Argthtjtr

I have tried to trim down my use case in below example.

I am stuck at the a point where I need to pass the result of operator which should have

• input passed of operator


• and result of the defer operation inside the
  concatMap.

so that I can use it next operator.

import { of, from, defer } from 'rxjs';

import { mergeMap, filter, concatMap, map, reduce } from 'rxjs/operators';



const list: number = [1, 2, 3, 4, 5, 6];



function testFunctionPromise(value: number) {

  return () => {

    return new Promise((resolve, reject) => {

      setTimeout(() => {

        return resolve('processed-value ' + value);

      }, 1000);

    });

  }

}





from(list)

  .pipe(

    filter((item: number) => item % 2 === 0),

    concatMap((item: number) => {

      const pf = testFunctionPromise(item);



      /**

       *  QUESTION: from this step I want to pass both

       *  the result of defer(pf); and item

       * 

       *  as

       * 

       *  return { item: <result of defer(pf)> }

       * 

       */

      return defer(pf);

    }),

    reduce((acc: any, item: any) => acc.concat([item]), )

  )

  .subscribe(

    data => console.log({ data }),

    error => console.error({ error })

  )

url: https://stackblitz.com/edit/rxjs-defer?file=index.ts

concatMap((item: number) => {

  return defer(testFunctionPromise(item)).pipe(

    map(result => ({

      item: result

    })),

  );

})

Or maybe if you want to use item as a property:

map(result => ({

  [item]: result

})),