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Testing Classic Polynomial Evaluation in javascript-algorithms

This test suite validates the classic polynomial evaluation implementation using the naive method, focusing on accuracy across various polynomial coefficients and x-values. The tests ensure correct calculation of polynomial expressions through direct evaluation.

Test Coverage Overview

The test suite provides comprehensive coverage for polynomial evaluation with varying complexity and input values.

Key areas tested include:

Single coefficient polynomials
Multi-term polynomials with different degrees
Polynomials with zero coefficients
Decimal x-values and coefficients
Large value computations

Implementation Analysis

The testing approach employs Jest’s expect assertions to verify precise polynomial calculations. Each test case uses toBe() matcher with high-precision decimal comparisons, demonstrating both floating-point handling and mathematical accuracy requirements.

The implementation follows a systematic pattern of testing increasingly complex polynomials, from simple constant terms to higher-degree expressions with multiple coefficients.

Technical Details

Testing infrastructure:

Jest testing framework
Decimal precision handling
Array-based coefficient representation
Direct function invocation pattern
Floating-point comparison strategy

Best Practices Demonstrated

The test suite exemplifies several testing best practices including comprehensive edge case coverage and precise numerical comparisons.

Notable practices:

Systematic test case organization
Precise floating-point comparisons
Coverage of boundary conditions
Clear input-output relationship validation

trekhleb/javascript-algorithms

src/algorithms/math/horner-method/__test__/classicPolynome.test.js

            
import classicPolynome from '../classicPolynome';

describe('classicPolynome', () => {
  it('should evaluate the polynomial for the specified value of x correctly', () => {
    expect(classicPolynome([8], 0.1)).toBe(8);
    expect(classicPolynome([2, 4, 2, 5], 0.555)).toBe(7.68400775);
    expect(classicPolynome([2, 4, 2, 5], 0.75)).toBe(9.59375);
    expect(classicPolynome([1, 1, 1, 1, 1], 1.75)).toBe(20.55078125);
    expect(classicPolynome([15, 3.5, 0, 2, 1.42, 0.41], 0.315)).toBe(1.1367300651406251);
    expect(classicPolynome([0, 0, 2.77, 1.42, 0.41], 1.35)).toBe(7.375325000000001);
    expect(classicPolynome([0, 0, 2.77, 1.42, 2.3311], 1.35)).toBe(9.296425000000001);
    expect(classicPolynome([2, 0, 0, 5.757, 5.31412, 12.3213], 3.141)).toBe(697.2731167035034);
  });
});