kochwas/tests/unit/quantity-format.test.ts

import { describe, it, expect } from 'vitest';
import { formatQuantity } from '../../src/lib/quantity-format';

describe('formatQuantity', () => {
  it('renders null as empty string', () => {
    expect(formatQuantity(null)).toBe('');
  });

  it('renders whole numbers as integer', () => {
    expect(formatQuantity(400)).toBe('400');
  });

  it('renders near-integer as integer (epsilon 0.01)', () => {
    expect(formatQuantity(400.001)).toBe('400');
    expect(formatQuantity(399.999)).toBe('400');
  });

  it('renders fractional with up to 2 decimals, trailing zeros trimmed', () => {
    expect(formatQuantity(0.5)).toBe('0,5');
    expect(formatQuantity(0.333333)).toBe('0,33');
    expect(formatQuantity(1.1)).toBe('1,1');
    expect(formatQuantity(1.1)).toBe('1,1');
  });

  it('handles zero', () => {
    expect(formatQuantity(0)).toBe('0');
  });
});