Angular Observable reduce function error "Type 'true' is not assignable to type 'false'."

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I have a code in which the memberships$ is an observable of objects that have a property "role". I want to use reduce function in order to traverse all of them, and if anyone's role is "Collector" I want to return value true. This is the code:

hasCollectorRole$: Observable<boolean> = this.memberships$.pipe(
    map(arr => {
      return arr.reduce((acc, val) => {
        if (val.role == "Collector") {
          acc = true;
        }
        return acc;
      }, false)
    })
  );

This is the error that I get on it:

Type 'true' is not assignable to type 'false'.

How do I fix this?

observable rxjs angular reduce
2 Answers

You should probably use .some() instead of .reduce() if you want to traverse a list and see if any role equals "Collector"

hasCollectorRole$: Observable<boolean> = this.memberships$.pipe(
  map(arr => {
    return arr.some((val) => val.role === "Collector")
  })
);


const testCollector = ['test', 'Collector'];
const testNoCollector = ['test', 'NotCollector'];

console.log('result with Collector', testCollector.some(t => t === 'Collector'));
console.log('result Without Collector', testNoCollector.some(t => t === 'Collector'));

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