feat: Automatically use jar resource listener in a multimodule Maven project

flow-tests/pom.xml

@@ -46,7 +46,6 @@
         <vaadin.reuseDevServer>false</vaadin.reuseDevServer>
         <vaadin.devServerPort>0</vaadin.devServerPort>
         <vaadin.frontend.hotdeploy>true</vaadin.frontend.hotdeploy>
-        <vaadin.frontend.hotdeploy.dependencies></vaadin.frontend.hotdeploy.dependencies>
     </properties>
 
     <dependencies>
@@ -229,7 +228,6 @@
                             <!-- Allow test clients not on localhost to connect to Vite-->
                             <vaadin.devmode.vite.options>${vaadin.devmode.vite.options}</vaadin.devmode.vite.options>
                             <vaadin.frontend.hotdeploy>${vaadin.frontend.hotdeploy}</vaadin.frontend.hotdeploy>
-                            <vaadin.frontend.hotdeploy.dependencies>${vaadin.frontend.hotdeploy.dependencies}</vaadin.frontend.hotdeploy.dependencies>
                         </systemProperties>
                     </configuration>
                 </plugin>

flow-tests/test-live-reload-multimodule/ui/pom.xml

@@ -14,7 +14,6 @@
     <packaging>war</packaging>
     <properties>
         <maven.deploy.skip>true</maven.deploy.skip>
-        <vaadin.frontend.hotdeploy.dependencies>../library</vaadin.frontend.hotdeploy.dependencies>
     </properties>
 
     <dependencies>

vaadin-dev-server/src/main/java/com/vaadin/base/devserver/ExternalDependencyWatcher.java

@@ -30,6 +30,7 @@
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.w3c.dom.Document;
 
 import com.vaadin.flow.server.InitParameters;
 import com.vaadin.flow.server.VaadinContext;
@@ -44,16 +45,28 @@ public ExternalDependencyWatcher(VaadinContext context,
             File jarFrontendResourcesFolder) {
         ApplicationConfiguration config = ApplicationConfiguration.get(context);
 
-        String hotdeployDependencies = config.getStringProperty(
+        String hotdeployDependenciesProperty = config.getStringProperty(
                 InitParameters.FRONTEND_HOTDEPLOY_DEPENDENCIES, null);
 
         List<String> hotdeployDependencyFolders = new ArrayList<>();
-        if (hotdeployDependencies != null) {
-            for (String folder : hotdeployDependencies.split(",")) {
+        if (hotdeployDependenciesProperty != null) {
+            for (String folder : hotdeployDependenciesProperty.split(",")) {
                 if (!folder.isBlank()) {
                     hotdeployDependencyFolders.add(folder.trim());
                 }
             }
+        } else {
+            File parentPomFile = MavenUtils.getParentPomOfMultiModuleProject(
+                    new File(config.getProjectFolder(), "pom.xml"));
+            if (parentPomFile != null) {
+                Document parentPom = MavenUtils.parsePomFile(parentPomFile);
+                if (parentPom != null) {
+                    hotdeployDependencyFolders = MavenUtils
+                            .getModuleFolders(parentPom).stream()
+                            .map(folder -> ".." + File.separator + folder)
+                            .toList();
+                }
+            }
         }
 
         for (String hotdeployDependencyFolder : hotdeployDependencyFolders) {
@@ -62,7 +75,8 @@ public ExternalDependencyWatcher(VaadinContext context,
             Path metaInf = moduleFolder
                     .resolve(Path.of("src", "main", "resources", "META-INF"));
             if (!watchDependencyFolder(metaInf.toFile(),
-                    jarFrontendResourcesFolder)) {
+                    jarFrontendResourcesFolder)
+                    && hotdeployDependenciesProperty != null) {
                 getLogger().warn("No folders to watch were found in "
                         + metaInf.normalize().toAbsolutePath()
                         + ". This should be the META-INF folder that contains either frontend or resources/frontend");

vaadin-dev-server/src/main/java/com/vaadin/base/devserver/MavenUtils.java

@@ -4,14 +4,16 @@
 import javax.xml.parsers.DocumentBuilderFactory;
 
 import java.io.File;
+import java.io.IOException;
+import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Stream;
 import java.util.stream.Stream.Builder;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
-import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 
@@ -95,14 +97,18 @@ public static String getGroupId(Document pom) {
         String groupId = getFirstElementTextByName(pom.getDocumentElement(),
                 "groupId");
         if (groupId == null) {
-            groupId = findChild(pom.getDocumentElement(), "parent")
+            groupId = findParentTag(pom)
                     .map(parentNode -> getFirstElementTextByName(parentNode,
                             "groupId"))
                     .orElse(null);
         }
         return groupId;
     }
 
