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Testing Binary Number Bit Length Calculation in javascript-algorithms

This test suite validates the bitLength function which calculates the number of bits required to represent a binary number. The tests verify correct bit length calculation across various binary inputs, from simple single-bit numbers to more complex multi-bit representations.

Test Coverage Overview

The test coverage focuses on validating the bitLength function’s ability to accurately count significant bits in binary numbers.

Key test cases include:

Zero value (0b0)
Single bit numbers (0b1)
Numbers with leading zeros (0b01, 0b0101)
Multi-bit numbers (0b10101, 0b11110101)
Edge cases with extended leading zeros (0b00011110101)

Implementation Analysis

The testing approach utilizes Jest’s describe/it pattern for structured test organization. The implementation employs binary literal notation (0b prefix) to clearly express test inputs, paired with Jest’s expect().toBe() assertions for precise output validation.

The tests systematically verify the function’s handling of different binary number patterns, ensuring consistent behavior regardless of leading zeros.

Technical Details

Testing tools and setup:

Jest testing framework
Binary literal syntax (0b prefix)
Expect assertions for exact matching
Single describe block with multiple test cases
Direct import of bitLength function

Best Practices Demonstrated

The test suite exemplifies several testing best practices including clear test case organization, comprehensive input coverage, and explicit expected outputs.

Notable practices:

Progressive complexity in test cases
Explicit binary notation for clarity
Coverage of edge cases and leading zeros
Consistent assertion pattern
Focused test scope

trekhleb/javascript-algorithms

src/algorithms/math/bits/__test__/bitLength.test.js

            
import bitLength from '../bitLength';

describe('bitLength', () => {
  it('should calculate number of bits that the number is consists of', () => {
    expect(bitLength(0b0)).toBe(0);
    expect(bitLength(0b1)).toBe(1);
    expect(bitLength(0b01)).toBe(1);
    expect(bitLength(0b101)).toBe(3);
    expect(bitLength(0b0101)).toBe(3);
    expect(bitLength(0b10101)).toBe(5);
    expect(bitLength(0b11110101)).toBe(8);
    expect(bitLength(0b00011110101)).toBe(8);
  });
});