fix: should inject prefetch startup in entry chunk instead of runtime chunk

crates/rspack_plugin_runtime/src/chunk_prefetch_preload.rs

@@ -1,6 +1,6 @@
 use rspack_core::{
-  ChunkGroupOrderKey, ChunkUkey, Compilation, CompilationAdditionalTreeRuntimeRequirements, Plugin,
-  RuntimeGlobals,
+  ChunkGroupOrderKey, ChunkUkey, Compilation, CompilationAdditionalChunkRuntimeRequirements,
+  CompilationAdditionalTreeRuntimeRequirements, Plugin, RuntimeGlobals,
 };
 use rspack_error::Result;
 use rspack_hook::{plugin, plugin_hook};
@@ -14,14 +14,22 @@ use crate::runtime_module::{
 #[derive(Debug, Default)]
 pub struct ChunkPrefetchPreloadPlugin;
 
-#[plugin_hook(CompilationAdditionalTreeRuntimeRequirements for ChunkPrefetchPreloadPlugin)]
-async fn additional_tree_runtime_requirements(
+#[plugin_hook(CompilationAdditionalChunkRuntimeRequirements for ChunkPrefetchPreloadPlugin)]
+async fn additional_chunk_runtime_requirements(
   &self,
   compilation: &mut Compilation,
   chunk_ukey: &ChunkUkey,
   runtime_requirements: &mut RuntimeGlobals,
 ) -> Result<()> {
   let chunk = compilation.chunk_by_ukey.expect_get(chunk_ukey);
+  if compilation
+    .chunk_graph
+    .get_number_of_entry_modules(chunk_ukey)
+    == 0
+  {
+    return Ok(());
+  }
+
   if let Some(startup_child_chunks) =
     chunk.get_children_of_type_in_order(&ChunkGroupOrderKey::Prefetch, compilation, false)
   {
@@ -33,7 +41,16 @@ async fn additional_tree_runtime_requirements(
       Box::new(ChunkPrefetchStartupRuntimeModule::new(startup_child_chunks)),
     )?
   }
+  Ok(())
+}
 
+#[plugin_hook(CompilationAdditionalTreeRuntimeRequirements for ChunkPrefetchPreloadPlugin)]
+async fn additional_tree_runtime_requirements(
+  &self,
+  compilation: &mut Compilation,
+  chunk_ukey: &ChunkUkey,
+  runtime_requirements: &mut RuntimeGlobals,
+) -> Result<()> {
   let chunk = compilation.chunk_by_ukey.expect_get(chunk_ukey);
   let chunk_filter = |_: &ChunkUkey, __: &Compilation| true;
   let mut chunk_map = chunk.get_child_ids_by_orders_map(false, compilation, &chunk_filter);
@@ -67,6 +84,10 @@ impl Plugin for ChunkPrefetchPreloadPlugin {
       .compilation_hooks
       .additional_tree_runtime_requirements
       .tap(additional_tree_runtime_requirements::new(self));
+    ctx
+      .compilation_hooks
+      .additional_chunk_runtime_requirements
+      .tap(additional_chunk_runtime_requirements::new(self));
     Ok(())
   }
 }

tests/rspack-test/configCases/web/prefetch-preload-runtime-chunk/chunk1.js

@@ -0,0 +1,5 @@
+export default function() {
+	import(/* webpackPrefetch: true, webpackChunkName: "chunk1-a" */ "./chunk1-a");
+	import(/* webpackPreload: true, webpackChunkName: "chunk1-b" */ "./chunk1-b");
+	import(/* webpackPrefetch: 10, webpackChunkName: "chunk1-c" */ "./chunk1-c");
+}

tests/rspack-test/configCases/web/prefetch-preload-runtime-chunk/chunk2.js

@@ -0,0 +1,4 @@
+export default function() {
+	import(/* webpackPrefetch: true, webpackChunkName: "chunk1-a" */ "./chunk1-a");
+	import(/* webpackPreload: true, webpackChunkName: "chunk1-b" */ "./chunk1-b");
+}

