Convert SpotlessTaskModern to use InputChanges API

plugin-gradle/src/main/java/com/diffplug/gradle/spotless/SpotlessTaskModern.java

@@ -24,9 +24,16 @@
 import java.util.stream.Collectors;
 
 import org.gradle.api.GradleException;
+import org.gradle.api.file.FileCollection;
 import org.gradle.api.tasks.CacheableTask;
+import org.gradle.api.tasks.InputFiles;
+import org.gradle.api.tasks.PathSensitive;
+import org.gradle.api.tasks.PathSensitivity;
 import org.gradle.api.tasks.TaskAction;
-import org.gradle.api.tasks.incremental.IncrementalTaskInputs;
+import org.gradle.work.ChangeType;
+import org.gradle.work.FileChange;
+import org.gradle.work.Incremental;
+import org.gradle.work.InputChanges;
 
 import com.diffplug.common.base.Errors;
 import com.diffplug.common.base.Preconditions;
@@ -35,10 +42,17 @@
 
 @CacheableTask
 public class SpotlessTaskModern extends SpotlessTask {
-	@TaskAction
-	public void performAction(IncrementalTaskInputs inputs) throws Exception {
-		// TODO: implement using the InputChanges api
 
+	@PathSensitive(PathSensitivity.RELATIVE)
+	@Incremental
+	@InputFiles
+	@Override
+	public FileCollection getTarget() {
+		return super.getTarget();
+	}
+
+	@TaskAction
+	public void performAction(InputChanges inputs) throws Exception {
 		if (target == null) {
 			throw new GradleException("You must specify 'Iterable<File> target'");
 		}
@@ -68,27 +82,27 @@ public void performAction(IncrementalTaskInputs inputs) throws Exception {
 		}
 
 		try (Formatter formatter = buildFormatter()) {
-			inputs.outOfDate(inputDetails -> {
-				File input = inputDetails.getFile();
-				try {
-					if (shouldInclude.test(input) && input.isFile()) {
-						processInputFile(formatter, input);
+			for (FileChange fileChange : inputs.getFileChanges(target)) {
+				File input = fileChange.getFile();
+				if (fileChange.getChangeType() == ChangeType.REMOVED) {
+					try {
+						if (shouldInclude.test(input)) {
+							deletePreviousResult(input);
+						}
+					} catch (IOException e) {
+						throw Errors.asRuntime(e);
 					}
-				} catch (IOException e) {
-					throw Errors.asRuntime(e);
-				}
-			});
-		}
 
-		inputs.removed(removedDetails -> {
-			File input = removedDetails.getFile();
-			try {
-				if (shouldInclude.test(input)) {
-					deletePreviousResult(input);
+				} else {
+					try {
+						if (shouldInclude.test(input) && input.isFile()) {
+							processInputFile(formatter, input);
+						}
+					} catch (IOException e) {
+						throw Errors.asRuntime(e);
+					}
 				}
-			} catch (IOException e) {
-				throw Errors.asRuntime(e);
 			}
-		});
+		}
 	}
 }

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/ConfigAvoidanceTest.java

@@ -23,7 +23,7 @@
 
 public class ConfigAvoidanceTest extends GradleIntegrationHarness {
 	protected final GradleRunner gradleRunnerConfigAvoidance() throws IOException {
-		return gradleRunner().withGradleVersion(SpotlessPluginPreConfigAvoidance.CONFIG_AVOIDANCE_INTRODUCED.getVersion());
+		return gradleRunner().withGradleVersion(GradleVersionSupport.CONFIG_AVOIDANCE.version);
 	}
 
 	@Test

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/ErrorShouldRethrowJre8Test.java

@@ -123,15 +123,15 @@ private void runWithSuccess(String... messages) throws Exception {
 		if (JreVersion.thisVm() != JreVersion._8) {
 			return;
 		}
-		BuildResult result = gradleRunner().withGradleVersion(SpotlessPluginModern.MINIMUM_GRADLE).withArguments("check").build();
+		BuildResult result = gradleRunner().withGradleVersion(GradleVersionSupport.MODERN.version).withArguments("check").build();
 		assertResultAndMessages(result, TaskOutcome.SUCCESS, messages);
 	}
 
 	private void runWithFailure(String... messages) throws Exception {
 		if (JreVersion.thisVm() != JreVersion._8) {
 			return;
 		}
-		BuildResult result = gradleRunner().withGradleVersion(SpotlessPluginModern.MINIMUM_GRADLE).withArguments("check").buildAndFail();
+		BuildResult result = gradleRunner().withGradleVersion(GradleVersionSupport.MODERN.version).withArguments("check").buildAndFail();
 		assertResultAndMessages(result, TaskOutcome.FAILED, messages);
 	}
 

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/GradleIntegrationHarness.java

@@ -39,6 +39,39 @@
 import com.diffplug.spotless.ResourceHarness;
 
