Contract maven plugin - incremental test generation (#1361)

* Contract maven plugin - incremental test generation

* incremental stubs and stub jar generation

spring-cloud-contract-tools/spring-cloud-contract-maven-plugin/src/main/java/org/springframework/cloud/contract/maven/verifier/ChangeDetector.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2013-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.contract.maven.verifier;
+
+import java.io.File;
+
+import org.apache.maven.execution.MavenSession;
+import org.apache.maven.plugin.MojoExecution;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.shared.incremental.IncrementalBuildHelper;
+import org.apache.maven.shared.utils.io.DirectoryScanner;
+
+final class ChangeDetector {
+
+	private ChangeDetector() {
+	}
+
+	static boolean inputFilesChangeDetected(File contractsDirectory,
+			MojoExecution mojoExecution, MavenSession session)
+			throws MojoExecutionException {
+
+		IncrementalBuildHelper incrementalBuildHelper = new IncrementalBuildHelper(
+				mojoExecution, session);
+
+		DirectoryScanner scanner = incrementalBuildHelper.getDirectoryScanner();
+		scanner.setBasedir(contractsDirectory);
+		scanner.scan();
+		boolean changeDetected = incrementalBuildHelper.inputFileTreeChanged(scanner);
+		if (scanner.getIncludedFiles().length == 0) {
+			// at least one input file must exist to consider changed/unchanged
+			// return true to skip incremental build and make visible no input file at all
+			return true;
+		}
+		return changeDetected;
+	}
+
+}

spring-cloud-contract-tools/spring-cloud-contract-maven-plugin/src/main/java/org/springframework/cloud/contract/maven/verifier/ConvertMojo.java

@@ -23,6 +23,7 @@ import java.util.Map;
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.plugin.AbstractMojo;
+import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugins.annotations.Component;
 import org.apache.maven.plugins.annotations.LifecyclePhase;
@@ -37,6 +38,8 @@ import org.springframework.cloud.contract.verifier.config.ContractVerifierConfig
 import org.springframework.cloud.contract.verifier.converter.RecursiveFilesConverter;
 import org.springframework.cloud.contract.verifier.converter.ToYamlConverter;
 
+import static org.springframework.cloud.contract.maven.verifier.ChangeDetector.inputFilesChangeDetected;
+
 /**
  * Convert Spring Cloud Contract Verifier contracts into stubs mappings.
  * <p>
@@ -188,6 +191,19 @@ public class ConvertMojo extends AbstractMojo {
 	@Parameter(property = "failOnNoContracts", defaultValue = "true")
 	private boolean failOnNoContracts;
 
+	/**
+	 * If set to true then stubs are created only when contracts have changed since last
+	 * build.
+	 */
+	@Parameter(property = "incrementalContractStubs", defaultValue = "true")
+	private boolean incrementalContractStubs = true;
+
+	@Parameter(defaultValue = "${mojoExecution}", readonly = true, required = true)
+	private MojoExecution mojoExecution;
+
+	@Parameter(defaultValue = "${session}", readonly = true, required = true)
+	private MavenSession session;
+
 	@Override
 	public void execute() throws MojoExecutionException {
 		if (this.skip) {
@@ -205,7 +221,17 @@ public class ConvertMojo extends AbstractMojo {
 		config.setExcludeBuildFolders(this.excludeBuildFolders);
 		File contractsDirectory = locationOfContracts(config);
 		contractsDirectory = contractSubfolderIfPresent(contractsDirectory);
+
+		if (this.incrementalContractStubs && !inputFilesChangeDetected(contractsDirectory,
+				mojoExecution, session)) {
+			getLog().info("Nothing to generate - all stubs are up to date");
+			return;
+		}
+
 		File contractsDslDir = contractsDslDir(contractsDirectory);
+		LeftOverPrevention leftOverPrevention = new LeftOverPrevention(
+				this.stubsDirectory, mojoExecution, session);
+
 		File copiedContracts = copyContracts(rootPath, config, contractsDirectory);
 		if (this.convertToYaml) {
 			contractsDslDir = copiedContracts;
@@ -220,6 +246,7 @@ public class ConvertMojo extends AbstractMojo {
 				config.getExcludedFiles(), config.getIncludedContracts(),
 				config.isExcludeBuildFolders());
 		converter.processFiles();
+		leftOverPrevention.deleteLeftOvers();
 	}
 
 	private void convertBackedUpDslsToYaml(String rootPath,

spring-cloud-contract-tools/spring-cloud-contract-maven-plugin/src/main/java/org/springframework/cloud/contract/maven/verifier/GenerateStubsMojo.java

@@ -21,7 +21,9 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import org.apache.maven.execution.MavenSession;
 import org.apache.maven.plugin.AbstractMojo;
+import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
 import org.apache.maven.plugins.annotations.Component;
@@ -33,6 +35,8 @@ import org.apache.maven.project.MavenProjectHelper;
 import org.codehaus.plexus.archiver.Archiver;
 import org.codehaus.plexus.archiver.jar.JarArchiver;
 
+import static org.springframework.cloud.contract.maven.verifier.ChangeDetector.inputFilesChangeDetected;
+
 /**
  * Picks the converted .json files and creates a jar. Requires convert to be executed
  * first.
@@ -86,6 +90,19 @@ public class GenerateStubsMojo extends AbstractMojo {
 	@Parameter(defaultValue = "stubs")
 	private String classifier;
 