tests/rspack-test/configCases/web/prefetch-preload-runtime-chunk/index.js

@@ -0,0 +1,89 @@
+// This config need to be set on initial evaluation to be effective
+__webpack_nonce__ = "nonce";
+__webpack_public_path__ = "https://example.com/public/path/";
+
+it("should prefetch and preload child chunks on chunk load", () => {
+	let link, script;
+
+	expect(document.head._children).toHaveLength(1);
+
+	// Test prefetch from entry chunk
+	link = document.head._children[0];
+	expect(link._type).toBe("link");
+	expect(link.rel).toBe("prefetch");
+	expect(link.href).toBe("https://example.com/public/path/chunk1.js");
+
+	const promise = import(
+		/* webpackChunkName: "chunk1", webpackPrefetch: true */ "./chunk1"
+	);
+
+	expect(document.head._children).toHaveLength(3);
+
+	// Test normal script loading
+	script = document.head._children[1];
+	expect(script._type).toBe("script");
+	expect(script.src).toBe("https://example.com/public/path/chunk1.js");
+	expect(script.getAttribute("nonce")).toBe("nonce");
+	expect(script.crossOrigin).toBe("anonymous");
+	expect(script.onload).toBeTypeOf("function");
+
+	// Test preload of chunk1-b
+	link = document.head._children[2];
+	expect(link._type).toBe("link");
+	expect(link.rel).toBe("preload");
+	expect(link.as).toBe("script");
+	expect(link.href).toBe("https://example.com/public/path/chunk1-b.js");
+	expect(link.getAttribute("nonce")).toBe("nonce");
+	expect(link.crossOrigin).toBe("anonymous");
+
+	// Run the script
+	__non_webpack_require__("./chunk1.js");
+
+	script.onload();
+
+	return promise.then(() => {
+		expect(document.head._children).toHaveLength(4);
+
+		// Test prefetching for chunk1-c and chunk1-a in this order
+		link = document.head._children[2];
+		expect(link._type).toBe("link");
+		expect(link.rel).toBe("prefetch");
+		expect(link.href).toBe("https://example.com/public/path/chunk1-c.js");
+		expect(link.crossOrigin).toBe("anonymous");
+
+		link = document.head._children[3];
+		expect(link._type).toBe("link");
+		expect(link.rel).toBe("prefetch");
+		expect(link.href).toBe("https://example.com/public/path/chunk1-a.js");
+		expect(link.crossOrigin).toBe("anonymous");
+
+		const promise2 = import(
+			/* webpackChunkName: "chunk1", webpackPrefetch: true */ "./chunk1"
+		);
+
+		// Loading chunk1 again should not trigger prefetch/preload
+		expect(document.head._children).toHaveLength(4);
+
+		const promise3 = import(/* webpackChunkName: "chunk2" */ "./chunk2");
+
+		expect(document.head._children).toHaveLength(5);
+
+		// Test normal script loading
+		script = document.head._children[4];
+		expect(script._type).toBe("script");
+		expect(script.src).toBe("https://example.com/public/path/chunk2.js");
+		expect(script.getAttribute("nonce")).toBe("nonce");
+		expect(script.crossOrigin).toBe("anonymous");
+		expect(script.onload).toBeTypeOf("function");
+
+		// Run the script
+		__non_webpack_require__("./chunk2.js");
+
+		script.onload();
+
+		return promise3.then(() => {
+			// Loading chunk2 again should not trigger prefetch/preload as it's already prefetch/preloaded
+			expect(document.head._children).toHaveLength(4);
+		});
+	});
+});

tests/rspack-test/configCases/web/prefetch-preload-runtime-chunk/rspack.config.js

@@ -0,0 +1,32 @@
+const fs = require("fs");
+const path = require("path");
+
+/** @type {import("@rspack/core").Configuration} */
+module.exports = {
+	target: "web",
+	output: {
+		filename: "[name].js",
+		chunkFilename: "[name].js",
+		crossOriginLoading: "anonymous"
+	},
+	performance: {
+		hints: false
+	},
+	optimization: {
+		minimize: false,
+		runtimeChunk: {
+			name: entrypoint => `runtime~${entrypoint.name}`,
+		}
+	},
+	plugins: [{
+		apply(compiler) {
+			compiler.hooks.done.tap("DonePlugin", () => {
+				const output = compiler.options.output.path;
+				const runtime = fs.readFileSync(path.join(output, "runtime~main.js"), "utf-8");
+				expect(runtime).not.toContain("webpack/runtime/chunk_prefetch_startup");
+				const main = fs.readFileSync(path.join(output, "main.js"), "utf-8");
+				expect(main).toContain("webpack/runtime/chunk_prefetch_startup");
+			});
+		}
+	}]
+};

tests/rspack-test/configCases/web/prefetch-preload-runtime-chunk/test.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+  findBundle() {
+    return ["runtime~main.js", "main.js"];
+  }
+};