1162: use slf4j for logging

Author: simschla

lib/src/main/java/com/diffplug/spotless/LazyArgLogger.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2023 DiffPlug
+ *
+ * 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
+ *
+ *     http://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 com.diffplug.spotless;
+
+import java.util.function.Supplier;
+
+/**
+ * This is a utility class to allow for lazy evaluation of arguments to be passed to a logger
+ * and thus avoid unnecessary computation of the arguments if the log level is not enabled.
+ */
+public final class LazyArgLogger {
+
+	private final Supplier<Object> argSupplier;
+
+	private LazyArgLogger(Supplier<Object> argSupplier) {
+		this.argSupplier = argSupplier;
+	}
+
+	public static LazyArgLogger lazy(Supplier<Object> argSupplier) {
+		return new LazyArgLogger(argSupplier);
+	}
+
+	@Override
+	public String toString() {
+		return String.valueOf(argSupplier.get());
+	}
+}

lib/src/main/java/com/diffplug/spotless/npm/EslintFormatterStep.java

@@ -15,6 +15,7 @@
  */
 package com.diffplug.spotless.npm;
 
+import static com.diffplug.spotless.LazyArgLogger.lazy;
 import static java.util.Objects.requireNonNull;
 
 import java.io.File;
@@ -115,7 +116,7 @@ protected void prepareNodeServerLayout() throws IOException {
 				// If any config files are provided, we need to make sure they are at the same location as the node modules
 				// as eslint will try to resolve plugin/config names relatively to the config file location and some
 				// eslint configs contain relative paths to additional config files (such as tsconfig.json e.g.)
-				FormattedPrinter.SYSOUT.print("Copying config file <%s> to <%s> and using the copy", origEslintConfig.getEslintConfigPath(), nodeServerLayout.nodeModulesDir());
+				logger.info("Copying config file <{}> to <{}> and using the copy", origEslintConfig.getEslintConfigPath(), nodeServerLayout.nodeModulesDir());
 				File configFileCopy = NpmResourceHelper.copyFileToDir(origEslintConfig.getEslintConfigPath(), nodeServerLayout.nodeModulesDir());
 				this.eslintConfigInUse = this.origEslintConfig.withEslintConfigPath(configFileCopy).verify();
 			}
@@ -125,7 +126,7 @@ protected void prepareNodeServerLayout() throws IOException {
 		@Nonnull
 		public FormatterFunc createFormatterFunc() {
 			try {
-				FormattedPrinter.SYSOUT.print("creating formatter function (starting server)");
+				logger.info("Creating formatter function (starting server)");
 				ServerProcessInfo eslintRestServer = npmRunServer();
 				EslintRestService restService = new EslintRestService(eslintRestServer.getBaseUrl());
 				return Closeable.ofDangerous(() -> endServer(restService, eslintRestServer), new EslintFilePathPassingFormatterFunc(locations.projectDir(), nodeServerLayout.nodeModulesDir(), eslintConfigInUse, restService));
@@ -135,7 +136,7 @@ public FormatterFunc createFormatterFunc() {
 		}
 
 		private void endServer(BaseNpmRestService restService, ServerProcessInfo restServer) throws Exception {
-			FormattedPrinter.SYSOUT.print("Closing formatting function (ending server).");
+			logger.info("Closing formatting function (ending server).");
 			try {
 				restService.shutdown();
 			} catch (Throwable t) {
@@ -161,7 +162,7 @@ public EslintFilePathPassingFormatterFunc(File projectDir, File nodeModulesDir,
 
 		@Override
 		public String applyWithFile(String unix, File file) throws Exception {
-			FormattedPrinter.SYSOUT.print("formatting String '" + unix.substring(0, Math.min(50, unix.length())) + "[...]' in file '" + file + "'");
+			logger.info("formatting String '{}[...]' in file '{}'", lazy(() -> unix.substring(0, Math.min(50, unix.length()))), file);
 
 			Map<FormatOption, Object> eslintCallOptions = new HashMap<>();
 			setConfigToCallOptions(eslintCallOptions);

lib/src/main/java/com/diffplug/spotless/npm/FormattedPrinter.java

@@ -15,6 +15,7 @@
  */
 package com.diffplug.spotless.npm;
 
+import static com.diffplug.spotless.LazyArgLogger.lazy;
 import static java.util.Objects.requireNonNull;
 
 import java.io.File;
@@ -86,7 +87,7 @@ private static class State extends NpmFormatterStepStateBase implements Serializ
 		@Nonnull
 		public FormatterFunc createFormatterFunc() {
 			try {
-				FormattedPrinter.SYSOUT.print("creating formatter function (starting server)");
+				logger.info("creating formatter function (starting server)");
 				ServerProcessInfo prettierRestServer = npmRunServer();
 				PrettierRestService restService = new PrettierRestService(prettierRestServer.getBaseUrl());
 				String prettierConfigOptions = restService.resolveConfig(this.prettierConfig.getPrettierConfigPath(), this.prettierConfig.getOptions());
@@ -97,7 +98,7 @@ public FormatterFunc createFormatterFunc() {
 		}
 
 		private void endServer(PrettierRestService restService, ServerProcessInfo restServer) throws Exception {
-			FormattedPrinter.SYSOUT.print("Closing formatting function (ending server).");
+			logger.info("Closing formatting function (ending server).");
 			try {
 				restService.shutdown();
 			} catch (Throwable t) {
@@ -119,7 +120,7 @@ public PrettierFilePathPassingFormatterFunc(String prettierConfigOptions, Pretti
 
 		@Override
 		public String applyWithFile(String unix, File file) throws Exception {
-			FormattedPrinter.SYSOUT.print("formatting String '" + unix.substring(0, Math.min(50, unix.length())) + "[...]' in file '" + file + "'");
+			logger.info("formatting String '{}[...]' in file '{}'", lazy(() -> unix.substring(0, Math.min(50, unix.length()))), file);
 
 			final String prettierConfigOptionsWithFilepath = assertFilepathInConfigOptions(file);
 			try {

lib/src/main/java/com/diffplug/spotless/npm/PrettierFormatterStep.java

@@ -219,8 +219,10 @@ void usePhpAndJavaCommunityPlugin() throws IOException {
 				"}");
 		setFile("php-example.php").toResource("npm/prettier/plugins/php.dirty");
 		setFile("JavaTest.java").toResource("npm/prettier/plugins/java-test.dirty");
-		final BuildResult spotlessApply = gradleRunner().withArguments("--stacktrace", "spotlessApply").build();
+		final BuildResult spotlessApply = gradleRunner().forwardOutput().withArguments("--stacktrace", "--info", "spotlessApply").build();
 		Assertions.assertThat(spotlessApply.getOutput()).contains("BUILD SUCCESSFUL");
+		final BuildResult spotlessApply2 = gradleRunner().forwardOutput().withArguments("--stacktrace", "--info", "spotlessApply").build();
+		Assertions.assertThat(spotlessApply2.getOutput()).contains("BUILD SUCCESSFUL");
 		assertFile("php-example.php").sameAsResource("npm/prettier/plugins/php.clean");
 		assertFile("JavaTest.java").sameAsResource("npm/prettier/plugins/java-test.clean");
 	}