fix: hotUpdate chunk modified with new runtime should have correct runtime

lib/HotModuleReplacementPlugin.js

@@ -686,7 +686,9 @@ class HotModuleReplacementPlugin {
 								if (backCompat)
 									ChunkGraph.setChunkGraphForChunk(hotUpdateChunk, chunkGraph);
 								hotUpdateChunk.id = chunkId;
-								hotUpdateChunk.runtime = newRuntime;
+								hotUpdateChunk.runtime = currentChunk
+									? currentChunk.runtime
+									: newRuntime;
 								if (currentChunk) {
 									for (const group of currentChunk.groupsIterable)
 										hotUpdateChunk.addGroup(group);

test/hotCases/runtime/add-runtime/index.js

@@ -0,0 +1,13 @@
+let value = require("./module.js");
+import {a} from "./lib/a.js";
+
+it("should compile", (done) => {
+	expect(value).toBe(1);
+	expect(a).toBe(1);
+	module.hot.accept("./module.js", () => {
+		value = require("./module");
+		expect(value).toBe(2);
+		done();
+	});
+	NEXT(require("../../update")(done));
+});

test/hotCases/runtime/add-runtime/lib/a.js

@@ -0,0 +1 @@
+export const a = 1

test/hotCases/runtime/add-runtime/lib/b.js

@@ -0,0 +1 @@
+export const b = 1

test/hotCases/runtime/add-runtime/lib/package.json

@@ -0,0 +1,3 @@
+{
+  "sideEffects": true
+}

test/hotCases/runtime/add-runtime/module.js

@@ -0,0 +1,4 @@
+module.exports = 1;
+---
+new Worker(new URL('./worker.js', import.meta.url))
+module.exports = 2;

test/hotCases/runtime/add-runtime/test.filter.js

@@ -0,0 +1,8 @@
+var supportsWorker = require("../../../helpers/supportsWorker");
+
+module.exports = function (config) {
+	if (config.target !== "web") {
+		return false;
+	}
+	return supportsWorker();
+};

test/hotCases/runtime/add-runtime/webpack.config.js

@@ -0,0 +1,17 @@
+module.exports = {
+	optimization: {
+		usedExports: true,
+		// make 'lib' chunk runtime to be worker + entry
+		splitChunks: {
+			minSize: 0,
+			chunks: "all",
+			cacheGroups: {
+				lib: {
+					test: /[/\\]lib[/\\](a|b|index).js$/,
+					name: "lib",
+					filename: "bundle-lib.js"
+				}
+			}
+		}
+	}
+};

test/hotCases/runtime/add-runtime/worker.js

@@ -0,0 +1,2 @@
+import {b} from "./lib/b.js";
+b;