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Testing Pascal Triangle Recursive Implementation in javascript-algorithms

This test suite validates the recursive implementation of Pascal’s Triangle coefficient generation in JavaScript. It verifies the correct calculation of triangle rows from index 0 to 7, ensuring accurate numerical sequences and mathematical relationships.

Test Coverage Overview

The test coverage focuses on validating Pascal’s Triangle coefficient calculations across multiple row indices.

Key areas tested include:

Base case validation (row 0)
Sequential row generation from index 1 to 7
Symmetrical number patterns
Correct coefficient calculations

Implementation Analysis

The testing approach employs Jest’s expect assertions to verify the recursive Pascal Triangle implementation.

Testing patterns include:

Sequential test cases using toEqual matcher
Array equality validation
Progressive complexity testing
Systematic row-by-row verification

Technical Details

Testing infrastructure includes:

Jest testing framework
ES6 module imports
Array comparison assertions
Single describe block structure
Multiple expect statements within one test case

Best Practices Demonstrated

The test suite exemplifies quality testing practices through clear organization and thorough validation.

Notable practices include:

Comprehensive edge case coverage
Progressive complexity testing
Clear test case descriptions
Efficient test grouping
Mathematical sequence validation

trekhleb/javascript-algorithms

src/algorithms/math/pascal-triangle/__test__/pascalTriangleRecursive.test.js

            
import pascalTriangleRecursive from '../pascalTriangleRecursive';

describe('pascalTriangleRecursive', () => {
  it('should calculate Pascal Triangle coefficients for specific line number', () => {
    expect(pascalTriangleRecursive(0)).toEqual([1]);
    expect(pascalTriangleRecursive(1)).toEqual([1, 1]);
    expect(pascalTriangleRecursive(2)).toEqual([1, 2, 1]);
    expect(pascalTriangleRecursive(3)).toEqual([1, 3, 3, 1]);
    expect(pascalTriangleRecursive(4)).toEqual([1, 4, 6, 4, 1]);
    expect(pascalTriangleRecursive(5)).toEqual([1, 5, 10, 10, 5, 1]);
    expect(pascalTriangleRecursive(6)).toEqual([1, 6, 15, 20, 15, 6, 1]);
    expect(pascalTriangleRecursive(7)).toEqual([1, 7, 21, 35, 35, 21, 7, 1]);
  });
});