Harmonize Maven build to use containers

Closes gh-996

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

@@ -36,24 +36,25 @@ public class MavenPlugin {
 
 	private final String artifactId;
 
-	private String version;
+	private final String version;
 
-	private final Map<String, ExecutionBuilder> executions = new LinkedHashMap<>();
+	private final boolean extensions;
 
-	private final List<Dependency> dependencies = new ArrayList<>();
+	private final List<Execution> executions;
 
-	private ConfigurationCustomization configurationCustomization = null;
+	private final List<Dependency> dependencies;
 
-	private boolean extensions;
+	private final Configuration configuration;
 
-	public MavenPlugin(String groupId, String artifactId) {
-		this(groupId, artifactId, null);
-	}
-
-	public MavenPlugin(String groupId, String artifactId, String version) {
-		this.groupId = groupId;
-		this.artifactId = artifactId;
-		this.version = version;
+	protected MavenPlugin(Builder builder) {
+		this.groupId = builder.groupId;
+		this.artifactId = builder.artifactId;
+		this.version = builder.version;
+		this.extensions = builder.extensions;
+		this.executions = Collections.unmodifiableList(
+				builder.executions.values().stream().map(ExecutionBuilder::build).collect(Collectors.toList()));
+		this.dependencies = Collections.unmodifiableList(new ArrayList<>(builder.dependencies));
+		this.configuration = (builder.configurationBuilder == null) ? null : builder.configurationBuilder.build();
 	}
 
 	public String getGroupId() {
@@ -68,50 +69,82 @@ public class MavenPlugin {
 		return this.version;
 	}
 
-	public void setVersion(String version) {
-		this.version = version;
-	}
-
-	public void configuration(Consumer<ConfigurationCustomization> consumer) {
-		if (this.configurationCustomization == null) {
-			this.configurationCustomization = new ConfigurationCustomization();
-		}
-		consumer.accept(this.configurationCustomization);
-	}
-
-	public void execution(String id, Consumer<ExecutionBuilder> customizer) {
-		customizer.accept(this.executions.computeIfAbsent(id, (key) -> new ExecutionBuilder(id)));
-	}
-
-	public List<Execution> getExecutions() {
-		return this.executions.values().stream().map(ExecutionBuilder::build).collect(Collectors.toList());
-	}
-
-	public void dependency(String groupId, String artifactId, String version) {
-		this.dependencies.add(new Dependency(groupId, artifactId, version));
-	}
-
-	public List<Dependency> getDependencies() {
-		return Collections.unmodifiableList(this.dependencies);
-	}
-
-	public Configuration getConfiguration() {
-		return (this.configurationCustomization == null) ? null : this.configurationCustomization.build();
-	}
-
 	public boolean isExtensions() {
 		return this.extensions;
 	}
 
-	/**
-	 * Enables loading plugin extensions.
-	 */
-	public void extensions() {
-		this.extensions = true;
+	public List<Execution> getExecutions() {
+		return this.executions;
+	}
+
+	public List<Dependency> getDependencies() {
+		return this.dependencies;
+	}
+
+	public Configuration getConfiguration() {
+		return this.configuration;
 	}
 
 	/**
-	 * Builder for creation an {@link Execution}.
+	 * Builder for a {@link MavenPlugin}.
+	 */
+	public static class Builder {
+
+		private final String groupId;
+
+		private final String artifactId;
+
+		private String version;
+
+		private boolean extensions;
+
+		private final Map<String, ExecutionBuilder> executions = new LinkedHashMap<>();
+
+		private final List<Dependency> dependencies = new ArrayList<>();
+
+		private ConfigurationBuilder configurationBuilder;
+
+		public Builder(String groupId, String artifactId) {
+			this.groupId = groupId;
+			this.artifactId = artifactId;
+		}
+
+		public Builder version(String version) {
+			this.version = version;
+			return this;
+		}
+
+		public Builder extensions() {
+			this.extensions = true;
+			return this;
+		}
+
+		public Builder configuration(Consumer<ConfigurationBuilder> consumer) {
+			if (this.configurationBuilder == null) {
+				this.configurationBuilder = new ConfigurationBuilder();
+			}
+			consumer.accept(this.configurationBuilder);
+			return this;
+		}
+
+		public Builder execution(String id, Consumer<ExecutionBuilder> customizer) {
+			customizer.accept(this.executions.computeIfAbsent(id, (key) -> new ExecutionBuilder(id)));
+			return this;
+		}
+
+		public Builder dependency(String groupId, String artifactId, String version) {
+			this.dependencies.add(new Dependency(groupId, artifactId, version));
+			return this;
+		}
+
+		public MavenPlugin build() {
+			return new MavenPlugin(this);
+		}
+
+	}
+
+	/**
+	 * Builder for an {@link Execution}.
 	 */
 	public static class ExecutionBuilder {
 
