Destructuring promise callback

Question

There is a promise in my code:

req.getValidationResult()
        .then(result => {
            let errors = result.array();
            if (errors.length) {
                return res.status(400).json({ errors: errors });
            }
            
            return next();
        });

I'd like to know is there any variants to destructure my 'result' variable on then call (something like .then({result.array(): errors} =>...) and not to make let errors = result.array(); assignment.

Answer 1

I believe it's impossible with the native promise. You can change this code a bit:

req.getValidationResult()
        .then(({array}) => array())
        .then(errors => {
            if (errors.length) {
                return res.status(400).json({ errors: errors });
            }
            return next();
        });

Or you can use bluebird. It has a call method:

req.getValidationResult()
        .call('array')
        .then(errors => {
            if (errors.length) {
                return res.status(400).json({ errors: errors });
            }
            return next();
        });

But in the case you need to cast your promise to Bluebird promise