors: false,
    sshConfig: sshConfig
});
const targets = settings.targets; //settings property is array type

gulp.task("watch", function() {
	watch(targets, {}, function(obj) {
        if(['change', 'add'].indexOf(obj.event) !== -1) {
            const event = obj.event === 'change' ? 'updating' : 'creating';
            const path = obj.dirname.replace(__dirname + '/', '') + '/';
	    const modifiedSftpConfig = Object.assign({}, sftpConfig);
            modifiedSftpConfig.remotePath += path;
            console.log('---File ' + event + '---');
            gulp.src(obj.path)
                .pipe(sftp(modifiedSftpConfig));
        }
        else if(obj.event === 'unlink') {
            const file = obj.basename;
            let path = obj.dirname.replace(__dirname + '/', '') + '/';
            path = settings.remotePath + path + file;
            console.log('---File removing---');
            ssh.exec('rm ' + path);
        }
	});
});

package.json

{
  "name": "",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "gulp": "~3.9.1",
    "gulp-sftp": "^0.1.5",
    "gulp-ssh": "^0.7.0",
    "gulp-watch": "^5.0.1"
  }
}

settings.json

{
    "host": "123.45.67.89",
    "user": "user",
    "privatekey": "/a/b/c/d",
    "remotePath": "/p/p2/p3/",
    "targets": [
        "/loc1/loc2/loc3/"
    ]
}

Btw, gulp-sshdoesn't like ~mark. So use absolute path without any fancy shortcut marks. Example ~/.ssh/ is not maybe work but if you write /User/user/.ssh/ that work.

EDIT: updated gulpfile.js because of directories problem in remote server.