Prevent eager creation of bootWar task

Previously, querying the artifact's extension in
SinglePublishedArtifact would result in eager creation of the task
that creates the artifact. Typically, this is the bootWar task.

Instead of querying the extension, this commit reworks
SinglePublishedArtifact and its callers to call separate methods for
jar and war artifacts so that the extension check is no longer
required.

Tests have been added to ensure that running help does not trigger
any unexpected task creation. The tests' assertions tolerate some
variation in behavior that depend on the version of Gradle and
whether the configuration cache is enabled.

Closes gh-30211

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/JavaPluginAction.java

@@ -133,7 +133,7 @@ private void configureBootBuildImageTask(Project project, TaskProvider<BootJar>
 
 	private void configureArtifactPublication(TaskProvider<BootJar> bootJar) {
 		LazyPublishArtifact artifact = new LazyPublishArtifact(bootJar);
-		this.singlePublishedArtifact.addCandidate(artifact);
+		this.singlePublishedArtifact.addJarCandidate(artifact);
 	}
 
 	private void configureBootRunTask(Project project) {

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/SinglePublishedArtifact.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -38,14 +38,22 @@ final class SinglePublishedArtifact implements Buildable {
 		this.artifacts = artifacts;
 	}
 
-	void addCandidate(PublishArtifact candidate) {
-		if (this.currentArtifact == null || "war".equals(candidate.getExtension())) {
-			this.artifacts.remove(this.currentArtifact);
-			this.artifacts.add(candidate);
-			this.currentArtifact = candidate;
+	void addWarCandidate(PublishArtifact candidate) {
+		add(candidate);
+	}
+
+	void addJarCandidate(PublishArtifact candidate) {
+		if (this.currentArtifact == null) {
+			add(candidate);
 		}
 	}
 
+	private void add(PublishArtifact artifact) {
+		this.artifacts.remove(this.currentArtifact);
+		this.artifacts.add(artifact);
+		this.currentArtifact = artifact;
+	}
+
 	@Override
 	public TaskDependency getBuildDependencies() {
 		return this.artifacts.getBuildDependencies();

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/WarPluginAction.java

@@ -108,7 +108,7 @@ private void configureBootBuildImageTask(Project project, TaskProvider<BootWar>
 
 	private void configureArtifactPublication(TaskProvider<BootWar> bootWar) {
 		LazyPublishArtifact artifact = new LazyPublishArtifact(bootWar);
-		this.singlePublishedArtifact.addCandidate(artifact);
+		this.singlePublishedArtifact.addWarCandidate(artifact);
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/plugin/ApplicationPluginActionIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -16,19 +16,25 @@
 
 package org.springframework.boot.gradle.plugin;
 
+import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.io.StringReader;
 import java.util.ArrayList;
 import java.util.Enumeration;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.function.Consumer;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
 import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
 import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
+import org.gradle.testkit.runner.BuildResult;
 import org.gradle.testkit.runner.TaskOutcome;
+import org.gradle.util.GradleVersion;
 import org.junit.jupiter.api.TestTemplate;
 
 import org.springframework.boot.gradle.junit.GradleCompatibility;
@@ -154,6 +160,26 @@ void scriptsHaveCorrectPermissions() throws IOException {
 		});
 	}
 
+	@TestTemplate
+	void taskConfigurationIsAvoided() throws IOException {
+		BuildResult result = this.gradleBuild.build("help");
+		String output = result.getOutput();
+		BufferedReader reader = new BufferedReader(new StringReader(output));
+		String line;
+		Set<String> configured = new HashSet<>();
+		while ((line = reader.readLine()) != null) {
+			if (line.startsWith("Configuring :")) {
+				configured.add(line.substring("Configuring :".length()));
+			}
+		}
+		if (GradleVersion.version(this.gradleBuild.getGradleVersion()).compareTo(GradleVersion.version("7.3.3")) < 0) {
+			assertThat(configured).containsExactly("help");
+		}
+		else {
+			assertThat(configured).containsExactlyInAnyOrder("help", "clean");
+		}
+	}
+
 	private List<String> zipEntryNames(File distribution) throws IOException {
 		List<String> entryNames = new ArrayList<>();
 		try (ZipFile zipFile = new ZipFile(distribution)) {

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/plugin/JavaPluginActionIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -16,13 +16,18 @@
 
 package org.springframework.boot.gradle.plugin;
 
+import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.StringReader;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.jar.JarOutputStream;
 
 import org.gradle.testkit.runner.BuildResult;
 import org.gradle.testkit.runner.TaskOutcome;
+import org.gradle.util.GradleVersion;
 import org.junit.jupiter.api.TestTemplate;
 
 import org.springframework.boot.gradle.junit.GradleCompatibility;
@@ -159,6 +164,27 @@ void productionRuntimeClasspathIsConfiguredWithResolvabilityAndConsumabilityThat
 		assertThat(productionRuntime).contains("canBeConsumed: false");
 	}
 
