graphql/jsutils/groupBy.d.ts

A Query Language and Runtime which can target any service.

/**
 * Groups array items into a Map, given a function to produce grouping key.
 *
 * @internal
 */
export declare function groupBy<K, T>(list: ReadonlyArray<T>, keyFn: (item: T) => K): Map<K, ReadonlyArray<T>>;