squah-confluent commented on code in PR #22485: URL: https://github.com/apache/kafka/pull/22485#discussion_r3388309584
########## group-coordinator/src/test/java/org/apache/kafka/coordinator/group/util/OverlayMapTest.java: ########## @@ -0,0 +1,376 @@ +/* + * 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.kafka.coordinator.group.util; + +import org.junit.jupiter.api.Test; + +import java.util.HashMap; +import java.util.Iterator; +import java.util.LinkedHashMap; +import java.util.Map; +import java.util.NoSuchElementException; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertNull; +import static org.junit.jupiter.api.Assertions.assertThrows; +import static org.junit.jupiter.api.Assertions.assertTrue; + +public class OverlayMapTest { + + // Test simple additions, replacements and removals. This is enough to populate the three + // internal fields of OverlayMap for use in the rest of the tests. + + @Test + public void testPutNewKey() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "existing", "v1" + )); + + assertNull(map.put("new", "x")); + + assertEquals("x", map.get("new")); + } + + @Test + public void testPutExistingKey() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "existing", "v1" + )); + + assertEquals("v1", map.put("existing", "v2")); + + assertEquals("v2", map.get("existing")); + } + + @Test + public void testRemoveExistingKey() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "existing", "v1" + )); + + assertEquals("v1", map.remove("existing")); + + assertNull(map.get("existing")); + } + + // Now test everything else. + + /** + * Returns a map whose state populates all three overlay regions plus an untouched base key. + * Effective contents: {@code {addition=addition-value, replacement=replacement-new, base=base-value}}. + */ + private static OverlayMap<String, String> populated() { + Map<String, String> base = Map.of( + "replacement", "replacement-base", + "removal", "removal-base", + "base", "base-value" + ); + OverlayMap<String, String> map = new OverlayMap<>(base); + map.put("addition", "addition-value"); + map.put("replacement", "replacement-new"); + map.remove("removal"); + return map; + } + + @Test + public void testSize() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "base", "base-value", + "replacement", "replacement-value", + "removal", "removal-value" + )); + assertEquals(3, map.size()); + + // Additions increase the size. + map.put("addition", "addition-value"); + assertEquals(4, map.size()); + + // Replacements do not change the size. + map.put("replacement", "replacement-value-2"); + assertEquals(4, map.size()); + + // Removals decrease the size. + map.remove("removal"); + assertEquals(3, map.size()); + } + + @Test + public void testIsEmptyWithEmptyBase() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of()); + assertTrue(map.isEmpty()); + + // Additions make it non-empty. + map.put("k", "v"); + assertFalse(map.isEmpty()); + } + + @Test + public void testIsEmptyWhenAllBaseRemoved() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "k1", "v1", + "k2", "v2" + )); + + map.remove("k1"); + assertFalse(map.isEmpty()); + + map.remove("k2"); + assertTrue(map.isEmpty()); + } + + @Test + public void testContainsKey() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "base", "base-value", + "replacement", "replacement-value", + "removal", "removal-value" + )); + map.put("addition", "addition-value"); + map.put("replacement", "replacement-value-2"); + map.remove("removal"); + + assertTrue(map.containsKey("addition")); + assertTrue(map.containsKey("replacement")); + assertFalse(map.containsKey("removal")); + assertTrue(map.containsKey("base")); + assertFalse(map.containsKey("unknown")); + } + + @Test + public void testGet() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "base", "base-value", + "replacement", "replacement-value", + "removal", "removal-value" + )); + map.put("addition", "addition-value"); + map.put("replacement", "replacement-value-2"); + map.remove("removal"); + + assertEquals("addition-value", map.get("addition")); + assertEquals("replacement-value-2", map.get("replacement")); + assertNull(map.get("removal")); + assertEquals("base-value", map.get("base")); + assertNull(map.get("unknown")); + } + + @Test + public void testPut() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "base", "base-value", + "replacement", "replacement-value", + "removal", "removal-value" + )); + map.put("addition", "addition-value"); + map.put("replacement", "replacement-value-2"); + map.remove("removal"); + + assertEquals(3, map.size()); + + // Replace a new value. + assertEquals("addition-value", map.put("addition", "addition-value-2")); + assertEquals(3, map.size()); + assertTrue(map.containsKey("addition")); + assertEquals("addition-value-2", map.get("addition")); + assertEquals(Map.of( + "addition", "addition-value-2", + "replacement", "replacement-value-2", + "base", "base-value" + ), map); + + // Replace an already-replaced value. + assertEquals("replacement-value-2", map.put("replacement", "replacement-value-3")); + assertEquals(3, map.size()); + assertTrue(map.containsKey("replacement")); + assertEquals("replacement-value-3", map.get("replacement")); + assertEquals(Map.of( + "addition", "addition-value-2", + "replacement", "replacement-value-3", + "base", "base-value" + ), map); + + // Replace