fix: do not crash when a referenced chunk is not a runtime chunk (#20461)

alexander-akait · web-flow · commit 2a0c16eca4ee · 2026-02-16T18:41:22.000+03:00
diff --git a/.changeset/gold-pans-cross.md b/.changeset/gold-pans-cross.md
@@ -0,0 +1,5 @@
+---
+"webpack": patch
+---
+
+Do not crash when a referenced chunk is not a runtime chunk.
diff --git a/lib/Compilation.js b/lib/Compilation.js
@@ -4531,12 +4531,14 @@ Or do you want to use the entrypoints '${name}' and '${runtime}' independently o
 					(e) => e.chunks[e.chunks.length - 1]
 				)
 			)) {
-				const otherInfo =
-					/** @type {RuntimeChunkInfo} */
-					(runtimeChunksMap.get(other));
-				otherInfo.referencedBy.push(info);
-				info.remaining++;
-				remaining++;
+				const otherInfo = runtimeChunksMap.get(other);
+				// other may be a non-runtime chunk (e.g. worker chunk)
+				// when you have a worker chunk in your app.js (new Worker(...)) and as a separate entry point
+				if (otherInfo) {
+					otherInfo.referencedBy.push(info);
+					info.remaining++;
+					remaining++;
+				}
 			}
 		}
 		/** @type {Chunk[]} */
diff --git a/test/configCases/worker/issue-17105/app.js b/test/configCases/worker/issue-17105/app.js
@@ -0,0 +1,15 @@
+import { Worker } from "worker_threads";
+
+it("should build and run when worker is an entry and using via `new Worker(...)`", async () => {
+	const worker = new Worker(
+		/* webpackChunkName: "my-worker" */ new URL("./worker.js", import.meta.url)
+	);
+	worker.postMessage({ data: "ping" });
+	const result = await new Promise(resolve => {
+		worker.on("message", event => {
+			resolve(event.data);
+		});
+	});
+	expect(result).toBe("pong");
+	await worker.terminate();
+});
diff --git a/test/configCases/worker/issue-17105/test.config.js b/test/configCases/worker/issue-17105/test.config.js
@@ -0,0 +1,7 @@
+"use strict";
+
+module.exports = {
+	findBundle(i, options) {
+		return ["app.js"];
+	}
+};
diff --git a/test/configCases/worker/issue-17105/test.filter.js b/test/configCases/worker/issue-17105/test.filter.js
@@ -0,0 +1,5 @@
+"use strict";
+
+const supportsWorker = require("../../../helpers/supportsWorker");
+
+module.exports = () => supportsWorker();
diff --git a/test/configCases/worker/issue-17105/webpack.config.js b/test/configCases/worker/issue-17105/webpack.config.js
@@ -0,0 +1,38 @@
+"use strict";
+
+/** @typedef {import("../../../../").Module} Module */
+
+/** @type {import("../../../../").Configuration} */
+module.exports = {
+	target: "node",
+	entry: {
+		app: "./app.js",
+		"my-worker": "./worker.js"
+	},
+	output: {
+		filename: "[name].js",
+		environment: {
+			nodePrefixForCoreModules: false
+		}
+	},
+	optimization: {
+		runtimeChunk: { name: "runtime" },
+		splitChunks: {
+			cacheGroups: {
+				vendor: {
+					/**
+					 * @param {Module} mod module
+					 * @returns {string | boolean | null} result
+					 */
+					test(mod) {
+						return mod.context && mod.context.includes("node_modules");
+					},
+					chunks: "all",
+					name: "vendor",
+					priority: 10,
+					enforce: true
+				}
+			}
+		}
+	}
+};
diff --git a/test/configCases/worker/issue-17105/worker.js b/test/configCases/worker/issue-17105/worker.js
@@ -0,0 +1,7 @@
+import { parentPort } from "worker_threads";
+
+if (parentPort) {
+	parentPort.on("message", event => {
+		parentPort.postMessage(event.data === "ping" ? { data: "pong" } : { data: "unexpected" });
+	});
+}

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +"webpack": patch
 +---
++
 +Do not crash when a referenced chunk is not a runtime chunk.