Test with custom pattern converter

Author: felixbarny

log4j2-ecs-layout/src/test/java/co/elastic/logging/log4j2/AbstractLog4j2EcsLayoutTest.java

@@ -84,6 +84,12 @@ void testMapMessage() throws Exception {
         assertThat(log.get("foo").textValue()).isEqualTo("bar");
     }
 
+    @Test
+    void testCustomPatternConverter() throws Exception {
+        debug("test");
+        assertThat(getLastLogLine().get("custom").textValue()).isEqualTo("foo");
+    }
+
     @Override
     public void putMdc(String key, String value) {
         ThreadContext.put(key, value);

log4j2-ecs-layout/src/test/java/co/elastic/logging/log4j2/CustomPatternConverter.java

@@ -0,0 +1,49 @@
+/*-
+ * #%L
+ * Java ECS logging
+ * %%
+ * Copyright (C) 2019 Elastic and contributors
+ * %%
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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.
+ * #L%
+ */
+package co.elastic.logging.log4j2;
+
+import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.pattern.ConverterKeys;
+import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
+import org.apache.logging.log4j.core.pattern.PatternConverter;
+
+@Plugin(category = PatternConverter.CATEGORY, name = "CustomPatternConverter")
+@ConverterKeys({"custom"})
+public class CustomPatternConverter extends LogEventPatternConverter {
+
+    public CustomPatternConverter(final String[] options) {
+        super("Custom", "custom");
+    }
+
+    public static CustomPatternConverter newInstance(final String[] options) {
+        return new CustomPatternConverter(options);
+    }
+
+    @Override
+    public void format(LogEvent event, StringBuilder toAppendTo) {
+        toAppendTo.append("foo");
+    }
+}

log4j2-ecs-layout/src/test/java/co/elastic/logging/log4j2/Log4j2EcsLayoutTest.java

@@ -76,6 +76,7 @@ void setUp() {
                         new KeyValuePair("node.id", "${node.id}"),
                         new KeyValuePair("empty", "${empty}"),
                         new KeyValuePair("clazz", "%C"),
+                        new KeyValuePair("custom", "%custom"),
                         new KeyValuePair("emptyPattern", "%notEmpty{%invalidPattern}"),
                 })
                 .build();

log4j2-ecs-layout/src/test/resources/log4j2-test.xml

@@ -10,6 +10,7 @@
                 <KeyValuePair key="node.id" value="${node.id}"/>
                 <KeyValuePair key="empty" value="${empty}"/>
                 <KeyValuePair key="clazz" value="%C"/>
+                <KeyValuePair key="custom" value="%custom"/>
                 <KeyValuePair key="emptyPattern" value="%notEmpty{%invalidPattern}"/>
             </EcsLayout>
         </List>