DefaultThreadContextMapTest.java

/*
 * 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.
 */
package org.apache.logging.log4j.spi;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.util.HashMap;
import java.util.Map;

import org.junit.Test;

/**
 * Tests the {@code DefaultThreadContextMap} class.
 */
public class DefaultThreadContextMapTest {

    @Test
    public void testEqualsVsSameKind() {
        final DefaultThreadContextMap map1 = createMap();
        final DefaultThreadContextMap map2 = createMap();
        assertEquals(map1, map1);
        assertEquals(map2, map2);
        assertEquals(map1, map2);
        assertEquals(map2, map1);
    }

    @Test
    public void testHashCodeVsSameKind() {
        final DefaultThreadContextMap map1 = createMap();
        final DefaultThreadContextMap map2 = createMap();
        assertEquals(map1.hashCode(), map2.hashCode());
    }

    @Test
    public void testDoesNothingIfConstructedWithUseMapIsFalse() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(false);
        assertTrue(map.isEmpty());
        assertFalse(map.containsKey("key"));
        map.put("key", "value");

        assertTrue(map.isEmpty());
        assertFalse(map.containsKey("key"));
        assertNull(map.get("key"));
    }

    @Test
    public void testPut() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        assertTrue(map.isEmpty());
        assertFalse(map.containsKey("key"));
        map.put("key", "value");

        assertFalse(map.isEmpty());
        assertTrue(map.containsKey("key"));
        assertEquals("value", map.get("key"));
    }

    @Test
    public void testPutAll() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        assertTrue(map.isEmpty());
        assertFalse(map.containsKey("key"));
        final int mapSize = 10;
        final Map<String, String> newMap = new HashMap<>(mapSize);
        for (int i = 1; i <= mapSize; i++) {
            newMap.put("key" + i, "value" + i);
        }
        map.putAll(newMap);
        assertFalse(map.isEmpty());
        for (int i = 1; i <= mapSize; i++) {
            assertTrue(map.containsKey("key" + i));
            assertEquals("value" + i, map.get("key" + i));
        }
    }

    /**
     * Test method for
     * {@link org.apache.logging.log4j.spi.DefaultThreadContextMap#remove(java.lang.String)}
     * .
     */
    @Test
    public void testRemove() {
        final DefaultThreadContextMap map = createMap();
        assertEquals("value", map.get("key"));
        assertEquals("value2", map.get("key2"));

        map.remove("key");
        assertFalse(map.containsKey("key"));
        assertEquals("value2", map.get("key2"));
    }

    @Test
    public void testClear() {
        final DefaultThreadContextMap map = createMap();

        map.clear();
        assertTrue(map.isEmpty());
        assertFalse(map.containsKey("key"));
        assertFalse(map.containsKey("key2"));
    }

    /**
     * @return
     */
    private DefaultThreadContextMap createMap() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        assertTrue(map.isEmpty());
        map.put("key", "value");
        map.put("key2", "value2");
        assertEquals("value", map.get("key"));
        assertEquals("value2", map.get("key2"));
        return map;
    }
    
    @Test
    public void testGetCopyReturnsMutableMap() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        assertTrue(map.isEmpty());
        final Map<String, String> copy = map.getCopy();
        assertTrue(copy.isEmpty());

        copy.put("key", "value"); // mutable
        assertEquals("value", copy.get("key"));

        // thread context map not affected
        assertTrue(map.isEmpty());
    }

    @Test
    public void testGetCopyReturnsMutableCopy() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        map.put("key1", "value1");
        assertFalse(map.isEmpty());
        final Map<String, String> copy = map.getCopy();
        assertEquals("value1", copy.get("key1")); // copy has values too

        copy.put("key", "value"); // copy is mutable
        assertEquals("value", copy.get("key"));

        // thread context map not affected
        assertFalse(map.containsKey("key"));

        // clearing context map does not affect copy
        map.clear();
        assertTrue(map.isEmpty());

        assertFalse(copy.isEmpty());
    }

    @Test
    public void testGetImmutableMapReturnsNullIfEmpty() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        assertTrue(map.isEmpty());
        assertNull(map.getImmutableMapOrNull());
    }

    @Test(expected = UnsupportedOperationException.class)
    public void testGetImmutableMapReturnsImmutableMapIfNonEmpty() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        map.put("key1", "value1");
        assertFalse(map.isEmpty());

        final Map<String, String> immutable = map.getImmutableMapOrNull();
        assertEquals("value1", immutable.get("key1")); // copy has values too

        // immutable
        immutable.put("key", "value"); // error
    }

    @Test
    public void testGetImmutableMapCopyNotAffectdByContextMapChanges() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        map.put("key1", "value1");
        assertFalse(map.isEmpty());

        final Map<String, String> immutable = map.getImmutableMapOrNull();
        assertEquals("value1", immutable.get("key1")); // copy has values too

        // clearing context map does not affect copy
        map.clear();
        assertTrue(map.isEmpty());

        assertFalse(immutable.isEmpty());
    }

    @Test
    public void testToStringShowsMapContext() {
        final DefaultThreadContextMap map = new DefaultThreadContextMap(true);
        assertEquals("{}", map.toString());

        map.put("key1", "value1");
        assertEquals("{key1=value1}", map.toString());

        map.remove("key1");
        map.put("key2", "value2");
        assertEquals("{key2=value2}", map.toString());
    }

    @Test
    public void testThreadLocalNotInheritableByDefault() {
        System.clearProperty(DefaultThreadContextMap.INHERITABLE_MAP);
        final ThreadLocal<Map<String, String>> threadLocal = DefaultThreadContextMap.createThreadLocalMap(true);
        assertFalse(threadLocal instanceof InheritableThreadLocal<?>);
    }
    
    @Test
    public void testThreadLocalInheritableIfConfigured() {
        System.setProperty(DefaultThreadContextMap.INHERITABLE_MAP, "true");
        try {
            final ThreadLocal<Map<String, String>> threadLocal = DefaultThreadContextMap.createThreadLocalMap(true);
            assertTrue(threadLocal instanceof InheritableThreadLocal<?>);
        } finally {
            System.clearProperty(DefaultThreadContextMap.INHERITABLE_MAP);
        }
    }
}