Arbeitet Funktion nicht mit Versprechen

Question

Ich versuche, diesen Code:

function addNewCars(req, res) { 
    let CarsList = req.body; 
    carListParsing(carList) 
     .then(function() { 
     console.log('OK'); 
     res.status(200).send('OK'); 
    }).catch(function (err) { 
     res.status(200).send(err); 
    }); 
} 

function carListParsing (data) { 
    return new Promise(function (resolve, reject) { 

     let newCar = {}; 
     newCar.name = data.car_name; 
     validateCar(newCar).then(function (data) { 
      console.log('validate result1: ', data); //this line doesn't show 
      //if I get validation result, I can use next function createCat() 
      resolve(data); 
     }).catch(function (err) { 
      reject(err); 
     }); 
    }); 
} 

function validateCar(data) { 
    db.cars.findAll({where: {name: data.name}}).then(function (org) { 
     if (org.length < 1) { 
      console.log('validate1: OK'); //work 
      return data; 
     } else { 
      console.log('validate2: already exist'); //work 
      return new Error('The ' + data.name + ' car is already exist.'); 
     } 
    }).catch(function (err) { 
     return err; 
    }); 
} 

I neet Daten überprüfen => Auto Namen, wenn Auto nicht dann neues Auto vorhanden schaffen und nächste Logik, zB Park Auto durchführen. Wenn das Auto gefunden wurde, dann führe das Funktionsparkauto aus.

Answer 1

Vermeiden Sie die Promise constructor antipattern in carListParsing und return Ihr Ergebnis Versprechen von validateCar!

function addNewCars(req, res) { 
    // CarsList is a typo 
    carListParsing(req.body) 
    .then(function() { 
     console.log('OK'); 
     res.status(200).send('OK'); 
    }, function (err) { // more appropriate than catch 
     res.status(200).send(err); 
    }); 
} 

function carListParsing (data) { 
    let newCar = { 
     name: data.car_name 
    }; 
    // don't call `new Promise` 
    return validateCar(newCar).then(function (data) { 
     console.log('validate result1: ', data); //this line doesn't show 
     // if I get validation result, I can use next function createCat() 
     return data; // don't resolve 
    }); 
} 

function validateCar(data) { 
    return db.cars.findAll({where: {name: data.name}}).then(function (org) { 
// ^^^^^^ 
     if (org.length < 1) { 
      console.log('validate1: OK'); //work 
      return data; 
     } else { 
      console.log('validate2: already exist'); //work 
      throw new Error('The ' + data.name + ' car is already exist.'); 
//   ^^^^^ probably what you actually wanted 
     } 
    }) // don't ignore errors 
}