timing-provider/src/operators/select-most-likely-offset.ts

An implementation of the timing provider specification.

import { OperatorFunction, map, scan } from 'rxjs';

export const selectMostLikelyOffset = (): OperatorFunction<[number, number], [number, number]> => (source) =>
    source.pipe(
        scan<[number, number], [number, number][]>((tuples, tuple) => [...tuples.slice(-59), tuple], []),
        map((tuples) =>
            tuples
                .slice(1)
                .reduce(
                    (tupleWithSmallestRoundTripTime, tuple) =>
                        tupleWithSmallestRoundTripTime[1] < tuple[1] ? tupleWithSmallestRoundTripTime : tuple,
                    tuples[0]
                )
        )
    );