[Preload] Preload module script entries as modulepreload

A `preload; as=script` hint uses classic-script fetch semantics that mismatch a
`<script type=module>`, so the browser discards the preloaded response. modulepreload
matches the module fetch, with or without SRI.

Author: Kocal

src/Asset/TagRenderer.php

@@ -83,7 +83,9 @@ public function renderScriptTags(string $entryName, ?string $packageName = null,
             $tagAttributes = ['src' => $url, 'type' => 'module'] + $attributes + $this->scriptAttributes;
             $this->applyIntegrity($tagAttributes, $reference, $integrity);
             $tags[] = \sprintf('<script %s></script>', $this->attributes($tagAttributes));
-            $this->preload($url, 'preload', 'script', $reference, $integrity);
+            // modulepreload, not `preload as=script`: the tag is a module, and a classic-script preload
+            // mismatches its credentials/CORS mode so the browser discards it.
+            $this->preload($url, 'modulepreload', null, $reference, $integrity);
         }
 
         return implode('', $tags);

tests/Asset/TagRendererTest.php

@@ -273,8 +273,10 @@ public function testRegistersPreloadLinksOnTheRequestWhenWebLinkIsAvailable()
         }
 
         $this->assertSame(['modulepreload'], $byHref['/build/shared-e5.js']['rels']);
-        $this->assertSame(['preload'], $byHref['/build/app-a1b2.js']['rels']);
-        $this->assertSame('script', $byHref['/build/app-a1b2.js']['as']);
+        // The <script type=module> entry is preloaded as modulepreload, not `preload as=script` (whose
+        // classic-script fetch mode mismatches the module and gets discarded by the browser).
+        $this->assertSame(['modulepreload'], $byHref['/build/app-a1b2.js']['rels']);
+        $this->assertNull($byHref['/build/app-a1b2.js']['as']);
         $this->assertSame(['preload'], $byHref['/build/app-c3.css']['rels']);
         $this->assertSame('style', $byHref['/build/app-c3.css']['as']);
     }