Back to Repositories

Testing Stock Trading Algorithm Implementation in javascript-algorithms

This test suite validates the stock trading profit calculation algorithm using an accumulator pattern. It verifies the functionality for finding optimal buy/sell timing across various price scenarios while tracking function visits.

Test Coverage Overview

The test suite provides comprehensive coverage of the stock trading algorithm through multiple test cases.

Tests simple price pairs and single values
Validates ascending and descending price sequences
Checks complex price patterns with multiple peaks and valleys
Verifies function visit counting accuracy
Tests edge cases including single-day prices

Implementation Analysis

The testing approach uses Jest’s function mocking capabilities to track algorithm execution.

The implementation employs visit counting through jest.fn() to verify algorithmic efficiency, while validating profit calculations using expect().toEqual() assertions. Each test case combines profit verification with visit count validation.

Technical Details

Testing Framework: Jest
Mocking Utility: jest.fn()
Assertion Method: expect().toEqual()
Test Structure: Single describe block with comprehensive it() test
Visit Tracking: Function call counting

Best Practices Demonstrated

The test suite exemplifies robust testing practices through systematic validation of both functionality and performance metrics.

Comprehensive edge case coverage
Performance monitoring via visit counting
Clear test case progression from simple to complex scenarios
Consistent assertion patterns
Efficient test organization

trekhleb/javascript-algorithms

src/algorithms/uncategorized/best-time-to-buy-sell-stocks/__tests__/accumulatorBestTimeToBuySellStocks.test.js

            
import accumulatorBestTimeToBuySellStocks from '../accumulatorBestTimeToBuySellStocks';

describe('accumulatorBestTimeToBuySellStocks', () => {
  it('should find the best time to buy and sell stocks', () => {
    let visit;

    expect(accumulatorBestTimeToBuySellStocks([1, 5])).toEqual(4);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks([1], visit)).toEqual(0);
    expect(visit).toHaveBeenCalledTimes(1);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks([1, 5], visit)).toEqual(4);
    expect(visit).toHaveBeenCalledTimes(2);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks([5, 1], visit)).toEqual(0);
    expect(visit).toHaveBeenCalledTimes(2);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks([1, 5, 10], visit)).toEqual(9);
    expect(visit).toHaveBeenCalledTimes(3);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks([10, 1, 5, 20, 15, 21], visit)).toEqual(25);
    expect(visit).toHaveBeenCalledTimes(6);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks([7, 1, 5, 3, 6, 4], visit)).toEqual(7);
    expect(visit).toHaveBeenCalledTimes(6);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks([1, 2, 3, 4, 5], visit)).toEqual(4);
    expect(visit).toHaveBeenCalledTimes(5);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks([7, 6, 4, 3, 1], visit)).toEqual(0);
    expect(visit).toHaveBeenCalledTimes(5);

    visit = jest.fn();
    expect(accumulatorBestTimeToBuySellStocks(
      [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20],
      visit,
    )).toEqual(19);
    expect(visit).toHaveBeenCalledTimes(20);
  });
});