// tabs.js 纯函数测试：不可变风格，验证 add/remove/switchTo
// tabs.js pure-function tests: immutable style, verify add/remove/switchTo
const { test } = require('node:test');
const assert = require('node:assert');
const { add, remove, switchTo } = require('../app/src/main/assets/h5/js/webapp/tabs.js');

test('add 不存在时新增并激活，已存在时不重复', () => {
  let tabs = [];
  tabs = add(tabs, 'a', '云音乐');
  tabs = add(tabs, 'b', '天气');
  tabs = add(tabs, 'a', '云音乐');
  assert.strictEqual(tabs.length, 2, '重复 id 不应重复添加');
  assert.strictEqual(tabs.filter(t => t.active).length, 1, '仅一个激活标签');
  assert.strictEqual(tabs.find(t => t.active).id, 'a', '重复添加应重新激活该 id');
});

test('add 不修改传入数组（不可变）', () => {
  const before = [];
  const after = add(before, 'a', 'x');
  assert.strictEqual(before.length, 0, '原数组不应被改动');
  assert.strictEqual(after.length, 1);
});

test('remove 删除指定标签', () => {
  let tabs = [{ id: 'a', name: 'x', active: false }, { id: 'b', name: 'y', active: true }];
  tabs = remove(tabs, 'a');
  assert.strictEqual(tabs.length, 1);
  assert.strictEqual(tabs[0].id, 'b');
});

test('switchTo 激活指定 id 且不修改原数组', () => {
  const before = [{ id: 'a', name: 'x', active: true }, { id: 'b', name: 'y', active: false }];
  const after = switchTo(before, 'b');
  assert.strictEqual(after.find(t => t.id === 'b').active, true);
  assert.strictEqual(after.filter(t => t.active).length, 1);
  assert.strictEqual(before.find(t => t.id === 'b').active, false, '原数组不应被改动');
});