@@ -121,7 +154,7 @@ public class MavenPlugin {
 
 		private List<String> goals = new ArrayList<>();
 
-		private ConfigurationCustomization configurationCustomization = null;
+		private ConfigurationBuilder configurationCustomization = null;
 
 		public ExecutionBuilder(String id) {
 			this.id = id;
@@ -142,9 +175,9 @@ public class MavenPlugin {
 			return this;
 		}
 
-		public void configuration(Consumer<ConfigurationCustomization> consumer) {
+		public void configuration(Consumer<ConfigurationBuilder> consumer) {
 			if (this.configurationCustomization == null) {
-				this.configurationCustomization = new ConfigurationCustomization();
+				this.configurationCustomization = new ConfigurationBuilder();
 			}
 			consumer.accept(this.configurationCustomization);
 		}
@@ -152,9 +185,9 @@ public class MavenPlugin {
 	}
 
 	/**
-	 * Customization of a {@link Configuration}.
+	 * Builder for a {@link Configuration}.
 	 */
-	public static class ConfigurationCustomization {
+	public static class ConfigurationBuilder {
 
 		private final List<Setting> settings = new ArrayList<>();
 
@@ -164,7 +197,7 @@ public class MavenPlugin {
 		 * @param value the single value of the parameter
 		 * @return this for method chaining
 		 */
-		public ConfigurationCustomization add(String name, String value) {
+		public ConfigurationBuilder add(String name, String value) {
 			this.settings.add(new Setting(name, value));
 			return this;
 		}
@@ -177,18 +210,18 @@ public class MavenPlugin {
 		 * @throws IllegalArgumentException if a parameter with the same name is
 		 * registered with a single value
 		 */
-		public ConfigurationCustomization configure(String name, Consumer<ConfigurationCustomization> consumer) {
+		public ConfigurationBuilder configure(String name, Consumer<ConfigurationBuilder> consumer) {
 			Object value = this.settings.stream().filter((candidate) -> candidate.getName().equals(name)).findFirst()
 					.orElseGet(() -> {
-						Setting nestedSetting = new Setting(name, new ConfigurationCustomization());
+						Setting nestedSetting = new Setting(name, new ConfigurationBuilder());
 						this.settings.add(nestedSetting);
 						return nestedSetting;
 					}).getValue();
-			if (!(value instanceof ConfigurationCustomization)) {
+			if (!(value instanceof ConfigurationBuilder)) {
 				throw new IllegalArgumentException(String.format(
 						"Could not customize parameter '%s', a single value %s is already registered", name, value));
 			}
-			ConfigurationCustomization nestedConfiguration = (ConfigurationCustomization) value;
+			ConfigurationBuilder nestedConfiguration = (ConfigurationBuilder) value;
 			consumer.accept(nestedConfiguration);
 			return this;
 		}
@@ -199,8 +232,8 @@ public class MavenPlugin {
 		}
 
 		private Setting resolve(String key, Object value) {
-			if (value instanceof ConfigurationCustomization) {
-				List<Setting> values = ((ConfigurationCustomization) value).settings.stream()
+			if (value instanceof ConfigurationBuilder) {
+				List<Setting> values = ((ConfigurationBuilder) value).settings.stream()
 						.map((entry) -> resolve(entry.getName(), entry.getValue())).collect(Collectors.toList());
 				return new Setting(key, values);
 			}
@@ -219,11 +252,11 @@ public class MavenPlugin {
 		private final List<Setting> settings;
 
 		private Configuration(List<Setting> settings) {
-			this.settings = settings;
+			this.settings = Collections.unmodifiableList(settings);
 		}
 
 		public List<Setting> getSettings() {
-			return Collections.unmodifiableList(this.settings);
+			return this.settings;
 		}
 
