utils.spec.ts

import { it, expect, describe } from "bun:test";
import { computePagination } from "./utils.js";
import { ZodError } from "zod";

describe('computePagination', () => {
	it('returns correct pagination metadata for first page', () => {
		const result = computePagination(1, 10, 100);
		expect(result).toEqual({
			previous_page: 1,
			current_page: 1,
			next_page: 2,
			total_pages: 10,
		});
	});

	it('returns correct pagination metadata for last page', () => {
		const result = computePagination(10, 10, 100);
		expect(result).toEqual({
			previous_page: 9,
			current_page: 10,
			next_page: 10,
			total_pages: 10,
		});
	});

	it('returns correct pagination metadata for middle page', () => {
		const result = computePagination(5, 10, 100);
		expect(result).toEqual({
			previous_page: 4,
			current_page: 5,
			next_page: 6,
			total_pages: 10,
		});
	});

	it('returns correct pagination metadata when total rows is 0', () => {
		const result = computePagination(1, 10, 0);
		expect(result).toEqual({
			previous_page: 1,
			current_page: 1,
			next_page: 1,
			total_pages: 1,
		});
	});

	it('returns correct pagination metadata when total rows is not provided', () => {
		const result = computePagination(1, 10);
		expect(result).toEqual({
			previous_page: 1,
			current_page: 1,
			next_page: 1,
			total_pages: 1,
		});
	});

	it('throws an error when current page is less than 1', () => {
		expect(() => computePagination(0, 10, 100)).toThrowError(ZodError);
	});

	it('throws an error when rows per page is less than 1', () => {
		expect(() => computePagination(1, 0, 100)).toThrowError(ZodError);
	});
});