Added StringMatchFilterTest with test XMLs

Author: jethomas-tsi

log4j-core-test/src/test/java/org/apache/logging/log4j/core/filter/StringMatchFilterTest.java

@@ -0,0 +1,70 @@
+package org.apache.logging.log4j.core.filter;
+
+import org.apache.logging.log4j.core.Filter;
+import org.apache.logging.log4j.core.config.Configuration;
+import org.apache.logging.log4j.core.test.junit.LoggerContextSource;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+/**
+ * Unit test for {@link StringMatchFilter}.
+ */
+public class StringMatchFilterTest {
+
+  /**
+   * Test that if no match-string is set on the builder, the '{@link StringMatchFilter.Builder#build()}' returns
+   * {@code null}.
+   */
+  @Test
+  public void testFilterBuilderFailsWithNullText() {
+    Assertions.assertNull(StringMatchFilter.newBuilder().build());
+  }
+
+  /**
+   * Test that if a {@code null} string is set as a match-pattern, an {@code IllegalArgumentExeption} is thrown.
+   */
+  @Test
+  void testFilterBuilderFailsWithExceptionOnNullText() {
+    Assertions.assertThrows(IllegalArgumentException.class, () -> StringMatchFilter.newBuilder().setMatchString(null));
+  }
+
+  /**
+   * Test that if an empty ({@code ""}) string is set as a match-pattern, an {@code IllegalArgumentException} is thrown.
+   */
+  @Test
+  void testFilterBuilderFailsWithExceptionOnEmptyText() {
+    Assertions.assertThrows(IllegalArgumentException.class, () -> StringMatchFilter.newBuilder().setMatchString(""));
+  }
+
+  /**
+   * Test that if a {@link StringMatchFilter} is specified with a 'text' attribute it is correctly instantiated.
+   *
+   * @param configuration the configuration
+   */
+  @Test
+  @LoggerContextSource("log4j2-stringmatchfilter-3153-ok.xml")
+  void testConfigurationWithTextPOS(final Configuration configuration) {
+    final Filter filter = configuration.getFilter();
+    assertNotNull(filter, "The filter should not be null.");
+    assertInstanceOf(StringMatchFilter.class, filter, "Expected a StringMatchFilter, but got: " + filter.getClass());
+    assertEquals("FooBar", filter.toString());
+  }
+
+  /**
+   * Test that if a {@link StringMatchFilter} is specified without a 'text' attribute it is not instantiated.
+   *
+   * @param configuration the configuration
+   */
+  @Test
+  @LoggerContextSource("log4j2-stringmatchfilter-3153-nok.xml")
+  void testConfigurationWithTextNEG(final Configuration configuration) {
+    final Filter filter = configuration.getFilter();
+    assertNull(filter, "The filter should be null.");
+  }
+
+}

log4j-core-test/src/test/resources/log4j2-stringmatchfilter-3153-nok.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Licensed to the Apache Software Foundation (ASF) under one or more
+  ~ contributor license agreements.  See the NOTICE file distributed with
+  ~ this work for additional information regarding copyright ownership.
+  ~ The ASF 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.
+  -->
+<Configuration status="warn">
+   <StringMatchFfilter/>
+</Configuration>

log4j-core-test/src/test/resources/log4j2-stringmatchfilter-3153-ok.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Licensed to the Apache Software Foundation (ASF) under one or more
+  ~ contributor license agreements.  See the NOTICE file distributed with
+  ~ this work for additional information regarding copyright ownership.
+  ~ The ASF 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.
+  -->
+<Configuration status="warn">
+   <StringMatchFilter text="FooBar"/>
+</Configuration>