Fix for ProjectMerger.mergeMavenPlugins Xml Declarations Issue

src/main/java/org/springframework/cli/util/ConversionUtils.java

@@ -18,6 +18,8 @@
 
 import java.io.StringWriter;
 import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
 
 import javax.xml.bind.JAXB;
 
@@ -33,17 +35,33 @@ private ConversionUtils() {
 
 	}
 
+	/**
+	 * Converts Xpp3Dom to a String without any xml declaration
+	 * @param dom the Xpp3Dom to convert
+	 * @return String without any Xml Declarations
+	 */
 	public static String fromDomToString(Xpp3Dom dom) {
 		String element = dom.toString();
-		return element;
+        return element.lines().filter(l -> !l.contains("<?xml")).collect(Collectors.joining("\n"));
 	}
 
+	/**
+	 * Formats a list of Maven Dependencies as a String without the xml declaration
+	 * @param dependencies the list of Maven Dependencies to convert
+	 * @return String without any Xml Declarations or optional and type elements if they contain default values
+	 */
 	public static String fromDependencyListToString(List<Dependency> dependencies) {
 		StringWriter sw = new StringWriter();
+
 		Dependencies deps = new Dependencies(dependencies);
 		JAXB.marshal(deps, sw);
 		String xmlString = sw.toString();
-		return xmlString;
+		// filter out lines containing xml declarations and default elements like:
+		// <optional>false</optional> and <type>jar</type>
+		return xmlString.lines().filter(l -> !l.contains("<?xml") &&
+				!l.contains("<optional>false</optional>") &&
+				!l.contains("<type>jar</type>"))
+				.collect(Collectors.joining("\n"));
 	}
 
 	/*
@@ -52,18 +70,18 @@ public static String fromDependencyListToString(List<Dependency> dependencies) {
 	 */
 	public static class Dependencies {
 
-		private List<Dependency> dependencies;
+		private List<Dependency> dependency;
 
 		public Dependencies(List<Dependency> dependencies) {
-			this.dependencies = dependencies;
+			this.dependency = dependencies;
 		}
 
-		public List<Dependency> getDependencies() {
-			return dependencies;
+		public List<Dependency> getDependency() {
+			return dependency;
 		}
 
-		public void setDependencies(List<Dependency> dependencies) {
-			this.dependencies = dependencies;
+		public void setDependency(List<Dependency> dependencies) {
+			this.dependency = dependencies;
 		}
 
 	}

src/test/java/org/springframework/cli/merger/MavenModificationTests.java

@@ -78,7 +78,11 @@ void addPluginDependency(@TempDir Path tempDir) throws Exception {
 				pomReader.readPom(pomToMerge.toFile()), paths, mavenParser);
 
 		Model mergedModel = pomReader.readPom(mergedPomPath.toFile());
+		assertThat(mergedModel.getBuild().getPlugins()).hasSize(3);
+		List<String> mergedPluginIds = new ArrayList<>();
 		for (Plugin plugin : mergedModel.getBuild().getPlugins()) {
+
+			mergedPluginIds.add(plugin.getArtifactId());
 			if (plugin.getGroupId().equals("org.apache.maven.plugins")
 					&& plugin.getArtifactId().equals("maven-deploy-plugin")) {
 				assertThat(ConversionUtils.fromDomToString((Xpp3Dom) plugin.getConfiguration()))
@@ -98,6 +102,8 @@ else if (plugin.getGroupId().equals("org.springframework.boot")
 				assertThat(dep.getArtifactId()).isEqualTo("spring-boot-thin-layout");
 			}
 		}
+		assertThat(mergedPluginIds).containsExactlyInAnyOrder("maven-deploy-plugin", "maven-shade-plugin",
+				"spring-boot-maven-plugin");
 	}
 
 	@Test

src/test/java/org/springframework/cli/util/ConversionUtilsTest.java

@@ -0,0 +1,87 @@
+package org.springframework.cli.util;
+
+import org.apache.maven.model.Dependency;
+import org.codehaus.plexus.util.xml.Xpp3Dom;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+//@Disabled("This is a WIP Test")
+class ConversionUtilsTest {
+
+
+
+    @DisplayName("Characterization Test to validate how this current works, note the xml declaration AND the duplicate dependencies element")
+    @Disabled("This test exists to show what was actually coming out of ConversionUtil")
+    @Test
+    void existingFromDependencyListToString() {
+        List<Dependency> dependencies = new ArrayList<>();
+        Dependency dependency = new Dependency();
+        dependency.setGroupId("org.springframework");
+        dependency.setArtifactId("spring-core");
+        dependency.setVersion("5.2.0.RELEASE");
+        dependencies.add(dependency);
+        String result = ConversionUtils.fromDependencyListToString(dependencies);
+        assertThat(result.replaceAll("\\s",""))
+                .isEqualTo("<?xmlversion=\"1.0\"encoding=\"UTF-8\"standalone=\"yes\"?>" +
+                        "<dependencies>" +
+                        "<dependencies>" +
+                        "<artifactId>spring-core</artifactId>" +
+                        "<groupId>org.springframework</groupId>" +
+                        "<optional>false</optional>" +
+                        "<version>5.2.0.RELEASE</version>" +
+                        "</dependencies>" +
+                        "</dependencies>");
+
+    }
+
+    @DisplayName("After ConversionUtils is corrected, this test should pass")
+    @Test
+    void validateFromDependencyListToString() {
+        List<Dependency> dependencies = new ArrayList<>();
+        Dependency dependency = new Dependency();
+        dependency.setGroupId("org.springframework");
+        dependency.setArtifactId("spring-core");
+        dependency.setVersion("5.2.0.RELEASE");
+        dependencies.add(dependency);
+        String result = ConversionUtils.fromDependencyListToString(dependencies);
+        assertThat(result.replaceAll("\\s",""))
+                .isEqualTo("<dependencies>" +
+                        "<dependency>" +
+                        "<artifactId>spring-core</artifactId>" +
+                        "<groupId>org.springframework</groupId>" +
+                        "<version>5.2.0.RELEASE</version>" +
+                        "</dependency>" +
+                        "</dependencies>");
+
+    }
+
+
+    @DisplayName("fromDomToString removes XML declaration")
+    @Test
+    void fromDomToStringRemovesXmlDeclaration() {
+        Xpp3Dom dom = new Xpp3Dom("root");
+        Xpp3Dom child = new Xpp3Dom("child");
+        child.setValue("value");
+        dom.addChild(child);
+        String result = ConversionUtils.fromDomToString(dom);
+        assertThat(result).doesNotContain("<?xml").contains("<root>").contains("</root>").contains("<child>value</child>");
+    }
+
+    @DisplayName("fromDomToString handles empty Xpp3Dom")
+    @Test
+    void fromDomToStringHandlesEmptyXpp3Dom() {
+        Xpp3Dom dom = new Xpp3Dom("root");
+        String result = ConversionUtils.fromDomToString(dom);
+        assertThat(result).isEqualTo("<root/>");
+    }
+
+
+
+
+}