fix: bump npm infrastructure dependencies and make sure changing serve.js content is applied

lib/build.gradle

@@ -76,6 +76,7 @@ dependencies {
 	testCommonImplementation "org.junit.jupiter:junit-jupiter:$VER_JUNIT"
 	testCommonImplementation "org.assertj:assertj-core:$VER_ASSERTJ"
 	testCommonImplementation "com.diffplug.durian:durian-testlib:$VER_DURIAN"
+	testCommonImplementation projects.testlib
 	testCommonRuntimeOnly "org.junit.platform:junit-platform-launcher"
 
 	// GLUE CODE (alphabetic order please)

lib/src/main/java/com/diffplug/spotless/npm/NodeServerLayout.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2023 DiffPlug
+ * Copyright 2020-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -37,16 +37,16 @@ class NodeServerLayout {
 	private final File serveJsFile;
 	private final File npmrcFile;
 
-	NodeServerLayout(File buildDir, String packageJsonContent) {
-		this.nodeModulesDir = new File(buildDir, nodeModulesDirName(packageJsonContent));
+	NodeServerLayout(File buildDir, String packageJsonContent, String serveJsContent) {
+		this.nodeModulesDir = new File(buildDir, nodeModulesDirName(packageJsonContent, serveJsContent));
 		this.packageJsonFile = new File(nodeModulesDir, "package.json");
 		this.packageLockJsonFile = new File(nodeModulesDir, "package-lock.json");
 		this.serveJsFile = new File(nodeModulesDir, "serve.js");
 		this.npmrcFile = new File(nodeModulesDir, ".npmrc");
 	}
 
-	private static String nodeModulesDirName(String packageJsonContent) {
-		String md5Hash = NpmResourceHelper.md5(packageJsonContent);
+	private static String nodeModulesDirName(String packageJsonContent, String serveJsContent) {
+		String md5Hash = NpmResourceHelper.md5(packageJsonContent, serveJsContent);
 		Matcher matcher = PACKAGE_JSON_NAME_PATTERN.matcher(packageJsonContent);
 		if (!matcher.find()) {
 			throw new IllegalArgumentException("package.json must contain a name property");

lib/src/main/java/com/diffplug/spotless/npm/NpmFormatterStepStateBase.java

@@ -71,7 +71,7 @@ public static class Runtime {
 
 		Runtime(NpmFormatterStepStateBase parent) {
 			this.parent = parent;
-			this.nodeServerLayout = new NodeServerLayout(parent.locations.buildDir(), parent.npmConfig.getPackageJsonContent());
+			this.nodeServerLayout = new NodeServerLayout(parent.locations.buildDir(), parent.npmConfig.getPackageJsonContent(), parent.npmConfig.getServeScriptContent());
 			this.nodeServeApp = new NodeServeApp(nodeServerLayout, parent.npmConfig, parent.locations);
 		}
 

lib/src/main/java/com/diffplug/spotless/npm/NpmResourceHelper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2023 DiffPlug
+ * Copyright 2016-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@
 import java.util.Objects;
 import java.util.concurrent.TimeoutException;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import com.diffplug.spotless.ThrowingEx;
 
@@ -140,9 +141,15 @@ static String md5(File file) {
 		return md5(readUtf8StringFromFile(file));
 	}
 
-	static String md5(String fileContent) {
+	static String md5(String fileContent, String... additionalFileContents) {
+		Objects.requireNonNull(fileContent, "fileContent must not be null");
+		Stream<String> additionalFilecontentStream = Stream.concat(
+				Stream.of(fileContent),
+				Stream.of(additionalFileContents));
 		MessageDigest md = ThrowingEx.get(() -> MessageDigest.getInstance("MD5"));
-		md.update(fileContent.getBytes(StandardCharsets.UTF_8));
+		String stringToHash = additionalFilecontentStream.collect(Collectors.joining("@@@"));
+		md.update(stringToHash.getBytes(StandardCharsets.UTF_8));
+
 		byte[] digest = md.digest();
 		// convert byte array digest to hex string
 		StringBuilder sb = new StringBuilder();

lib/src/main/resources/com/diffplug/spotless/npm/common-serve.js

@@ -1,6 +1,6 @@
 // this file will be glued to the top of the specific xy-serve.js file
 const debug_serve = false; // set to true for debug log output in node process
-const GracefulShutdownManager = require("@moebius/http-graceful-shutdown").GracefulShutdownManager;
+const gracefulShutdown = require("http-graceful-shutdown");
 const express = require("express");
 const app = express();
 
