Fix downloading a cached zip

src/Zip.php

@@ -155,7 +155,7 @@ protected function cache(): Builder|StreamedResponse
         $disk = Storage::disk(config('zipper.disk'));
 
         if ($disk->exists($filename)) {
-            return $disk->download($filename, $zip->getName());
+            return $disk->download($filename, $zip->getOutputName());
         }
 
         $adapter = $disk->getAdapter();

tests/ZipTest.php

@@ -0,0 +1,102 @@
+<?php
+
+use Aerni\Zipper\Zip;
+use Illuminate\Support\Facades\Storage;
+use STS\ZipStream\Builder;
+use Statamic\Contracts\Assets\Asset;
+use Statamic\Facades\AssetContainer;
+use Statamic\Testing\Concerns\PreventsSavingStacheItemsToDisk;
+use Symfony\Component\HttpFoundation\StreamedResponse;
+
+uses(PreventsSavingStacheItemsToDisk::class);
+
+function makeZip(Asset $asset): Zip
+{
+    return Zip::make([$asset])->filename('my-files');
+}
+
+function cachedZipPath(Zip $zip): string
+{
+    return (new ReflectionMethod($zip, 'create'))->invoke($zip)->getFingerprint().'.zip';
+}
+
+function cacheZipOnDisk(Zip $zip, string $contents): void
+{
+    Storage::disk('cache')->put(cachedZipPath($zip), $contents);
+}
+
+beforeEach(function () {
+    config(['filesystems.disks.test' => [
+        'driver' => 'local',
+        'root' => __DIR__.'/__fixtures__/assets',
+    ]]);
+
+    config(['zipper.disk' => 'cache']);
+
+    Storage::fake('cache');
+
+    $this->container = AssetContainer::make('test')->disk('test')->save();
+});
+
+test('caches the zip to disk when caching is enabled and none is cached yet', function () {
+    config(['zipper.save' => true]);
+
+    $zip = makeZip($this->container->assets()->first());
+
+    expect(Storage::disk('cache')->exists(cachedZipPath($zip)))->toBeFalse();
+
+    $response = $zip->get();
+
+    // Nothing was cached yet, so Zipper builds a fresh zip (a streaming Builder)
+    // and writes it to the cache disk for subsequent requests to reuse.
+    expect($response)->toBeInstanceOf(Builder::class)
+        ->and(Storage::disk('cache')->exists(cachedZipPath($zip)))->toBeTrue();
+});
+
+test('downloads the cached zip from disk when one already exists', function () {
+    config(['zipper.save' => true]);
+
+    $zip = makeZip($this->container->assets()->first());
+
+    // Pretend a previous request already cached this exact zip to disk.
+    cacheZipOnDisk($zip, 'the-cached-zip');
+
+    $response = $zip->get();
+
+    ob_start();
+    $response->sendContent();
+    $streamed = ob_get_clean();
+
+    // We streamed the file that was already on disk rather than building a new
+    // zip, so the response body is the cached file byte-for-byte.
+    expect($response)->toBeInstanceOf(StreamedResponse::class)
+        ->and($streamed)->toBe('the-cached-zip');
+});
+
+test('returns a fresh zip on every request when caching is disabled', function () {
+    config(['zipper.save' => false]);
+
+    $first = makeZip($this->container->assets()->first())->get();
+    $second = makeZip($this->container->assets()->first())->get();
+
+    // Each request builds a new zip and nothing is ever written to the cache disk.
+    expect($first)->toBeInstanceOf(Builder::class)
+        ->and($second)->toBeInstanceOf(Builder::class)
+        ->and($first)->not->toBe($second)
+        ->and(Storage::disk('cache')->allFiles())->toBeEmpty();
+});
+
+test('ignores a cached zip on disk when caching is disabled', function () {
+    config(['zipper.save' => false]);
+
+    $zip = makeZip($this->container->assets()->first());
+
+    // A cached zip exists on disk, but with caching turned off it must not be used.
+    cacheZipOnDisk($zip, 'the-cached-zip');
+
+    $response = $zip->get();
+
+    // Zipper builds a fresh zip (a streaming Builder) instead of downloading the
+    // cached file on disk.
+    expect($response)->toBeInstanceOf(Builder::class);
+});