index.test.js

const {getAmountsWaysToClimbStairs} = require('.');

/**
 Problem description: You are climbing a stair case. It takes n steps to reach to the top.
 
 Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
 
 Note: Given n will be a positive integer.
 
 Example 1:
 Input: 2
 Output: 2
 Explanation: There are two ways to climb to the top.
 1. 1 step + 1 step
 2. 2 steps
 
 Example 2:
 Input: 3
 Output: 3
 Explanation: There are three ways to climb to the top.
 1. 1 step + 1 step + 1 step
 2. 1 step + 2 steps
 3. 2 steps + 1 step
 */
test('climbing-stairs with 2 stairs steps', () => {
  // Arrange
  const amountSteps = 2;
  
  // Act
  const result = getAmountsWaysToClimbStairs(amountSteps);
  
  // Assert
  expect(result).toEqual(2);
});

test('climbing-stairs with non stairs steps', () => {
  // Arrange
  const amountSteps = 0;
  
  // Act
  const result = getAmountsWaysToClimbStairs(amountSteps);
  
  // Assert
  expect(result).toEqual(1);
});

test('climbing-stairs with 5 steps', () => {
  // Arrange
  const amountSteps = 6;
  
  // Act
  const result = getAmountsWaysToClimbStairs(amountSteps);
  
  // Assert
  expect(result).toEqual(13);
});