 	}
@@ -268,7 +301,7 @@ public class MavenPlugin {
 		private Execution(String id, String phase, List<String> goals, Configuration configuration) {
 			this.id = id;
 			this.phase = phase;
-			this.goals = goals;
+			this.goals = Collections.unmodifiableList(goals);
 			this.configuration = configuration;
 		}
 

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

@@ -21,6 +21,8 @@ import java.util.Map;
 import java.util.function.Consumer;
 import java.util.stream.Stream;
 
+import io.spring.initializr.generator.buildsystem.maven.MavenPlugin.Builder;
+
 /**
  * A container for {@link MavenPlugin}s.
  *
@@ -28,7 +30,7 @@ import java.util.stream.Stream;
  */
 public class MavenPluginContainer {
 
-	private final Map<String, MavenPlugin> plugins = new LinkedHashMap<>();
+	private final Map<String, MavenPlugin.Builder> plugins = new LinkedHashMap<>();
 
 	/**
 	 * Specify if this container is empty.
@@ -55,7 +57,7 @@ public class MavenPluginContainer {
 	 * @return a stream of {@link MavenPlugin}s
 	 */
 	public Stream<MavenPlugin> values() {
-		return this.plugins.values().stream();
+		return this.plugins.values().stream().map(Builder::build);
 	}
 
 	/**
@@ -70,21 +72,20 @@ public class MavenPluginContainer {
 	}
 
 	/**
-	 * Add a {@link MavenPlugin}with the specified {@code groupId} and {@code artifactId}
-	 * and {@link Consumer} to customize the object. If the plugin has already been added,
+	 * Add a {@link MavenPlugin} with the specified {@code groupId} and {@code artifactId}
+	 * and {@link Consumer} to customize the plugin. If the plugin has already been added,
 	 * the consumer can be used to further tune the existing plugin configuration.
 	 * @param groupId the groupId of the plugin
 	 * @param artifactId the artifactId of the plugin
 	 * @param plugin a {@link Consumer} to customize the {@link MavenPlugin}
 	 */
-	public void add(String groupId, String artifactId, Consumer<MavenPlugin> plugin) {
-		MavenPlugin mavenPlugin = addPlugin(groupId, artifactId);
-		plugin.accept(mavenPlugin);
+	public void add(String groupId, String artifactId, Consumer<MavenPlugin.Builder> plugin) {
+		plugin.accept(addPlugin(groupId, artifactId));
 	}
 
-	private MavenPlugin addPlugin(String groupId, String artifactId) {
+	private MavenPlugin.Builder addPlugin(String groupId, String artifactId) {
 		return this.plugins.computeIfAbsent(pluginKey(groupId, artifactId),
-				(pluginId) -> new MavenPlugin(groupId, artifactId));
+				(pluginId) -> new MavenPlugin.Builder(groupId, artifactId));
 	}
 
 	/**

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

@@ -16,6 +16,7 @@
 
 package io.spring.initializr.generator.buildsystem.maven;
 
