Merge pull request #1650 from dsyer

* pr/1650:
  Polish "Add support for processing instructions (e.g. m2e) in plugin"
  Add support for processing instructions (e.g. m2e) in plugin

Closes gh-1650

Author: mhalbritter

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

@@ -454,6 +454,10 @@ else if (setting.getValue() instanceof List) {
 
 	private void writePluginExecution(IndentingWriter writer, Execution execution) {
 		writeElement(writer, "execution", () -> {
+			List<String> processingInstructions = execution.getProcessingInstructions();
+			for (String instruction : processingInstructions) {
+				writeProcessingInstruction(writer, instruction);
+			}
 			writeSingleElement(writer, "id", execution.getId());
 			writeSingleElement(writer, "phase", execution.getPhase());
 			List<String> goals = execution.getGoals();
@@ -636,6 +640,10 @@ private void writeSingleElement(IndentingWriter writer, String name, Object valu
 		}
 	}
 
+	private void writeProcessingInstruction(IndentingWriter writer, String content) {
+		writer.println(String.format("<?%s?>", content));
+	}
+
 	private void writeElement(IndentingWriter writer, String name, Runnable withContent) {
 		writer.println(String.format("<%s>", name));
 		writer.indented(withContent);

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

@@ -286,6 +286,8 @@ public static class ExecutionBuilder {
 
 		private final List<String> goals = new ArrayList<>();
 
+		private final List<String> processingInstructions = new ArrayList<>();
+
 		private ConfigurationBuilder configurationCustomization = null;
 
 		/**
@@ -298,7 +300,8 @@ public ExecutionBuilder(String id) {
 
 		Execution build() {
 			return new Execution(this.id, this.phase, this.goals,
-					(this.configurationCustomization == null) ? null : this.configurationCustomization.build());
+					(this.configurationCustomization == null) ? null : this.configurationCustomization.build(),
+					this.processingInstructions);
 		}
 
 		/**
@@ -321,6 +324,25 @@ public ExecutionBuilder goal(String goal) {
 			return this;
 		}
 
+		/**
+		 * Add a processing instruction to invoke for this execution.
+		 * @param content the processing instruction to add
+		 * @return this for method chaining
+		 */
+		public ExecutionBuilder processingInstruction(String content) {
+			this.processingInstructions.add(content);
+			return this;
+		}
+
+		/**
+		 * Add a m2e hint, e.g. "execute onConfiguration,onIncremental" or "ignore".
+		 * @param hint the hint to add
+		 * @return this for method chaining
+		 */
+		public ExecutionBuilder m2e(String hint) {
+			return processingInstruction("m2e " + hint);
+		}
+
 		/**
 		 * Customize the {@code configuration} of the execution using the specified
 		 * consumer.
@@ -487,11 +509,15 @@ public static final class Execution {
 
 		private final Configuration configuration;
 
-		private Execution(String id, String phase, List<String> goals, Configuration configuration) {
+		private final List<String> processingInstructions;
+
+		private Execution(String id, String phase, List<String> goals, Configuration configuration,
+				List<String> processingInstructions) {
 			this.id = id;
 			this.phase = phase;
 			this.goals = Collections.unmodifiableList(goals);
 			this.configuration = configuration;
+			this.processingInstructions = processingInstructions;
 		}
 
 		/**
@@ -526,6 +552,10 @@ public Configuration getConfiguration() {
 			return this.configuration;
 		}
 
+		public List<String> getProcessingInstructions() {
+			return this.processingInstructions;
+		}
+
 	}
 
 	/**

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

@@ -30,6 +30,7 @@
 import io.spring.initializr.generator.version.VersionProperty;
 import io.spring.initializr.generator.version.VersionReference;
 import org.junit.jupiter.api.Test;
+import org.w3c.dom.Node;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -685,6 +686,37 @@ void pomWithPluginWithExecution() {
 		});
 	}
 
+	@Test
+	void pomWithPluginWithExecutionAndIdeHint() {
+		MavenBuild build = new MavenBuild();
+		build.settings().coordinates("com.example.demo", "demo");
+		build.plugins().add("org.asciidoctor", "asciidoctor-maven-plugin", (plugin) -> {
+			plugin.version("1.5.3");
+			plugin.execution("generateProject-docs", (execution) -> {
+				execution.m2e("ignore");
+				execution.goal("process-asciidoc");
+			});
+		});
+		generatePom(build, (pom) -> {
+			NodeAssert plugin = pom.nodeAtPath("/project/build/plugins/plugin");
+			assertThat(plugin).textAtPath("groupId").isEqualTo("org.asciidoctor");
+			assertThat(plugin).textAtPath("artifactId").isEqualTo("asciidoctor-maven-plugin");
+			assertThat(plugin).textAtPath("version").isEqualTo("1.5.3");
+			NodeAssert execution = plugin.nodeAtPath("executions/execution");
+			assertThat(execution).textAtPath("id").isEqualTo("generateProject-docs");
+			assertThat(execution).matches((node) -> {
+				Node child = node.getFirstChild();
+				while (child != null) {
+					if (child.getNodeType() == Node.PROCESSING_INSTRUCTION_NODE) {
+						return child.getNodeName().equals("m2e") && child.getTextContent().equals("ignore");
+					}
+					child = child.getNextSibling();
+				}
+				return false;
+			}, "m2e:ignore");
+		});
+	}
+
 	@Test
 	void pomWithPluginWithDependency() {
 		MavenBuild build = new MavenBuild();