@@ -48,12 +48,14 @@ var listener = app.listen(0, "127.0.0.1", () => {
 		}
 	});
 });
-const shutdownManager = new GracefulShutdownManager(listener);
+const shutdown = gracefulShutdown(listener, {
+	forceExit: false, // let the event loop clear
+	finally: () => debugLog("graceful shutdown finished."),
+});
 
 app.post("/shutdown", (req, res) => {
 	res.status(200).send("Shutting down");
-	setTimeout(function () {
-		shutdownManager.terminate(() => debugLog("graceful shutdown finished."));
+	setTimeout(async () => {
+		await shutdown()
 	}, 200);
 });
-

lib/src/main/resources/com/diffplug/spotless/npm/eslint-package.json

@@ -1,6 +1,6 @@
 {
 	"name": "spotless-eslint",
-	"version": "2.0.0",
+	"version": "4.0.0",
 	"description": "Spotless formatter step for running eslint as a rest service.",
 	"repository": "https://github.com/diffplug/spotless",
 	"license": "Apache-2.0",
@@ -9,11 +9,11 @@
 	},
 	"devDependencies": {
 ${devDependencies},
-		"express": "4.18.2",
-		"@moebius/http-graceful-shutdown": "1.1.0"
+		"express": "5.1.0",
+		"http-graceful-shutdown": "3.1.14"
 	},
 	"dependencies": {},
 	"engines": {
-		"node": ">=6"
+		"node": ">= 18"
 	}
 }

lib/src/main/resources/com/diffplug/spotless/npm/prettier-package.json

@@ -1,6 +1,6 @@
 {
 	"name": "spotless-prettier",
-	"version": "2.0.0",
+	"version": "4.0.0",
 	"description": "Spotless formatter step for running prettier as a rest service.",
 	"repository": "https://github.com/diffplug/spotless",
 	"license": "Apache-2.0",
@@ -9,11 +9,11 @@
 	},
 	"devDependencies": {
 ${devDependencies},
-		"express": "4.18.2",
-		"@moebius/http-graceful-shutdown": "1.1.0"
+		"express": "5.1.0",
+		"http-graceful-shutdown": "3.1.14"
 	},
 	"dependencies": {},
 	"engines": {
-		"node": ">=6"
+		"node": ">= 18"
 	}
 }

lib/src/main/resources/com/diffplug/spotless/npm/tsfmt-package.json

@@ -1,6 +1,6 @@
 {
 	"name": "spotless-tsfmt",
-	"version": "2.0.0",
+	"version": "4.0.0",
 	"description": "Spotless formatter step for running tsfmt as a rest service.",
 	"repository": "https://github.com/diffplug/spotless",
 	"license": "Apache-2.0",
@@ -9,11 +9,11 @@
 	},
 	"devDependencies": {
 ${devDependencies},
-		"express": "4.18.2",
-		"@moebius/http-graceful-shutdown": "1.1.0"
+		"express": "5.1.0",
+		"http-graceful-shutdown": "3.1.14"
 	},
 	"dependencies": {},
 	"engines": {
-		"node": ">= 4.2.0"
+		"node": ">= 18"
 	}
 }

lib/src/main/resources/com/diffplug/spotless/npm/tsfmt-serve.js

@@ -19,7 +19,7 @@ app.post("/tsfmt/format", (req, res) => {
         */
 		// result contains 'message' (String), 'error' (boolean), 'dest' (String) => formatted
 		if (resultMap.error !== undefined && resultMap.error) {
-			res.status(400).send(resultmap.message);
+			res.status(400).send(resultMap.message);
 			return;
 		}
 		res.set("Content-Type", "text/plain");