+import io.spring.initializr.generator.buildsystem.maven.MavenPlugin.Builder;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -76,7 +77,7 @@ class MavenBuildTests {
 	void mavenPluginVersionCanBeAmended() {
 		MavenBuild build = new MavenBuild();
 		build.plugins().add("com.example", "test-plugin");
-		build.plugins().add("com.example", "test-plugin", (plugin) -> plugin.setVersion("1.0.0"));
+		build.plugins().add("com.example", "test-plugin", (plugin) -> plugin.version("1.0.0"));
 		assertThat(build.plugins().values()).hasOnlyOneElementSatisfying((testPlugin) -> {
 			assertThat(testPlugin.getGroupId()).isEqualTo("com.example");
 			assertThat(testPlugin.getArtifactId()).isEqualTo("test-plugin");
@@ -88,8 +89,8 @@ class MavenBuildTests {
 	@Test
 	void mavenPluginVersionCanBeAmendedWithCustomizer() {
 		MavenBuild build = new MavenBuild();
-		build.plugins().add("com.example", "test-plugin", (plugin) -> plugin.setVersion("1.0.0"));
-		build.plugins().add("com.example", "test-plugin", (plugin) -> plugin.setVersion(null));
+		build.plugins().add("com.example", "test-plugin", (plugin) -> plugin.version("1.0.0"));
+		build.plugins().add("com.example", "test-plugin", (plugin) -> plugin.version(null));
 		assertThat(build.plugins().values()).hasOnlyOneElementSatisfying((testPlugin) -> {
 			assertThat(testPlugin.getGroupId()).isEqualTo("com.example");
 			assertThat(testPlugin.getArtifactId()).isEqualTo("test-plugin");
@@ -100,7 +101,7 @@ class MavenBuildTests {
 	@Test
 	void mavenPluginVersionIsNotLostOnAmend() {
 		MavenBuild build = new MavenBuild();
-		build.plugins().add("com.example", "test-plugin", (plugin) -> plugin.setVersion("1.0.0"));
+		build.plugins().add("com.example", "test-plugin", (plugin) -> plugin.version("1.0.0"));
 		build.plugins().add("com.example", "test-plugin");
 		assertThat(build.plugins().values()).hasOnlyOneElementSatisfying((testPlugin) -> {
 			assertThat(testPlugin.getGroupId()).isEqualTo("com.example");
@@ -134,7 +135,7 @@ class MavenBuildTests {
 	@Test
 	void mavenPluginExtensionsCanBeLoaded() {
 		MavenBuild build = new MavenBuild();
-		build.plugins().add("com.example", "test-plugin", MavenPlugin::extensions);
+		build.plugins().add("com.example", "test-plugin", Builder::extensions);
 		assertThat(build.plugins().values())
 				.hasOnlyOneElementSatisfying((testPlugin) -> assertThat(testPlugin.isExtensions()).isTrue());
 	}

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

@@ -392,7 +392,7 @@ class MavenBuildWriterTests {
 		MavenBuild build = new MavenBuild();
 		build.settings().coordinates("com.example.demo", "demo");
 		build.plugins().add("org.asciidoctor", "asciidoctor-maven-plugin", (plugin) -> {
-			plugin.setVersion("1.5.3");
+			plugin.version("1.5.3");
 			plugin.execution("generateProject-docs", (execution) -> {
 				execution.goal("process-asciidoc");
 				execution.phase("generateProject-resources");
@@ -438,7 +438,7 @@ class MavenBuildWriterTests {
 	void pomWithPluginWithExtensions() throws Exception {
 		MavenBuild build = new MavenBuild();
 		build.settings().coordinates("com.example.demo", "demo");
-		build.plugins().add("com.example.demo", "demo-plugin", MavenPlugin::extensions);
+		build.plugins().add("com.example.demo", "demo-plugin", MavenPlugin.Builder::extensions);
 		generatePom(build, (pom) -> {
 			NodeAssert plugin = pom.nodeAtPath("/project/build/plugins/plugin");
 			assertThat(plugin).textAtPath("groupId").isEqualTo("com.example.demo");

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

@@ -42,10 +42,8 @@ public class MavenPluginContainerTests {
 	@Test
 	void addPluginWithConsumer() {
 		MavenPluginContainer pluginContainer = new MavenPluginContainer();
-		pluginContainer.add("com.example", "test-plugin", (plugin) -> {
-			plugin.setVersion("1.0");
-			plugin.execution("first", (first) -> first.goal("run-this"));
-		});
+		pluginContainer.add("com.example", "test-plugin",
+				(plugin) -> plugin.version("1.0").execution("first", (first) -> first.goal("run-this")));
 		assertThat(pluginContainer.values()).hasOnlyOneElementSatisfying((plugin) -> {
 			assertThat(plugin.getGroupId()).isEqualTo("com.example");
 			assertThat(plugin.getArtifactId()).isEqualTo("test-plugin");
@@ -59,14 +57,8 @@ public class MavenPluginContainerTests {
 	@Test
 	void addPluginSeveralTimeReuseConfiguration() {
 		MavenPluginContainer pluginContainer = new MavenPluginContainer();
-		pluginContainer.add("com.example", "test-plugin", (plugin) -> {
-			assertThat(plugin.getVersion()).isNull();
-			plugin.setVersion("1.0");
-		});
-		pluginContainer.add("com.example", "test-plugin", (plugin) -> {
-			assertThat(plugin.getVersion()).isEqualTo("1.0");
-			plugin.setVersion("2.0");
-		});
+		pluginContainer.add("com.example", "test-plugin", (plugin) -> plugin.version("1.0"));
+		pluginContainer.add("com.example", "test-plugin", (plugin) -> plugin.version("2.0"));
 		assertThat(pluginContainer.values()).hasOnlyOneElementSatisfying((plugin) -> {
 			assertThat(plugin.getGroupId()).isEqualTo("com.example");
 			assertThat(plugin.getArtifactId()).isEqualTo("test-plugin");

