Polish "Add support for Maven extensions"

See gh-1290

initializr-generator/src/main/java/io/spring/initializr/generator/buildsystem/maven/MavenBuild.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,7 +38,7 @@ public class MavenBuild extends Build {
 
 	private final MavenPluginContainer plugins = new MavenPluginContainer();
 
-	private final MavenExtensionsContainer extensions = new MavenExtensionsContainer();
+	private final MavenExtensionContainer extensions = new MavenExtensionContainer();
 
 	private final MavenDistributionManagement.Builder distributionManagement = new MavenDistributionManagement.Builder();
 
@@ -109,11 +109,11 @@ public class MavenBuild extends Build {
 	}
 
 	/**
-	 * Return the {@linkplain MavenExtensionsContainer extensions container} to use to
+	 * Return the {@linkplain MavenExtensionContainer extension container} to use to
 	 * configure extensions.
-	 * @return the {@link MavenExtensionsContainer}
+	 * @return the {@link MavenExtensionContainer}
 	 */
-	public MavenExtensionsContainer extensions() {
+	public MavenExtensionContainer extensions() {
 		return this.extensions;
 	}
 

initializr-generator/src/main/java/io/spring/initializr/generator/buildsystem/maven/MavenExtension.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,9 +17,10 @@
 package io.spring.initializr.generator.buildsystem.maven;
 
 /**
- * An extension entry in a @{@link MavenBuild}.
+ * A build extension in a @{@link MavenBuild}.
  *
  * @author Niklas Herder
+ * @author Stephane Nicoll
  */
 public class MavenExtension {
 
@@ -27,7 +28,7 @@ public class MavenExtension {
 
 	private final String artifactId;
 
-	private String version;
+	private final String version;
 
 	protected MavenExtension(Builder builder) {
 		this.groupId = builder.groupId;
@@ -35,14 +36,26 @@ public class MavenExtension {
 		this.version = builder.version;
 	}
 
+	/**
+	 * Return the group ID of the extension.
+	 * @return the group id
+	 */
 	public String getGroupId() {
 		return this.groupId;
 	}
 
+	/**
+	 * Return the artifact ID of the extension.
+	 * @return the artifact id
+	 */
 	public String getArtifactId() {
 		return this.artifactId;
 	}
 
+	/**
+	 * Return the version of the extension.
+	 * @return the artifact id
+	 */
 	public String getVersion() {
 		return this.version;
 	}
@@ -60,11 +73,20 @@ public class MavenExtension {
 			this.artifactId = artifactId;
 		}
 
+		/**
+		 * Set the version of the extension.
+		 * @param version the version of the extension
+		 * @return this for method chaining
+		 */
 		public Builder version(String version) {
 			this.version = version;
 			return this;
 		}
 
+		/**
+		 * Build a {@link MavenExtension} with the current state of this builder.
+		 * @return a {@link MavenExtension}
+		 */
 		public MavenExtension build() {
 			return new MavenExtension(this);
 		}

initializr-generator/src/main/java/io/spring/initializr/generator/buildsystem/maven/MavenExtensionContainer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,13 @@ import java.util.Map;
 import java.util.function.Consumer;
 import java.util.stream.Stream;
 
-public class MavenExtensionsContainer {
+/**
+ * A container for {@link MavenExtension maven extensions}.
+ *
+ * @author Niklas Herder
+ * @author Stephane Nicoll
+ */
+public class MavenExtensionContainer {
 
 	private final Map<String, MavenExtension.Builder> extensions = new LinkedHashMap<>();
 
@@ -54,14 +60,16 @@ public class MavenExtensionsContainer {
 	}
 
 	/**
-	 * Add a {@link MavenExtension} with the specified {@code groupId} and
+	 * Add a {@link MavenExtension} with the specified {@code groupId},
-	 * {@code artifactId}. Does nothing if the extension has already been added.
+	 * {@code artifactId}, and {@code version}. If the extension has already been added,
+	 * only update the version if necessary.
 	 * @param groupId the groupId of the extension
 	 * @param artifactId the artifactId of the extension
+	 * @param version the version of the extension
 	 * @see #add(String, String, Consumer)
 	 */
-	public void add(String groupId, String artifactId) {
+	public void add(String groupId, String artifactId, String version) {
-		addExtension(groupId, artifactId);
+		add(groupId, artifactId, (extension) -> extension.version(version));
 	}
 
 	/**

initializr-generator/src/test/java/io/spring/initializr/generator/buildsystem/maven/MavenBuildWriterTests.java

@@ -700,6 +700,23 @@ class MavenBuildWriterTests {
 		});
 	}
 
+	@Test
+	void pomWithoutExtensions() {
+		MavenBuild build = new MavenBuild();
+		generatePom(build, (pom) -> assertThat(pom).nodeAtPath("/project/build/extensions").isNull());
+	}
+
+	@Test
+	void pomWithExtension() {
+		MavenBuild build = new MavenBuild();
+		build.extensions().add("com.example", "testExtension", "1.6.1");
+		generatePom(build, (pom) -> {
+			assertThat(pom).textAtPath("/project/build/extensions/extension/groupId").isEqualTo("com.example");
+			assertThat(pom).textAtPath("/project/build/extensions/extension/artifactId").isEqualTo("testExtension");
+			assertThat(pom).textAtPath("/project/build/extensions/extension/version").isEqualTo("1.6.1");
+		});
+	}
+
 	@Test
 	void pomWithEmptyBuild() {
 		MavenBuild build = new MavenBuild();
@@ -903,23 +920,6 @@ class MavenBuildWriterTests {
 		});
 	}
 
-	@Test
-	void pomWithoutExtensions() {
-		MavenBuild build = new MavenBuild();
-		generatePom(build, (pom) -> assertThat(pom).nodeAtPath("/project/build/extensions").isNull());
-	}
-
-	@Test
-	void pomWithExtension() {
-		MavenBuild build = new MavenBuild();
-		build.extensions().add("com.example", "testExtension", (builder) -> builder.version("1.6.1"));
-		generatePom(build, (pom) -> {
-			assertThat(pom).textAtPath("/project/build/extensions/extension/groupId").isEqualTo("com.example");
-			assertThat(pom).textAtPath("/project/build/extensions/extension/artifactId").isEqualTo("testExtension");
-			assertThat(pom).textAtPath("/project/build/extensions/extension/version").isEqualTo("1.6.1");
-		});
-	}
-
 	@Test
 	void pomWithDistributionManagementRepository() {
 		MavenBuild build = new MavenBuild();