scripts should not be preloaded over other arbitrary preloads. The point is to allow a sort of prioritization by the user via fetchPriority and order of preload calls and by making them use different queues we limit how much control you can have it ordering preloads

Author: gnoff

packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js

@@ -4245,20 +4245,8 @@ export function writePreamble(
   resources.scripts.forEach(flushResourceInPreamble, destination);
   resources.scripts.clear();
 
-  resources.explicitStylesheetPreloads.forEach(
-    flushResourceInPreamble,
-    destination,
-  );
-  resources.explicitStylesheetPreloads.clear();
-
-  resources.explicitScriptPreloads.forEach(
-    flushResourceInPreamble,
-    destination,
-  );
-  resources.explicitScriptPreloads.clear();
-
-  resources.explicitOtherPreloads.forEach(flushResourceInPreamble, destination);
-  resources.explicitOtherPreloads.clear();
+  resources.explicitPreloads.forEach(flushResourceInPreamble, destination);
+  resources.explicitPreloads.clear();
 
   // Write embedding preloadChunks
   const preloadChunks = responseState.preloadChunks;
@@ -4322,14 +4310,8 @@ export function writeHoistables(
   resources.scripts.forEach(flushResourceLate, destination);
   resources.scripts.clear();
 
-  resources.explicitStylesheetPreloads.forEach(flushResourceLate, destination);
-  resources.explicitStylesheetPreloads.clear();
-
-  resources.explicitScriptPreloads.forEach(flushResourceLate, destination);
-  resources.explicitScriptPreloads.clear();
-
-  resources.explicitOtherPreloads.forEach(flushResourceLate, destination);
-  resources.explicitOtherPreloads.clear();
+  resources.explicitPreloads.forEach(flushResourceLate, destination);
+  resources.explicitPreloads.clear();
 
   // Write embedding preloadChunks
   const preloadChunks = responseState.preloadChunks;
@@ -4873,10 +4855,7 @@ export type Resources = {
   precedences: Map<string, Set<StyleResource>>,
   stylePrecedences: Map<string, StyleTagResource>,
   scripts: Set<ScriptResource>,
-  explicitStylesheetPreloads: Set<PreloadResource>,
-  // explicitImagePreloads: Set<PreloadResource>,
-  explicitScriptPreloads: Set<PreloadResource>,
-  explicitOtherPreloads: Set<PreloadResource>,
+  explicitPreloads: Set<PreloadResource>,
 
   // Module-global-like reference for current boundary resources
   boundaryResources: ?BoundaryResources,
@@ -4899,10 +4878,7 @@ export function createResources(): Resources {
     precedences: new Map(),
     stylePrecedences: new Map(),
     scripts: new Set(),
-    explicitStylesheetPreloads: new Set(),
-    // explicitImagePreloads: new Set(),
-    explicitScriptPreloads: new Set(),
-    explicitOtherPreloads: new Set(),
+    explicitPreloads: new Set(),
 
     // like a module global for currently rendering boundary
     boundaryResources: null,
@@ -5189,22 +5165,10 @@ export function preload(href: string, options: PreloadOptions) {
 
       pushLinkImpl(resource.chunks, resource.props);
     }
-    switch (as) {
-      case 'font': {
-        resources.fontPreloads.add(resource);
-        break;
-      }
-      case 'style': {
-        resources.explicitStylesheetPreloads.add(resource);
-        break;
-      }
-      case 'script': {
-        resources.explicitScriptPreloads.add(resource);
-        break;
-      }
-      default: {
-        resources.explicitOtherPreloads.add(resource);
-      }
+    if (as === 'font') {
+      resources.fontPreloads.add(resource);
+    } else {
+      resources.explicitPreloads.add(resource);
     }
     flushResources(request);
   }
@@ -5479,7 +5443,7 @@ function preloadBootstrapScript(
     props,
   };
   resources.preloadsMap.set(key, resource);
-  resources.explicitScriptPreloads.add(resource);
+  resources.explicitPreloads.add(resource);
   pushLinkImpl(resource.chunks, props);
 }
 
@@ -5521,7 +5485,7 @@ function preloadBootstrapModule(
     props,
   };
   resources.preloadsMap.set(key, resource);
-  resources.explicitScriptPreloads.add(resource);
+  resources.explicitPreloads.add(resource);
   pushLinkImpl(resource.chunks, props);
   return;
 }

packages/react-dom/src/__tests__/ReactDOMFloat-test.js

@@ -4131,6 +4131,12 @@ body {
       expect(getMeaningfulChildren(document)).toEqual(
         <html>
           <head>
+            <link
+              rel="preload"
+              as="script"
+              href="highserver"
+              fetchpriority="high"
+            />
             <link
               rel="preload"
               as="style"
@@ -4143,12 +4149,6 @@ body {
               href="autoserver"
               fetchpriority="auto"
             />
-            <link
-              rel="preload"
-              as="script"
-              href="highserver"
-              fetchpriority="high"
-            />
           </head>
           <body>hello</body>
         </html>,
@@ -4166,6 +4166,12 @@ body {
       expect(getMeaningfulChildren(document)).toEqual(
         <html>
           <head>
+            <link
+              rel="preload"
+              as="script"
+              href="highserver"
+              fetchpriority="high"
+            />
             <link
               rel="preload"
               as="style"
@@ -4178,12 +4184,6 @@ body {
               href="autoserver"
               fetchpriority="auto"
             />
-            <link
-              rel="preload"
-              as="script"
-              href="highserver"
-              fetchpriority="high"
-            />
             <link
               rel="preload"
               as="script"