import { describe, expect, it } from 'vitest';

import { candidatePorts, WS_PORT_RANGE } from '../../src/background/transport/discovery.js';

describe('candidatePorts', () => {
  it('covers 52000-52016 inclusive by default', () => {
    const ports = candidatePorts();
    expect(WS_PORT_RANGE).toEqual({ start: 52000, end: 52016 });
    expect(ports).toHaveLength(17);
    expect(ports[0]).toBe(52000);
    expect(ports.at(-1)).toBe(52016);
  });

  it('tries the last-known-good port first, then the rest ascending, with no duplicate', () => {
    const ports = candidatePorts(WS_PORT_RANGE, 52009);
    expect(ports[0]).toBe(52009);
    expect(ports).toHaveLength(17);
    expect(ports.filter((p) => p === 52009)).toHaveLength(1);
    expect(ports.slice(1)).toEqual([...ports.slice(1)].sort((a, b) => a - b));
  });

  it('ignores a preferred port outside the range', () => {
    expect(candidatePorts(WS_PORT_RANGE, 40000)).toEqual(candidatePorts());
  });
});