 public class GradleIntegrationHarness extends ResourceHarness {
+	public enum GradleVersionSupport {
+		LEGACY("2.14"), KOTLIN("4.0"), CONFIG_AVOIDANCE("4.9"), MODERN(SpotlessPluginModern.MINIMUM_GRADLE), SETTINGS_PLUGINS("6.0");
+
+		final String version;
+
+		GradleVersionSupport(String version) {
+			this.version = adaptGradleVersionForJdk(adaptGradleVersionForModern(version));
+		}
+	}
+
+	protected static String adaptGradleVersionForModern(String ver) {
+		if ("true".equals(System.getProperty(SpotlessPluginModern.SPOTLESS_MODERN))) {
+			return Double.parseDouble(ver) < Double.parseDouble(SpotlessPluginModern.MINIMUM_GRADLE) ? SpotlessPluginModern.MINIMUM_GRADLE : ver;
+		}
+		return ver;
+	}
+
+	/**
+	 * For Java 11+, Gradle 5 is the minimum.
+	 * So if you ask for less than Gradle 5, you get it on Java 8, but on Java 11 you get promoted to Gradle 5.
+	 * If you ask for more than Gradle 5, you'll definitely get it.
+	 */
+	protected static String adaptGradleVersionForJdk(String ver) {
+		JreVersion jre = JreVersion.thisVm();
+		// @formatter:off
+		switch (jre) {
+			case _8:  return ver;
+			case _11: return Double.parseDouble(ver) < 5.0 ? "5.0" : ver;
+			default:  throw new IllegalStateException("Spotless build is only supported on Java 8 and Java 11");
+		}
+		// @formatter:on
+	}
+
 	/**
 	 * Each test gets its own temp folder, and we create a gradle
 	 * build there and run it.
@@ -58,30 +91,14 @@ public void gitAttributes() throws IOException {
 		setFile(".gitattributes").toContent("* text eol=lf");
 	}
 
-	/**
-	 * For Java 11+, Gradle 5 is the minimum.
-	 * So if you ask for less than Gradle 5, you get it on Java 8, but on Java 11 you get promoted to Gradle 5.
-	 * If you ask for more than Gradle 5, you'll definitely get it.
-	 */
-	protected static String requestGradleForJre8and11(String ver) {
-		JreVersion jre = JreVersion.thisVm();
-		// @formatter:off
-		switch (jre) {
-		case _8:  return ver;
-		case _11: return Double.parseDouble(ver) < 5.0 ? "5.0" : ver;
-		default:  throw new IllegalStateException("Spotless build is only supported on Java 8 and Java 11");
-		}
-		// @formatter:on
-	}
-
 	protected final GradleRunner gradleRunner() throws IOException {
 		GradleRunner runner = GradleRunner.create()
-				.withGradleVersion(requestGradleForJre8and11("2.14"))
+				.withGradleVersion(GradleVersionSupport.LEGACY.version)
 				.withProjectDir(rootFolder())
 				.withPluginClasspath();
 		if ("true".equals(System.getProperty(SpotlessPluginModern.SPOTLESS_MODERN))) {
 			runner.withEnvironment(ImmutableMap.of("ORG_GRADLE_PROJECT_" + SpotlessPluginModern.SPOTLESS_MODERN, "true"));
-			runner.withGradleVersion(SpotlessPluginModern.MINIMUM_GRADLE);
+			runner.withGradleVersion(GradleVersionSupport.MODERN.version);
 		}
 		return runner;
 	}

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/IdeHookTest.java

@@ -70,7 +70,7 @@ private void runWith(String... arguments) throws IOException {
 			// gradle 4.7 -> 5.1 don't work in tooling API because of https://github.com/gradle/gradle/issues/7617
 			// gradle 5.1 -> current confirmed to work
 			gradleRunner()
-					.withGradleVersion(SpotlessPluginModern.MINIMUM_GRADLE)
+					.withGradleVersion(GradleVersionSupport.MODERN.version)
 					.withProjectDir(rootFolder())
 					.withPluginClasspath()
 					.withArguments(arguments)

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/MultiProjectAfterEvaluate.java

@@ -39,6 +39,6 @@ public void failureDoesntTriggerAll() throws IOException {
 	}
 
 	private final GradleRunner gradleRunner6() throws IOException {
-		return gradleRunner().withGradleVersion("6.0");
+		return gradleRunner().withGradleVersion(GradleVersionSupport.MODERN.version);
 	}
 }

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/RatchetFromTest.java

@@ -116,11 +116,11 @@ private void assertDirty() throws Exception {
 	}
 
 	private BuildResultAssertion assertPass(String... tasks) throws Exception {
-		return new BuildResultAssertion(gradleRunner().withGradleVersion("6.0").withArguments(tasks).build());
+		return new BuildResultAssertion(gradleRunner().withGradleVersion(GradleVersionSupport.SETTINGS_PLUGINS.version).withArguments(tasks).build());
 	}
 
 	private BuildResultAssertion assertFail(String... tasks) throws Exception {
-		return new BuildResultAssertion(gradleRunner().withGradleVersion("6.0").withArguments(tasks).buildAndFail());
+		return new BuildResultAssertion(gradleRunner().withGradleVersion(GradleVersionSupport.SETTINGS_PLUGINS.version).withArguments(tasks).buildAndFail());
 	}
 
 	private static final String BASELINE_ROOT = "ebb03d6940ee0254010e71917735efa203c27e16";

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/RegisterDependenciesTaskTest.java

@@ -39,7 +39,7 @@ public void registerDependencies() throws IOException {
 				"}");
 
 		setFile("gradle.properties").toLines();
-		String newestSupported = gradleRunner().withGradleVersion(SpotlessPluginModern.MINIMUM_GRADLE)
+		String newestSupported = gradleRunner().withGradleVersion(GradleVersionSupport.MODERN.version)
 				.withArguments("spotlessCheck").build().getOutput();
 		Assertions.assertThat(newestSupported.replace("\r", ""))
 				.startsWith("> Task :spotlessCheck UP-TO-DATE\n" +

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/SpecificFilesTest.java

@@ -116,7 +116,7 @@ private void integration(String patterns,
 		GradleRunner runner = gradleRunner()
 				.withArguments("spotlessApply", "-PspotlessFiles=" + patterns);
 		if (isKotlin) {
-			runner.withGradleVersion(requestGradleForJre8and11("4.0"));
+			runner.withGradleVersion(GradleVersionSupport.KOTLIN.version);
 		}
 		runner.build();