+	/**
+	 * If set to true then stubs jar is created only when stubs have changed since last
+	 * build.
+	 */
+	@Parameter(property = "incrementalContractStubsJar", defaultValue = "true")
+	private boolean incrementalContractStubsJar = true;
+
+	@Parameter(defaultValue = "${mojoExecution}", readonly = true, required = true)
+	private MojoExecution mojoExecution;
+
+	@Parameter(defaultValue = "${session}", readonly = true, required = true)
+	private MavenSession session;
+
 	/**
 	 * When enabled, this flag will tell stub runner to throw an exception when no stubs /
 	 * contracts were found.
@@ -111,6 +128,11 @@ public class GenerateStubsMojo extends AbstractMojo {
 					+ this.outputDirectory.getAbsolutePath()
 					+ "] .\nPlease make sure that spring-cloud-contract:convert was invoked");
 		}
+		if (this.incrementalContractStubsJar
+				&& !inputFilesChangeDetected(outputDirectory, mojoExecution, session)) {
+			getLog().info("Nothing to generate - stubs jar is up to date");
+			return;
+		}
 		File stubsJarFile = createStubJar(this.outputDirectory);
 		this.projectHelper.attachArtifact(this.project, "jar", this.classifier,
 				stubsJarFile);

spring-cloud-contract-tools/spring-cloud-contract-maven-plugin/src/main/java/org/springframework/cloud/contract/maven/verifier/GenerateTestsMojo.java

@@ -21,9 +21,11 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.model.Resource;
 import org.apache.maven.plugin.AbstractMojo;
+import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
 import org.apache.maven.plugins.annotations.LifecyclePhase;
@@ -245,6 +247,19 @@ public class GenerateTestsMojo extends AbstractMojo {
 	@Parameter(property = "failOnInProgress", defaultValue = "true")
 	private boolean failOnInProgress = true;
 
+	/**
+	 * If set to true then tests are created only when contracts have changed since last
+	 * build.
+	 */
+	@Parameter(property = "incrementalContractTests", defaultValue = "true")
+	private boolean incrementalContractTests = true;
+
+	@Parameter(defaultValue = "${mojoExecution}", readonly = true, required = true)
+	private MojoExecution mojoExecution;
+
+	@Parameter(defaultValue = "${session}", readonly = true, required = true)
+	private MavenSession session;
+
 	@Override
 	public void execute() throws MojoExecutionException, MojoFailureException {
 		if (this.skip || this.mavenTestSkip || this.skipTests) {
@@ -280,6 +295,13 @@ public class GenerateTestsMojo extends AbstractMojo {
 								this.contractsDirectory);
 		getLog().info(
 				"Directory with contract is present at [" + contractsDirectory + "]");
+
+		if (this.incrementalContractTests && !ChangeDetector
+				.inputFilesChangeDetected(contractsDirectory, mojoExecution, session)) {
+			getLog().info("Nothing to generate - all classes are up to date");
+			return;
+		}
+
 		setupConfig(config, contractsDirectory);
 		this.project
 				.addTestCompileSourceRoot(this.generatedTestSourcesDir.getAbsolutePath());
@@ -297,9 +319,12 @@ public class GenerateTestsMojo extends AbstractMojo {
 					+ this.baseClassMappings);
 		}
 		try {
+			LeftOverPrevention leftOverPrevention = new LeftOverPrevention(
+					this.generatedTestSourcesDir, mojoExecution, session);
 			TestGenerator generator = new TestGenerator(config);
 			int generatedClasses = generator.generate();
 			getLog().info("Generated " + generatedClasses + " test classes.");
+			leftOverPrevention.deleteLeftOvers();
 		}
 		catch (ContractVerifierException e) {
 			throw new MojoExecutionException(

spring-cloud-contract-tools/spring-cloud-contract-maven-plugin/src/main/java/org/springframework/cloud/contract/maven/verifier/LeftOverPrevention.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2013-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.contract.maven.verifier;
+
+import java.io.File;
+
+import org.apache.maven.execution.MavenSession;
+import org.apache.maven.plugin.MojoExecution;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.shared.incremental.IncrementalBuildHelper;
+import org.apache.maven.shared.incremental.IncrementalBuildHelperRequest;
+
+/**
+ * Prevents the following scenario:
+ *
+ * 1. Contract is added
+ *
+ * 2. Derived file is generated
+ *
+ * 3. Contract is deleted
+ *
+ * 4. Derived file still exists
+ */
+class LeftOverPrevention {
+
+	private final IncrementalBuildHelper incrementalBuildHelper;
+
+	private final File generatedDirectory;
+
+	LeftOverPrevention(File generatedDirectory, MojoExecution mojoExecution,
+			MavenSession session) throws MojoExecutionException {
+		this.generatedDirectory = generatedDirectory;
+		this.incrementalBuildHelper = new IncrementalBuildHelper(mojoExecution, session);
+		this.incrementalBuildHelper.beforeRebuildExecution(
+				new IncrementalBuildHelperRequest().outputDirectory(generatedDirectory));
+	}
+
+	void deleteLeftOvers() throws MojoExecutionException {
+		if (generatedDirectory.exists()) {
+			incrementalBuildHelper
+					.afterRebuildExecution(new IncrementalBuildHelperRequest()
+							.outputDirectory(generatedDirectory));
+		}
+	}
+
+}