search-algorithms-tests.js

import 'mocha';
import { expect } from 'chai';

const customEquals = (a, b) => a.key === b.key;

export function testSearchAlgorithm(
  searchAlgorithm,
  algorithmName,
  config = { customEquals: true }
) {
  describe(algorithmName, () => {
    const SIZE = 10;

    function createSortedArray() {
      const array = [];
      for (let i = 1; i <= SIZE; i++) {
        array.push(i);
      }
      return array;
    }

    it('works with empty arrays', () => {
      expect(searchAlgorithm([], 1)).to.equal(-1);
    });

    it('finds value at the first position', () => {
      const array = createSortedArray();
      expect(searchAlgorithm(array, 1)).to.equal(0);
    });

    it('finds value at the last position', () => {
      const array = createSortedArray();
      expect(searchAlgorithm(array, SIZE)).to.equal(SIZE - 1);
    });

    it('finds value at different positions', () => {
      const array = createSortedArray();

      for (let value = 1; value <= SIZE; value++) {
        expect(searchAlgorithm(array, value)).to.equal(value - 1);
      }
    });

    if (config.customEquals) {
      it('finds value with custom equals function', () => {
        const array = [{ key: 1 }, { key: 2 }, { key: 3 }];
        expect(searchAlgorithm(array, { key: 2 }, customEquals)).to.equal(1);
      });
    }
  });
}