Add tests for LogbackLogstashStructuredLoggingFormatter

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/LogbackLogstashStructuredLoggingFormatter.java

@@ -20,11 +20,11 @@
 import java.time.ZoneId;
 import java.time.format.DateTimeFormatter;
 import java.util.Collections;
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.TreeSet;
 
 import ch.qos.logback.classic.pattern.ThrowableProxyConverter;
 import ch.qos.logback.classic.spi.ILoggingEvent;
@@ -104,7 +104,7 @@ private Set<String> getMarkers(ILoggingEvent event) {
 		if (CollectionUtils.isEmpty(event.getMarkerList())) {
 			return Collections.emptySet();
 		}
-		Set<String> result = new HashSet<>();
+		Set<String> result = new TreeSet<>();
 		for (Marker marker : event.getMarkerList()) {
 			addMarker(result, marker);
 		}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/logback/AbstractStructuredLoggingTests.java

@@ -31,7 +31,9 @@
 import org.assertj.core.api.Assertions;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
+import org.slf4j.Marker;
 import org.slf4j.event.KeyValuePair;
+import org.slf4j.helpers.BasicMarkerFactory;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -46,8 +48,11 @@ abstract class AbstractStructuredLoggingTests {
 
 	private ThrowableProxyConverter throwableProxyConverter;
 
+	private BasicMarkerFactory markerFactory;
+
 	@BeforeEach
 	void setUp() {
+		this.markerFactory = new BasicMarkerFactory();
 		this.throwableProxyConverter = new ThrowableProxyConverter();
 		this.throwableProxyConverter.start();
 	}
@@ -57,6 +62,10 @@ void tearDown() {
 		this.throwableProxyConverter.stop();
 	}
 
+	protected Marker getMarker(String name) {
+		return this.markerFactory.getDetachedMarker(name);
+	}
+
 	protected ThrowableProxyConverter getThrowableProxyConverter() {
 		return this.throwableProxyConverter;
 	}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogbackEcsStructuredLoggingFormatterTests.java

@@ -37,6 +37,7 @@ class LogbackEcsStructuredLoggingFormatterTests extends AbstractStructuredLoggin
 
 	private LogbackEcsStructuredLoggingFormatter formatter;
 
+	@Override
 	@BeforeEach
 	void setUp() {
 		super.setUp();

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogbackLogstashStructuredLoggingFormatterTests.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2012-2024 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.boot.logging.logback;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+import ch.qos.logback.classic.spi.LoggingEvent;
+import ch.qos.logback.classic.spi.ThrowableProxy;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.slf4j.Marker;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link LogbackLogstashStructuredLoggingFormatter}.
+ *
+ * @author Moritz Halbritter
+ */
+class LogbackLogstashStructuredLoggingFormatterTests extends AbstractStructuredLoggingTests {
+
+	private LogbackLogstashStructuredLoggingFormatter formatter;
+
+	@Override
+	@BeforeEach
+	void setUp() {
+		super.setUp();
+		this.formatter = new LogbackLogstashStructuredLoggingFormatter(getThrowableProxyConverter());
+	}
+
+	@Test
+	void shouldFormat() {
+		LoggingEvent event = createEvent();
+		event.setMDCPropertyMap(Map.of("mdc-1", "mdc-v-1"));
+		event.setKeyValuePairs(keyValuePairs("kv-1", "kv-v-1"));
+		Marker marker1 = getMarker("marker-1");
+		marker1.add(getMarker("marker-2"));
+		event.addMarker(marker1);
+		String json = this.formatter.format(event);
+		assertThat(json).endsWith("\n");
+		Map<String, Object> deserialized = deserialize(json);
+		assertThat(deserialized).containsExactlyInAnyOrderEntriesOf(
+				map("@timestamp", "2024-07-02T10:49:53+02:00", "@version", "1", "message", "message", "logger_name",
+						"org.example.Test", "thread_name", "main", "level", "INFO", "level_value", 20000, "mdc-1",
+						"mdc-v-1", "kv-1", "kv-v-1", "tags", List.of("marker-1", "marker-2")));
+	}
+
+	@Test
+	void shouldFormatException() {
+		LoggingEvent event = createEvent();
+		event.setThrowableProxy(new ThrowableProxy(new RuntimeException("Boom")));
+		event.setMDCPropertyMap(Collections.emptyMap());
+		String json = this.formatter.format(event);
+		Map<String, Object> deserialized = deserialize(json);
+		String stackTrace = (String) deserialized.get("stack_trace");
+		assertThat(stackTrace).startsWith(
+				"""
+						java.lang.RuntimeException: Boom
+						\tat org.springframework.boot.logging.logback.LogbackLogstashStructuredLoggingFormatterTests.shouldFormatException
+						"""
+					.trim());
+		assertThat(json).contains(
+				"""
+						java.lang.RuntimeException: Boom\\n\\tat org.springframework.boot.logging.logback.LogbackLogstashStructuredLoggingFormatterTests.shouldFormatException
+						"""
+					.trim());
+	}
+
+}