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Is it possible to use map/filter/reduce inside a promise by returning the result with Promise.resolve?


Is it possible to use map/filter/reduce inside a promise by returning the result with Promise.resolve?

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Is it possible to use map/filter/reduce inside a promise by returning the result with Promise.resolve?
Tag : javascript , By : August
Date : November 24 2020, 03:01 PM

Does that help Yes, that's perfectly reasonable code to have. You could even write it as:
return new Promise((resolve) => {
    resolve(some_list.filter((item) => {
        return item.count > 2;
    }));
});

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How to call a function returning a promise on a result of a promise?


Tag : javascript , By : James Dio
Date : March 29 2020, 07:55 AM
I wish did fix the issue. I found out, that the problem is with mongoose. It wraps the module methods, and promises "get lost" somewhere. The solution to this is to use a sync compare method, or provide a callback.
Also I created an issue with this on github: https://github.com/Automattic/mongoose/issues/4856

Is it possible to simplify promise resolve inside a promise?


Tag : javascript , By : Joe Sweeney
Date : March 29 2020, 07:55 AM
it fixes the issue I've found a way to asynchronously load modules, but the result looks somewhat scary. , Does this count as simpler?
export default Promise.all([
    // asynchronously load modules:
    System.import('./details.js'),
    System.import('./chartHelper.js'),
    System.import('./dateHelper.js')
]).then(promises => 
    Promise.all(promises.map(promise => promise.default))
).then([details, chartHelper, dateHelper] => {
    /* ...code dependent on loaded modules... */
});

Promise resolve not waiting for promise inside it


Tag : javascript , By : George H.
Date : March 29 2020, 07:55 AM
Does that help compareTestRailAndProtractor returns a Promise. You can use async/await within .then() and Promise constructor within for loop to await request callback, which is issue at code at Question, as the for loop does not await the callback function
function addTestCaseToTestRail() {
  return compareTestRailAndProtractor()
    .then(async function(tests) {
        var testsLength = tests.tests.length;
        var url = testRailURL + testRailData.addTestEndPoint;

        for (var i = 0; i < testsLength; i++) {
          await new Promise((resolve, reject) => {
              if (tests.tests[i].id == undefined) {
                var newId = ""
                var options = {
                  url: url,
                  headers: headers,
                  body: {
                    "title": tests.tests[i].name,
                    "custom_jira_component": 465
                  },
                  json: true
                }
                request.post(options, function(err, httpResponse, body) {
                  if (err) {
                    reject(err);
                  }
                  newId = body.id;
                  tests.tests[i].id = newId;
                  resolve();
                });

              } else {
                resolve()
              }    
          });
      }
      return tests
    })
}

function test() {
  addTestCaseToTestRail()
    .then(function(tests) {
      console.log(tests);
    })
    .catch(function(err) {
      console.error(err)
    })
}

test()

How to wait for Promise to resolve before returning a new Promise?


Tag : javascript , By : user165871
Date : March 29 2020, 07:55 AM
wish helps you Your current iteration through signIds's Promises is not being chained with anything else - the .delete() Promises aren't being used anywhere at the moment. It would be better to .map each id to a Promise in an array, then use Promise.all on that array. If errors are handled in the consumer, there's no need to catch in emptyQueue just to throw a new error - instead, just return the Promise chain alone, and avoid the explicit Promise construction anti-pattern:
emptyQueue() {
  return Promise.all(
    this.signIds.map(id => (
      database.collection("signs").doc(id).delete()
    ))
  );
}
this.emptyQueue()
  // ...
  .catch(() => {
    ...
  });

Why does returning Promise.resolve() inside `then` cause two promise creation instead of one?


Tag : javascript , By : Guy Kastenbaum
Date : March 29 2020, 07:55 AM
Hope this helps
Why does returning PromisePlus.resolve() inside then cause one more extra promise creation?
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