+    private static Optional<Node> findParentTag(Document pom) {
+        return findChild(pom.getDocumentElement(), "parent");
+    }
+
     /**
      * Finds the artifact id for the given pom file.
      *
@@ -115,6 +121,19 @@ public static String getArtifactId(Document pom) {
                 "artifactId");
     }
 
+    private static String getParentArtifactId(Document pom) {
+        return findParentTag(pom)
+                .flatMap(parentNode -> findChild(parentNode, "artifactId"))
+                .map(artifactIdNode -> artifactIdNode.getTextContent())
+                .orElse(null);
+    }
+
+    private static Optional<String> getParentRelativePath(Document pom) {
+        return findParentTag(pom)
+                .flatMap(parentNode -> findChild(parentNode, "relativePath"))
+                .map(artifactIdNode -> artifactIdNode.getTextContent());
+    }
+
     private static Optional<Node> findChild(Node node, String tagname) {
         return findChildren(node, tagname).findFirst();
     }
@@ -132,4 +151,79 @@ private static Stream<Node> findChildren(Node node, String tagname) {
         return builder.build();
     }
 
+    /**
+     * Gets the parent pom location for the given pom file, if the given pom
+     * file is part of a multi module project.
+     *
+     * @param pomFile
+     *            the pom file
+     * @return the location of the parent pom file or {@code null} if the given
+     *         pom file does not have a parent inside the same multi module
+     *         project
+     */
+    public static File getParentPomOfMultiModuleProject(File pomFile) {
+        Document pom = parsePomFile(pomFile);
+        if (pom == null) {
+            return null;
+        }
+        String parent = getParentArtifactId(pom);
+
+        File pomFolder = pomFile.getParentFile();
+        File parentPomFile = getParentRelativePath(pom)
+                .map(relativePath -> new File(pomFolder, relativePath))
+                .orElse(new File(pomFolder.getParentFile(), "pom.xml"));
+
+        Document parentFolderPom = parsePomFile(parentPomFile);
+        if (parentFolderPom == null) {
+            return null;
+        }
+        String parentFolderArtifactId = getArtifactId(parentFolderPom);
+
+        if (Objects.equals(parent, parentFolderArtifactId)) {
+            try {
+                return parentPomFile.getCanonicalFile();
+            } catch (IOException e) {
+                return parentPomFile;
+            }
+        }
+        return null;
+
+    }
+
+    /**
+     * Gets a list of the folders containing the sub modules for the given pom
+     * file.
+     *
+     * @param pom
+     *            the pom file containing sub modules
+     * @return a list of folders for the sub modules
+     */
+    public static List<String> getModuleFolders(Document pom) {
+        return findChild(pom.getDocumentElement(), "modules").stream()
+                .flatMap(node -> findChildren(node, "module"))
+                .map(moduleNode -> moduleNode.getTextContent())
+                .map(possiblyFilename -> removeAfter(possiblyFilename, "/"))
+                .toList();
+    }
+
+    /**
+     * Removes the part of the given string that comes after the (last) instance
+     * of the given delimiter.
+     *
+     * Returns the original string if it does not contain the delimiter.
+     *
+     * @param str
+     *            the string to parse
+     * @param delimiter
+     *            the delimiter to look for
+     * @return the modified string
+     */
+    private static String removeAfter(String str, String delimiter) {
+        int i = str.lastIndexOf(delimiter);
+        if (i != -1) {
+            return str.substring(0, i);
+        }
+        return str;
+    }
+
 }

vaadin-dev-server/src/test/java/com/vaadin/base/devserver/MavenUtilsTest.java

@@ -2,11 +2,12 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
+import java.net.URL;
+import java.nio.file.Path;
+import java.util.List;
 
-import org.apache.commons.io.FileUtils;
-import org.apache.commons.io.IOUtils;
 import org.junit.Assert;
+import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -17,8 +18,16 @@ public class MavenUtilsTest {
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
+    private File mavenFolder;
+
+    @Before
+    public void setupPoms() throws Exception {
+        URL mavenTestResourceDirectory = getClass().getResource("maven");
+        this.mavenFolder = Path.of(mavenTestResourceDirectory.toURI()).toFile();
+    }
+
     @Test
-    public void basicInformationForStandalonePom() throws IOException {
+    public void basicInformationForStandalonePom() throws Exception {
         File pomXml = getPomXml("pom-standalone.xml");
         Document parse = MavenUtils.parsePomFile(pomXml);
         Assert.assertEquals("this.group", MavenUtils.getGroupId(parse));
@@ -27,21 +36,56 @@ public void basicInformationForStandalonePom() throws IOException {
     }
 