+	@TestTemplate
+	void taskConfigurationIsAvoided() throws IOException {
+		BuildResult result = this.gradleBuild.build("help");
+		String output = result.getOutput();
+		BufferedReader reader = new BufferedReader(new StringReader(output));
+		String line;
+		Set<String> configured = new HashSet<>();
+		while ((line = reader.readLine()) != null) {
+			if (line.startsWith("Configuring :")) {
+				configured.add(line.substring("Configuring :".length()));
+			}
+		}
+		if (!this.gradleBuild.isConfigurationCache() && GradleVersion.version(this.gradleBuild.getGradleVersion())
+				.compareTo(GradleVersion.version("7.3.3")) < 0) {
+			assertThat(configured).containsExactly("help");
+		}
+		else {
+			assertThat(configured).containsExactlyInAnyOrder("help", "clean");
+		}
+	}
+
 	private void createMinimalMainSource() throws IOException {
 		File examplePackage = new File(this.gradleBuild.getProjectDir(), "src/main/java/com/example");
 		examplePackage.mkdirs();

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/plugin/KotlinPluginActionIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -16,6 +16,14 @@
 
 package org.springframework.boot.gradle.plugin;
 
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.gradle.testkit.runner.BuildResult;
+import org.gradle.util.GradleVersion;
 import org.junit.jupiter.api.TestTemplate;
 
 import org.springframework.boot.gradle.junit.GradleCompatibility;
@@ -57,4 +65,24 @@ void kotlinCompileTasksCanOverrideDefaultJavaParametersFlag() {
 				.contains("compileKotlin java parameters: false").contains("compileTestKotlin java parameters: false");
 	}
 
+	@TestTemplate
+	void taskConfigurationIsAvoided() throws IOException {
+		BuildResult result = this.gradleBuild.build("help");
+		String output = result.getOutput();
+		BufferedReader reader = new BufferedReader(new StringReader(output));
+		String line;
+		Set<String> configured = new HashSet<>();
+		while ((line = reader.readLine()) != null) {
+			if (line.startsWith("Configuring :")) {
+				configured.add(line.substring("Configuring :".length()));
+			}
+		}
+		if (GradleVersion.version(this.gradleBuild.getGradleVersion()).compareTo(GradleVersion.version("7.3.3")) < 0) {
+			assertThat(configured).containsExactly("help");
+		}
+		else {
+			assertThat(configured).containsExactlyInAnyOrder("help", "clean", "compileKotlin", "compileTestKotlin");
+		}
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/plugin/WarPluginActionIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -16,10 +16,16 @@
 
 package org.springframework.boot.gradle.plugin;
 
+import java.io.BufferedReader;
 import java.io.File;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.HashSet;
+import java.util.Set;
 
 import org.gradle.testkit.runner.BuildResult;
 import org.gradle.testkit.runner.TaskOutcome;
+import org.gradle.util.GradleVersion;
 import org.junit.jupiter.api.TestTemplate;
 
 import org.springframework.boot.gradle.junit.GradleCompatibility;
@@ -67,4 +73,24 @@ void errorMessageIsHelpfulWhenMainClassCannotBeResolved() {
 		assertThat(result.getOutput()).contains("Main class name has not been configured and it could not be resolved");
 	}
 
+	@TestTemplate
+	void taskConfigurationIsAvoided() throws IOException {
+		BuildResult result = this.gradleBuild.build("help");
+		String output = result.getOutput();
+		BufferedReader reader = new BufferedReader(new StringReader(output));
+		String line;
+		Set<String> configured = new HashSet<>();
+		while ((line = reader.readLine()) != null) {
+			if (line.startsWith("Configuring :")) {
+				configured.add(line.substring("Configuring :".length()));
+			}
+		}
+		if (GradleVersion.version(this.gradleBuild.getGradleVersion()).compareTo(GradleVersion.version("7.3.3")) < 0) {
+			assertThat(configured).containsExactly("help");
+		}
+		else {
+			assertThat(configured).containsExactlyInAnyOrder("help", "clean");
+		}
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/testkit/GradleBuild.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -150,6 +150,10 @@ public GradleBuild configurationCache() {
 		return this;
 	}
 
+	public boolean isConfigurationCache() {
+		return this.configurationCache;
+	}
+
 	public GradleBuild scriptProperty(String key, String value) {
 		this.scriptProperties.put(key, value);
 		return this;

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/plugin/ApplicationPluginActionIntegrationTests-taskConfigurationIsAvoided.gradle

@@ -0,0 +1,9 @@
+plugins {
+	id 'org.springframework.boot' version '{version}'
+	id 'java'
+	id 'application'
+}
+
+tasks.configureEach {
+	println "Configuring ${it.path}"
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/plugin/JavaPluginActionIntegrationTests-taskConfigurationIsAvoided.gradle

@@ -0,0 +1,8 @@
+plugins {
+	id 'org.springframework.boot' version '{version}'
+	id 'java'
+}
+
+tasks.configureEach {
+	println "Configuring ${it.path}"
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/plugin/KotlinPluginActionIntegrationTests-taskConfigurationIsAvoided.gradle

@@ -0,0 +1,9 @@
+plugins {
+	id 'org.springframework.boot' version '{version}'
+}
+
+apply plugin: 'org.jetbrains.kotlin.jvm'
+
+tasks.configureEach {
+	println "Configuring ${it.path}"
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/plugin/WarPluginActionIntegrationTests-taskConfigurationIsAvoided.gradle

@@ -0,0 +1,8 @@
+plugins {
+	id 'org.springframework.boot' version '{version}'
+	id 'war'
+}
+
+tasks.configureEach {
+	println "Configuring ${it.path}"
+}