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');
	});
});