// The tab keeps its DOM between visits (app.js loads a component once and marks
// it data-loaded), so whatever the last run rendered stays on screen. An
// illustration from a previous generation sat under an empty form as though it
// were output for a topic nobody had typed, and only a full page refresh
// cleared it.
const test = require('node:test');
const assert = require('node:assert/strict');
const fs = require('node:fs');
const path = require('node:path');

const ui = fs.readFileSync(path.join(__dirname, '..', 'public/js/myResources.js'), 'utf8');

test('a new generation starts from a clean result area', () => {
  assert.match(ui, /function clearResults\(\)/);
  const gen = ui.slice(ui.indexOf('function runGenerate'), ui.indexOf('function reportSearches'));
  assert.match(gen, /clearResults\(\);/, 'generate clears before it runs');
});

test('a modification clears it too', () => {
  const start = ui.indexOf('function runModify');
  const mod = ui.slice(start, ui.indexOf('function renderRow', start));
  assert.match(mod, /clearResults\(\);/);
});

test('reopening the tab clears it, but the first visit does not need to', () => {
  const tab = ui.slice(ui.indexOf("e.detail.tab !== 'myresources'"), ui.indexOf('var available'));
  assert.match(tab, /else clearResults\(\);/,
    'only on a revisit — on the first visit there is nothing to clear and init() has not run');
});

test('clearing covers every container a run writes into', () => {
  const fn = ui.slice(ui.indexOf('function clearResults'), ui.indexOf('function runGenerate'));
  for (const id of ['mr-images', 'mr-searches', 'mr-image-failures']) {
    assert.ok(fn.includes(id), id + ' is not cleared');
  }
  assert.match(fn, /status\(''\)/, 'the status line is part of the debris');
  // textContent, not innerHTML: these hold model-derived text and image nodes.
  assert.match(fn, /el\.textContent = ''/);
});