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

@@ -18,6 +18,7 @@ package io.spring.initializr.generator.buildsystem.maven;
 
 import java.util.List;
 
+import io.spring.initializr.generator.buildsystem.maven.MavenPlugin.Builder;
 import io.spring.initializr.generator.buildsystem.maven.MavenPlugin.Setting;
 import org.junit.jupiter.api.Test;
 
@@ -33,9 +34,9 @@ class MavenPluginTests {
 
 	@Test
 	void configurationParameterCanBeCustomized() {
-		MavenPlugin plugin = new MavenPlugin("com.example", "test-plugin");
-		plugin.configuration((configuration) -> configuration.add("enabled", "false").add("skip", "true"));
-		plugin.configuration((configuration) -> configuration.add("another", "test"));
+		MavenPlugin plugin = plugin("com.example", "test-plugin")
+				.configuration((configuration) -> configuration.add("enabled", "false").add("skip", "true"))
+				.configuration((configuration) -> configuration.add("another", "test")).build();
 		assertThat(plugin.getConfiguration().getSettings().stream().map(Setting::getName)).containsExactly("enabled",
 				"skip", "another");
 		assertThat(plugin.getConfiguration().getSettings().stream().map(Setting::getValue)).containsExactly("false",
@@ -44,9 +45,9 @@ class MavenPluginTests {
 
 	@Test
 	void configurationParameterCanBeAdded() {
-		MavenPlugin plugin = new MavenPlugin("com.example", "test-plugin");
-		plugin.configuration((configuration) -> configuration.add("enabled", "true"));
-		plugin.configuration((configuration) -> configuration.add("skip", "false"));
+		MavenPlugin plugin = plugin("com.example", "test-plugin")
+				.configuration((configuration) -> configuration.add("enabled", "true"))
+				.configuration((configuration) -> configuration.add("skip", "false")).build();
 		assertThat(plugin.getConfiguration().getSettings().stream().map(Setting::getName)).containsExactly("enabled",
 				"skip");
 		assertThat(plugin.getConfiguration().getSettings().stream().map(Setting::getValue)).containsExactly("true",
@@ -56,9 +57,10 @@ class MavenPluginTests {
 	@Test
 	@SuppressWarnings("unchecked")
 	void configurationParameterWithNestedValuesCanBeCustomized() {
-		MavenPlugin plugin = new MavenPlugin("com.example", "test-plugin");
-		plugin.configuration((configuration) -> configuration.configure("items", (items) -> items.add("item", "one")));
-		plugin.configuration((configuration) -> configuration.configure("items", (items) -> items.add("item", "two")));
+		MavenPlugin plugin = plugin("com.example", "test-plugin")
+				.configuration((configuration) -> configuration.configure("items", (items) -> items.add("item", "one")))
+				.configuration((configuration) -> configuration.configure("items", (items) -> items.add("item", "two")))
+				.build();
 		assertThat(plugin.getConfiguration().getSettings()).hasSize(1);
 		Setting setting = plugin.getConfiguration().getSettings().get(0);
 		assertThat(setting.getName()).isEqualTo("items");
@@ -71,11 +73,15 @@ class MavenPluginTests {
 	@Test
 	@SuppressWarnings("unchecked")
 	void configurationParameterWithSeveralLevelOfNestedValuesCanBeCustomized() {
-		MavenPlugin plugin = new MavenPlugin("com.example", "test-plugin");
-		plugin.configuration((configuration) -> configuration.configure("items",
-				(items) -> items.configure("item", (subItems) -> subItems.add("subItem", "one"))));
-		plugin.configuration((configuration) -> configuration.configure("items", (items) -> items.configure("item",
-				(subItems) -> subItems.add("subItem", "two").add("subItem", "three"))));
+		MavenPlugin plugin = plugin("com.example", "test-plugin")
+				.configuration((configuration) -> configuration.configure("items",
+						(items) -> items.configure("item", (subItems) -> subItems.add("subItem", "one"))))
+				.configuration(
+						(configuration) -> configuration
+								.configure("items",
+										(items) -> items.configure("item",
+												(subItems) -> subItems.add("subItem", "two").add("subItem", "three"))))
+				.build();
 		assertThat(plugin.getConfiguration().getSettings()).hasSize(1);
 		Setting setting = plugin.getConfiguration().getSettings().get(0);
 		assertThat(setting.getName()).isEqualTo("items");
@@ -92,43 +98,46 @@ class MavenPluginTests {
 
