text: const expect = require('chai').expect;
  const solve = require('./1-sub-sum');
  
  describe('Sub-sum Calculator', () => {
      it('Should calculate sub-sum when endIndex is larger than length', () => {
          // Arrange
          let expectedSum = 150;
          let numbers = [10, 20, 30, 40, 50, 60];
          let startIndex = 3;
          let endIndex = 300;
  
          // Act
          let actualSum = solve(numbers, startIndex, endIndex);
  
          // Assert
          // assert.equal(actualSum, expectedSum);
          expect(actualSum).to.equal(expectedSum);
      });
  
      it('Should calculate sub-sum when startIndex is lower than 0', () => {
          // Arrange
          let expectedSum = 60;
          let numbers = [10, 20, 30, 40, 50, 60];
          let startIndex = -100;
          let endIndex = 2;
  
          // Act
          let actualSum = solve(numbers, startIndex, endIndex);
  
          // Assert
          // assert.equal(actualSum, expectedSum);
          expect(actualSum).to.equal(expectedSum);
      });
  
      it('Should return NaN when non array is provided for firt argument', () => {
          expect(solve(10, 1, 2)).to.be.NaN;
          expect(solve(null, 1, 2)).to.be.NaN;
          expect(solve(undefined, 1, 2)).to.be.NaN;
          expect(solve({}, 1, 2)).to.be.NaN;
          expect(solve(true, 1, 2)).to.be.NaN;
      });
  })
  