在节点js中使用async await？

我正在尝试实现async / await模块。在function2中，如果用户不在，我想在那里停止执行。我不想执行功能3，如果用户在场，我想执行function3

    const function1() {
                 //code
                 return a
                }

    const function2= (a,email) => model.user.findOne({ email:email}).then((user) => {
                    if (!user) {
                        ****// want to stop execution here****
                    } else {
                        //update details of user
                    }

                    return dealer;
                });


 const function 3 = function(dealer) {
            //mail sending
   };

 exports.mailer = async(email,callback) => {
                try {
                    var a =await function1();
                    var dealer =await function2(a,email);  //stop execution here       
                    var res  = await function 3(dealer);
                        await callback(res);
                    }catch (err){
                      callback(err);
                    }
                }

在节点js中使用async await？

我正在尝试实现async / await模块。在function2中，如果用户不在，我想在那里停止执行。我不想执行功能3，如果用户在场，我想执行function3

    const function1() {
                 //code
                 return a
                }

    const function2= (a,email) => model.user.findOne({ email:email}).then((user) => {
                    if (!user) {
                        ****// want to stop execution here****
                    } else {
                        //update details of user
                    }

                    return dealer;
                });


 const function 3 = function(dealer) {
            //mail sending
   };

 exports.mailer = async(email,callback) => {
                try {
                    var a =await function1();
                    var dealer =await function2(a,email);  //stop execution here       
                    var res  = await function 3(dealer);
                        await callback(res);
                    }catch (err){
                      callback(err);
                    }
                }