a removed value. + assertNull(map.put("removal", "removal-value-2")); + assertEquals(4, map.size()); + assertTrue(map.containsKey("removal")); + assertEquals("removal-value-2", map.get("removal")); + assertEquals(Map.of( + "addition", "addition-value-2", + "replacement", "replacement-value-3", + "removal", "removal-value-2", + "base", "base-value" + ), map); + + // Put over a base value and put over an unknown value are already test separately in + // testPutExistingKey and testPutNewKey. + } + + @Test + public void testRemove() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "base", "base-value", + "replacement", "replacement-value", + "removal", "removal-value" + )); + map.put("addition", "addition-value"); + map.put("replacement", "replacement-value-2"); + map.remove("removal"); + + assertEquals(3, map.size()); + + // Remove a new value. + assertEquals("addition-value", map.remove("addition")); + assertEquals(2, map.size()); + assertFalse(map.containsKey("addition")); + assertNull(map.get("addition")); + assertEquals(Map.of( + "replacement", "replacement-value-2", + "base", "base-value" + ), map); + + // Remove a replaced value. + assertEquals("replacement-value-2", map.remove("replacement")); + assertEquals(1, map.size()); + assertFalse(map.containsKey("replacement")); + assertNull(map.get("replacement")); + assertEquals(Map.of( + "base", "base-value" + ), map); + + // Remove a removed value. + assertNull(map.remove("removal")); + assertEquals(1, map.size()); + assertFalse(map.containsKey("removal")); + assertNull(map.get("removal")); + assertEquals(Map.of( + "base", "base-value" + ), map); + + // Remove an unknown value. + assertNull(map.remove("unknown")); + assertEquals(1, map.size()); + assertFalse(map.containsKey("unknown")); + assertNull(map.get("unknown")); + assertEquals(Map.of( + "base", "base-value" + ), map); + + // Removing a base value is already tested separately in testRemoveExistingKey. + } + + @Test + public void testClear() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "base", "base-value", + "replacement", "replacement-value", + "removal", "removal-value" + )); + map.put("addition", "addition-value"); + map.put("replacement", "replacement-value-2"); + map.remove("removal"); + map.clear(); + + assertEquals(0, map.size()); + assertTrue(map.isEmpty()); + assertFalse(map.containsKey("addition")); + assertFalse(map.containsKey("replacement")); + assertFalse(map.containsKey("base")); + assertNull(map.get("addition")); + assertNull(map.get("base")); + } + + @Test + public void testEntrySet() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "base", "base-value", + "replacement", "replacement-value", + "removal", "removal-value" + )); + map.put("addition", "addition-value"); + map.put("replacement", "replacement-value-2"); + map.remove("removal"); + + assertEquals( + Map.of( + "addition", "addition-value", + "replacement", "replacement-value-2", + "base", "base-value" + ), + new HashMap<>(map) + ); + } + + @Test + public void testEntrySetIterator() { + Map<String, String> base = new LinkedHashMap<>(); + base.put("base", "base-value"); + base.put("replacement", "replacement-value"); + base.put("removal", "removal-value"); + + OverlayMap<String, String> map = new OverlayMap<>(base); + map.put("addition", "addition-value"); + map.put("replacement", "replacement-value-2"); + map.remove("removal"); + + Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator(); + + assertTrue(iterator.hasNext()); + assertEquals(Map.entry("base", "base-value"), iterator.next()); + + assertTrue(iterator.hasNext()); + assertEquals(Map.entry("replacement", "replacement-value-2"), iterator.next()); + + assertTrue(iterator.hasNext()); + assertEquals(Map.entry("addition", "addition-value"), iterator.next()); + + assertFalse(iterator.hasNext()); + assertThrows(NoSuchElementException.class, iterator::next); + } + + @Test + public void testEntrySetIteratorOverEmptyMap() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of()); + + Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator(); + + assertFalse(iterator.hasNext()); + assertThrows(NoSuchElementException.class, iterator::next); + } + + @Test + public void testEntrySetSize() { + OverlayMap<String, String> map = new OverlayMap<>(Map.of( + "base", "base-value", + "replacement", "replacement-value", + "removal", "removal-value" + )); + assertEquals(3, map.entrySet().size()); + + // Additions increase the size. + map.put("addition", "addition-value"); + assertEquals(4, map.entrySet().size()); + + // Replacements do not change the size. + map.put("replacement", "replacement-value-2"); + assertEquals(4, map.entrySet().size()); + + // Removals decrease the size. + map.remove("removal"); + assertEquals(3, map.entrySet().size()); + } Review Comment: Good question. It turns out that null replacements are not supported because `Map.entry()` disallows nulls and throws. To support null values, we can replace `Map.entry` with `AbstractMap.SimpleImmutableEntry`. But since we don't require the ability to store `null` values in #22486, I'd rather not add all the extra tests. Instead I'll add a null check in `put()`. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