lib/src/test/java/com/diffplug/spotless/npm/NodeServerLayoutTest.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2025 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.spotless.npm;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import com.diffplug.spotless.ResourceHarness;
+
+class NodeServerLayoutTest extends ResourceHarness {
+
+	@Test
+	void itCalculatesSameNodeModulesDirForSameContent() throws IOException {
+		File testDir = newFolder("build");
+		String packageJsonContent = prettierPackageJson(Collections.emptyMap());
+		String serveJsContent = "fun main() { console.log('Hello, world!'); }";
+		NodeServerLayout layout1 = new NodeServerLayout(testDir, packageJsonContent, serveJsContent);
+		NodeServerLayout layout2 = new NodeServerLayout(testDir, packageJsonContent, serveJsContent);
+
+		assertThat(layout1.nodeModulesDir()).isEqualTo(layout2.nodeModulesDir());
+	}
+
+	@Test
+	void itCalculatesDifferentNodeModulesDirForDifferentPackageJson() throws IOException {
+		File testDir = newFolder("build");
+		String packageJsonContent1 = prettierPackageJson(Collections.singletonMap("prettier-plugin-xy", "^2.0.0"));
+		String packageJsonContent2 = prettierPackageJson(Collections.singletonMap("prettier-plugin-xy", "^2.1.0"));
+		String serveJsContent = "fun main() { console.log('Hello, world!'); }";
+
+		NodeServerLayout layout1 = new NodeServerLayout(testDir, packageJsonContent1, serveJsContent);
+		NodeServerLayout layout2 = new NodeServerLayout(testDir, packageJsonContent2, serveJsContent);
+
+		assertThat(layout1.nodeModulesDir()).isNotEqualTo(layout2.nodeModulesDir());
+	}
+
+	@Test
+	void itCalculatesDifferentNodeModulesDirForDifferentServeJs() throws IOException {
+		File testDir = newFolder("build");
+		String packageJsonContent = prettierPackageJson(Collections.emptyMap());
+		String serveJsContent1 = "fun main() { console.log('Hello, world!'); }";
+		String serveJsContent2 = "fun main() { console.log('Goodbye, world!'); }";
+
+		NodeServerLayout layout1 = new NodeServerLayout(testDir, packageJsonContent, serveJsContent1);
+		NodeServerLayout layout2 = new NodeServerLayout(testDir, packageJsonContent, serveJsContent2);
+
+		assertThat(layout1.nodeModulesDir()).isNotEqualTo(layout2.nodeModulesDir());
+	}
+
+	static String prettierPackageJson(Map<String, String> dependencies) {
+		String templateContent = NpmResourceHelper.readUtf8StringFromClasspath(NodeServerLayoutTest.class, "/com/diffplug/spotless/npm/prettier-package.json");
+		String dependenciesList = dependencies.entrySet().stream()
+				.map(entry -> String.format("\"%s\": \"%s\"", entry.getKey(), entry.getValue()))
+				.reduce((a, b) -> a + ",\n  " + b)
+				.orElse("");
+
+		return templateContent.replace("${devDependencies}", dependenciesList);
+	}
+}

lib/src/test/java/com/diffplug/spotless/npm/NpmResourceHelperTest.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2025 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.spotless.npm;
+
+import static com.diffplug.selfie.Selfie.expectSelfie;
+
+import org.junit.jupiter.api.Test;
+
+class NpmResourceHelperTest {
+
+	@Test
+	void itCalculatesMd5ForSingleString() {
+		String input = "Hello, World!";
+
+		expectSelfie(NpmResourceHelper.md5(input)).toBe("65a8e27d8879283831b664bd8b7f0ad4");
+	}
+
+	@Test
+	void itCalculatesMd5ForMultipleStrings() {
+		String input1 = "Hello, World!";
+		String input2 = "Hello, Spencer!";
+
+		expectSelfie(NpmResourceHelper.md5(input1, input2)).toBe("371ba0fbf3d73b33e71b4af8dc6afe00");
+	}
+}