     @Test
-    public void basicInformationForPomWithParent() throws IOException {
-        File pomXml = getPomXml("pom-with-parent.xml");
+    public void basicInformationForPomWithParent() throws Exception {
+        File pomXml = getPomXml("standard-multimodule/module1/pom.xml");
         Document parse = MavenUtils.parsePomFile(pomXml);
         Assert.assertEquals("this.group", MavenUtils.getGroupId(parse));
         Assert.assertEquals("this-the-artifact",
                 MavenUtils.getArtifactId(parse));
     }
 
+    @Test
+    public void detectsPomIsPartOfASimpleMultimoduleProject() throws Exception {
+        File parent = getPomXml("standard-multimodule/pom.xml");
+        Assert.assertEquals(parent, MavenUtils.getParentPomOfMultiModuleProject(
+                getPomXml("standard-multimodule/module1/pom.xml")));
+    }
+
+    @Test
+    public void detectsPomIsPartOfAComplexMultimoduleProject()
+            throws Exception {
+        File parent = getPomXml("complex-multimodule/pom-parent.xml");
+        File parentPomOfMultiModuleProject = MavenUtils
+                .getParentPomOfMultiModuleProject(getPomXml(
+                        "complex-multimodule/module1/pom-with-parent.xml"));
+        Assert.assertEquals(parent, parentPomOfMultiModuleProject);
+    }
+
+    @Test
+    public void findsModulesInSimpleMultiModulePom() throws Exception {
+        File pomXml = getPomXml("standard-multimodule/pom.xml");
+        Document pom = MavenUtils.parsePomFile(pomXml);
+        Assert.assertEquals(List.of("module1", "module2"),
+                MavenUtils.getModuleFolders(pom));
+    }
+
+    @Test
+    public void findsModulesInComplexMultiModulePom() throws Exception {
+        File pomXml = getPomXml("complex-multimodule/pom-parent.xml");
+        Document pom = MavenUtils.parsePomFile(pomXml);
+        Assert.assertEquals(List.of("module1", "module2"),
+                MavenUtils.getModuleFolders(pom));
+    }
+
+    @Test
+    public void findsNoModulesInStandalonePom() throws Exception {
+        File pomXml = getPomXml("pom-standalone.xml");
+        Document pom = MavenUtils.parsePomFile(pomXml);
+        Assert.assertEquals(List.of(), MavenUtils.getModuleFolders(pom));
+    }
+
     private File getPomXml(String filename) throws IOException {
-        File pomXml = temporaryFolder.newFile(filename);
-        FileUtils.write(pomXml,
-                IOUtils.toString(getClass().getResource("maven/" + filename),
-                        StandardCharsets.UTF_8),
-                StandardCharsets.UTF_8);
-        return pomXml;
+        return new File(mavenFolder, filename);
     }
 
 }

vaadin-dev-server/src/test/resources/com/vaadin/base/devserver/maven/pom-with-parent.xml → vaadin-dev-server/src/test/resources/com/vaadin/base/devserver/maven/complex-multimodule/module1/pom-with-parent.xml

@@ -4,8 +4,10 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <parent>
+        <artifactId>parent-artifact</artifactId>
         <groupId>this.group</groupId>
         <version>1.7.2-SNAPSHOT</version>
+        <relativePath>../pom-parent.xml</relativePath>
     </parent>
     <artifactId>this-the-artifact</artifactId>
     <name>Something something</name>

vaadin-dev-server/src/test/resources/com/vaadin/base/devserver/maven/complex-multimodule/module2/pom.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <artifactId>parent-artifact</artifactId>
+        <groupId>this.group</groupId>
+        <version>1.7.2-SNAPSHOT</version>
+        <relativePath>../pom-parent.xml</relativePath>
+    </parent>
+    <artifactId>another-artifact</artifactId>
+    <name>Something something</name>
+
+    <build>
+    </build>
+
+</project>

vaadin-dev-server/src/test/resources/com/vaadin/base/devserver/maven/complex-multimodule/pom-parent.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>this.group</groupId>
+    <artifactId>parent-artifact</artifactId>
+    <version>1.7.2-SNAPSHOT</version>
+    <name>Something something parent</name>
+    <packaging>pom</packaging>
+    <modules>
+        <module>module1/pom-with-parent.xml</module>
+        <module>module2</module>
+    </modules>
+
+</project>

vaadin-dev-server/src/test/resources/com/vaadin/base/devserver/maven/pom-standalone.xml

@@ -8,7 +8,4 @@
     <version>1.7.2-SNAPSHOT</version>
     <name>Something something</name>
 
-    <build>
-    </build>
-
 </project>

vaadin-dev-server/src/test/resources/com/vaadin/base/devserver/maven/standard-multimodule/module1/pom.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <artifactId>parent-artifact</artifactId>
+        <groupId>this.group</groupId>
+        <version>1.7.2-SNAPSHOT</version>
+    </parent>
+    <artifactId>this-the-artifact</artifactId>
+    <name>Something something</name>
+
+    <build>
+    </build>
+
+</project>