what is fully-fledged promise












4















I was going through the mongoose docs when I Stumbled upon the line saying




Mongoose queries are not promises. They have a .then() function for co
and async/await as a convenience. If you need a fully-fledged promise,
use the .exec() function.




With this example



var query = Band.findOne({name: "Guns N' Roses"});
assert.ok(!(query instanceof Promise));

// A query is not a fully-fledged promise, but it does have a `.then()`.
query.then(function (doc) {
// use doc
});

// `.exec()` gives you a fully-fledged promise
var promise = query.exec();
assert.ok(promise instanceof Promise);

promise.then(function (doc) {
// use doc
});


Now, I didn't get what they meant when they said fully-fledge promise, like for me .then() should be a promoise and then it also allows async and await.



So can someone please explain me what does fully-fledge promise mean?



Reference link: https://mongoosejs.com/docs/promises.html#queries-are-not-promises










share|improve this question























  • "like for me .then() should be a promise" - but what if there is a then but it's not a promise? We call that a thenable.

    – Bergi
    Nov 25 '18 at 18:26


















4















I was going through the mongoose docs when I Stumbled upon the line saying




Mongoose queries are not promises. They have a .then() function for co
and async/await as a convenience. If you need a fully-fledged promise,
use the .exec() function.




With this example



var query = Band.findOne({name: "Guns N' Roses"});
assert.ok(!(query instanceof Promise));

// A query is not a fully-fledged promise, but it does have a `.then()`.
query.then(function (doc) {
// use doc
});

// `.exec()` gives you a fully-fledged promise
var promise = query.exec();
assert.ok(promise instanceof Promise);

promise.then(function (doc) {
// use doc
});


Now, I didn't get what they meant when they said fully-fledge promise, like for me .then() should be a promoise and then it also allows async and await.



So can someone please explain me what does fully-fledge promise mean?



Reference link: https://mongoosejs.com/docs/promises.html#queries-are-not-promises










share|improve this question























  • "like for me .then() should be a promise" - but what if there is a then but it's not a promise? We call that a thenable.

    – Bergi
    Nov 25 '18 at 18:26
















4












4








4


1






I was going through the mongoose docs when I Stumbled upon the line saying




Mongoose queries are not promises. They have a .then() function for co
and async/await as a convenience. If you need a fully-fledged promise,
use the .exec() function.




With this example



var query = Band.findOne({name: "Guns N' Roses"});
assert.ok(!(query instanceof Promise));

// A query is not a fully-fledged promise, but it does have a `.then()`.
query.then(function (doc) {
// use doc
});

// `.exec()` gives you a fully-fledged promise
var promise = query.exec();
assert.ok(promise instanceof Promise);

promise.then(function (doc) {
// use doc
});


Now, I didn't get what they meant when they said fully-fledge promise, like for me .then() should be a promoise and then it also allows async and await.



So can someone please explain me what does fully-fledge promise mean?



Reference link: https://mongoosejs.com/docs/promises.html#queries-are-not-promises










share|improve this question














I was going through the mongoose docs when I Stumbled upon the line saying




Mongoose queries are not promises. They have a .then() function for co
and async/await as a convenience. If you need a fully-fledged promise,
use the .exec() function.




With this example



var query = Band.findOne({name: "Guns N' Roses"});
assert.ok(!(query instanceof Promise));

// A query is not a fully-fledged promise, but it does have a `.then()`.
query.then(function (doc) {
// use doc
});

// `.exec()` gives you a fully-fledged promise
var promise = query.exec();
assert.ok(promise instanceof Promise);

promise.then(function (doc) {
// use doc
});


Now, I didn't get what they meant when they said fully-fledge promise, like for me .then() should be a promoise and then it also allows async and await.



So can someone please explain me what does fully-fledge promise mean?



Reference link: https://mongoosejs.com/docs/promises.html#queries-are-not-promises







javascript node.js mongoose






share|improve this question













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share|improve this question










asked Nov 25 '18 at 17:59









iRohitBhatiaiRohitBhatia

1,414532




1,414532













  • "like for me .then() should be a promise" - but what if there is a then but it's not a promise? We call that a thenable.

    – Bergi
    Nov 25 '18 at 18:26





















  • "like for me .then() should be a promise" - but what if there is a then but it's not a promise? We call that a thenable.

    – Bergi
    Nov 25 '18 at 18:26



















"like for me .then() should be a promise" - but what if there is a then but it's not a promise? We call that a thenable.

– Bergi
Nov 25 '18 at 18:26







"like for me .then() should be a promise" - but what if there is a then but it's not a promise? We call that a thenable.

– Bergi
Nov 25 '18 at 18:26














1 Answer
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That means that the values returned by queries are thenables per the definition of the Promises/A+ spec, but not actual Promise instances. That means they may not have all of the features of promises (for instance, catch and finally methods). Actual Promise instances would be "fully-fledged" promises.



The English term "fully-fledged" means "complete" or "fully developed." It comes from ornithology (or at least, terminology related to birds): A chick (a young bird) that has its adult feathers is "fledged;" if it has all its adult feathers completely covering its down undercoat, it's fully-fledged.






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    4














    That means that the values returned by queries are thenables per the definition of the Promises/A+ spec, but not actual Promise instances. That means they may not have all of the features of promises (for instance, catch and finally methods). Actual Promise instances would be "fully-fledged" promises.



    The English term "fully-fledged" means "complete" or "fully developed." It comes from ornithology (or at least, terminology related to birds): A chick (a young bird) that has its adult feathers is "fledged;" if it has all its adult feathers completely covering its down undercoat, it's fully-fledged.






    share|improve this answer




























      4














      That means that the values returned by queries are thenables per the definition of the Promises/A+ spec, but not actual Promise instances. That means they may not have all of the features of promises (for instance, catch and finally methods). Actual Promise instances would be "fully-fledged" promises.



      The English term "fully-fledged" means "complete" or "fully developed." It comes from ornithology (or at least, terminology related to birds): A chick (a young bird) that has its adult feathers is "fledged;" if it has all its adult feathers completely covering its down undercoat, it's fully-fledged.






      share|improve this answer


























        4












        4








        4







        That means that the values returned by queries are thenables per the definition of the Promises/A+ spec, but not actual Promise instances. That means they may not have all of the features of promises (for instance, catch and finally methods). Actual Promise instances would be "fully-fledged" promises.



        The English term "fully-fledged" means "complete" or "fully developed." It comes from ornithology (or at least, terminology related to birds): A chick (a young bird) that has its adult feathers is "fledged;" if it has all its adult feathers completely covering its down undercoat, it's fully-fledged.






        share|improve this answer













        That means that the values returned by queries are thenables per the definition of the Promises/A+ spec, but not actual Promise instances. That means they may not have all of the features of promises (for instance, catch and finally methods). Actual Promise instances would be "fully-fledged" promises.



        The English term "fully-fledged" means "complete" or "fully developed." It comes from ornithology (or at least, terminology related to birds): A chick (a young bird) that has its adult feathers is "fledged;" if it has all its adult feathers completely covering its down undercoat, it's fully-fledged.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 25 '18 at 18:01









        T.J. CrowderT.J. Crowder

        690k12212261319




        690k12212261319
































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