fix: increase parallelism when using `importModule` on the execution stage

lib/dependencies/LoaderPlugin.js

@@ -197,6 +197,7 @@ class LoaderPlugin {
 								if (!referencedModule) {
 									return callback(new Error("Cannot load the module"));
 								}
+								compilation.buildQueue.increaseParallelism();
 								compilation.executeModule(
 									referencedModule,
 									{
@@ -206,6 +207,7 @@ class LoaderPlugin {
 										}
 									},
 									(err, result) => {
+										compilation.buildQueue.decreaseParallelism();
 										if (err) return callback(err);
 										const {
 											fileDependencies,

test/configCases/performance/many-async-imports/test.filter.js

@@ -1,3 +0,0 @@
-module.exports = function (config) {
-	return !/^v(4|6)/.test(process.version);
-};

test/configCases/performance/many-exports/test.filter.js

@@ -1,3 +0,0 @@
-module.exports = function (config) {
-	return !/^v(4|6)/.test(process.version);
-};

test/configCases/race-conditions/import-module/index.js

@@ -0,0 +1,7 @@
+import * as styles from './style.module.css';
+import * as styles1 from './module.js';
+
+it("should not deadlock when using importModule", () => {
+	expect(styles.someBottom).toBe("8px");
+	expect(styles1.someBottom).toBe("8px");
+});

test/configCases/race-conditions/import-module/inner.module.css

@@ -0,0 +1 @@
+@value someBottom from "./vars.module.css";

test/configCases/race-conditions/import-module/loader.js

@@ -0,0 +1,21 @@
+/** @type {import("../../../../").LoaderDefinition} */
+module.exports.pitch = function (request) {
+	const callback = this.async();
+	let finished = false;
+
+	this.importModule(
+		`${this.resourcePath}.webpack[javascript/auto]!=!!!${request}`,
+		{},
+		(err, result) => {
+			if (err) return callback(err);
+			if (finished) return;
+			finished = true;
+			callback(null, `module.exports = ${JSON.stringify(result)};`);
+		}
+	);
+	setTimeout(() => {
+		if (finished) return;
+		finished = true;
+		callback(new Error("importModule is hanging"));
+	}, 2000);
+};

test/configCases/race-conditions/import-module/module.js

@@ -0,0 +1 @@
+export * from './style1.module.css'

test/configCases/race-conditions/import-module/style.module.css

@@ -0,0 +1,5 @@
+@value someBottom from "./inner.module.css";
+
+.cold {
+	bottom: someBottom;
+}

test/configCases/race-conditions/import-module/style1.module.css

@@ -0,0 +1,5 @@
+@value someBottom from "./inner.module.css";
+
+.cold {
+	bottom: someBottom;
+}

test/configCases/race-conditions/import-module/test.filter.js

@@ -0,0 +1,5 @@
+module.exports = function (config) {
+	const [major] = process.versions.node.split(".").map(Number);
+
+	return major >= 18;
+};

test/configCases/race-conditions/import-module/vars.module.css

@@ -0,0 +1,2 @@
+@value someBottom: 8px;
+@value someBottom1: 8px;

test/configCases/race-conditions/import-module/webpack.config.js

@@ -0,0 +1,13 @@
+/** @type {import("../../../../").Configuration} */
+module.exports = {
+	parallelism: 1,
+	mode: "development",
+	module: {
+		rules: [
+			{
+				test: /\.css$/i,
+				use: [require.resolve("./loader"), "css-loader"]
+			}
+		]
+	}
+};