Add expectDownload() and expectDownloads() methods

[pascalbaljet]

This PR adds support for capturing and asserting file downloads.

// Single download
visit('/reports')
    ->expectDownload(fn ($page) => $page->click('a[download]'))
    ->assertFilename('report.pdf')
    ->assertSuccessful();

// Multiple downloads
$downloads = visit('/invoices')
    ->expectDownloads(fn ($page) => $page->click('#download-all'), count: 3);

foreach ($downloads as $download) {
    $download->assertSuccessful();
}

The Download object supports fluent chaining:

visit('/export')
    ->expectDownload(fn ($page) => $page->click('#export'))
    ->assertFilename('data.csv')
    ->assertUrlContains('/exports/')
    ->assertContentContains('id,name,email')
    ->assertSuccessful()
    ->saveAs(storage_path('exports/data.csv'));

You can also access download details directly:

$download->suggestedFilename(); // 'report.pdf'
$download->url();               // 'https://example.com/file.pdf'
$download->contents();          // file contents as string
$download->path();              // temp file path

[nunomaduro]

Does jest or vitest have an API for this?

[pascalbaljet]

Does jest or vitest have an API for this?

From what I found, neither Jest or Vitest support this out of the box. With Dusk, I used a custom browser instance that configures the download behavior via Chrome DevTools:

$devTools = new \Facebook\WebDriver\Chrome\ChromeDevToolsDriver($this->driver);

$devTools->execute('Browser.setDownloadBehavior', [
	'behavior' => 'allow',
	'downloadPath' => $path,
]);

I mostly followed Playwright's approach: https://playwright.dev/docs/api/class-download

[nunomaduro]

can you add docs?

[nunomaduro]

fix tests also.

[pascalbaljet]

I'm not sure why it didn't fail in CI on my fork, but I removed the dependency on the Collection class. Docs PR is ready as well.