 	@Test
 	void configurationParameterWithSingleValueCannotBeSwitchedToNestedValue() {
-		MavenPlugin plugin = new MavenPlugin("com.example", "test-plugin");
-		plugin.configuration((configuration) -> configuration.add("test", "value"));
+		MavenPlugin.Builder builder = plugin("com.example", "test-plugin")
+				.configuration((configuration) -> configuration.add("test", "value"));
 		assertThatIllegalArgumentException()
-				.isThrownBy(() -> plugin
+				.isThrownBy(() -> builder
 						.configuration((customizer) -> customizer.configure("test", (test) -> test.add("one", "true"))))
 				.withMessageContaining("test").withMessageContaining("value");
 	}
 
 	@Test
 	void executionPhasesCanBeOverridden() {
-		MavenPlugin plugin = new MavenPlugin("com.example", "test-plugin");
-		plugin.execution("test", (test) -> test.phase("compile"));
-		plugin.execution("test", (test) -> test.phase("process-resources"));
+		MavenPlugin plugin = plugin("com.example", "test-plugin").execution("test", (test) -> test.phase("compile"))
+				.execution("test", (test) -> test.phase("process-resources")).build();
 		assertThat(plugin.getExecutions()).hasSize(1);
 		assertThat(plugin.getExecutions().get(0).getPhase()).isEqualTo("process-resources");
 	}
 
 	@Test
 	void executionGoalsCanBeAmended() {
-		MavenPlugin plugin = new MavenPlugin("com.example", "test-plugin");
-		plugin.execution("test", (test) -> test.goal("first"));
-		plugin.execution("test", (test) -> test.goal("second"));
+		MavenPlugin plugin = plugin("com.example", "test-plugin").execution("test", (test) -> test.goal("first"))
+				.execution("test", (test) -> test.goal("second")).build();
 		assertThat(plugin.getExecutions()).hasSize(1);
 		assertThat(plugin.getExecutions().get(0).getGoals()).containsExactly("first", "second");
 	}
 
 	@Test
 	void executionConfigurationCanBeOverridden() {
-		MavenPlugin plugin = new MavenPlugin("com.example", "test-plugin");
-		plugin.execution("test",
-				(test) -> test.configuration((testConfiguration) -> testConfiguration.add("enabled", "true")));
-		plugin.execution("test",
-				(test) -> test.configuration((testConfiguration) -> testConfiguration.add("another", "test")));
+		MavenPlugin plugin = plugin("com.example", "test-plugin")
+				.execution("test",
+						(test) -> test.configuration((testConfiguration) -> testConfiguration.add("enabled", "true")))
+				.execution("test",
+						(test) -> test.configuration((testConfiguration) -> testConfiguration.add("another", "test")))
+				.build();
 		assertThat(plugin.getExecutions()).hasSize(1);
 		List<Setting> settings = plugin.getExecutions().get(0).getConfiguration().getSettings();
 		assertThat(settings.stream().map(Setting::getName)).containsExactly("enabled", "another");
 		assertThat(settings.stream().map(Setting::getValue)).containsExactly("true", "test");
 	}
 
+	private MavenPlugin.Builder plugin(String groupId, String artifactId) {
+		return new Builder(groupId, artifactId);
+	}
+
 }