@future-widget-lab/record-set/src/libs/record-set/helpers/distinct/distinct.helper.spec.ts

A dedicated data structure for in-memory record collections, offering fluent, immutable APIs for MongoDB-like querying, sorting, and transformation.

import { distinct } from './distinct.helper';

type Person = {
  id: number;
  name: string;
  age: number;
};

const records: Array<Person> = [
  { id: 1, name: 'Alice', age: 30 },
  { id: 2, name: 'Bob', age: 25 },
  { id: 3, name: 'Eve', age: 35 },
  { id: 4, name: 'Bob', age: 40 },
];

describe('Unit | Helper | distinct', () => {
  it('should exist', () => {
    expect(distinct).toBeDefined();
  });

  it('should return distinct values correctly using distinct', () => {
    let expected = ['Alice', 'Bob', 'Eve'];
    let actual = distinct({ field: 'name', records });

    expect(actual).toEqual(expected);

    // @ts-expect-error
    expected = [25, 40];

    actual = distinct({ field: 'age', query: { name: 'Bob' }, records });

    expect(actual).toEqual(expected);
  });
});