Files
spring-boot-rest/java-collections-maps/src/test/java/com/baeldung/map/MapUnitTest.java
2019-09-24 07:18:08 -06:00

337 lines
9.4 KiB
Java

package com.baeldung.map;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.*;
import java.util.Map.Entry;
import static org.junit.Assert.*;
public class MapUnitTest {
private static final Logger LOG = LoggerFactory.getLogger(MapUnitTest.class);
@Test
public void givenHashMap_whenRetrievesKeyset_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("name", "baeldung");
map.put("type", "blog");
Set<String> keys = map.keySet();
assertEquals(2, keys.size());
assertTrue(keys.contains("name"));
assertTrue(keys.contains("type"));
}
@Test
public void givenHashMap_whenRetrievesValues_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("name", "baeldung");
map.put("type", "blog");
Collection<String> values = map.values();
assertEquals(2, values.size());
assertTrue(values.contains("baeldung"));
assertTrue(values.contains("blog"));
}
@Test
public void givenHashMap_whenRetrievesEntries_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("name", "baeldung");
map.put("type", "blog");
Set<Entry<String, String>> entries = map.entrySet();
assertEquals(2, entries.size());
for (Entry<String, String> e : entries) {
String key = e.getKey();
String val = e.getValue();
assertTrue(key.equals("name") || key.equals("type"));
assertTrue(val.equals("baeldung") || val.equals("blog"));
}
}
@Test
public void givenKeySet_whenChangeReflectsInMap_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("name", "baeldung");
map.put("type", "blog");
assertEquals(2, map.size());
Set<String> keys = map.keySet();
keys.remove("name");
assertEquals(1, map.size());
}
@Test(expected = ConcurrentModificationException.class)
public void givenIterator_whenFailsFastOnModification_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("name", "baeldung");
map.put("type", "blog");
Set<String> keys = map.keySet();
Iterator<String> it = keys.iterator();
map.remove("type");
while (it.hasNext()) {
String key = it.next();
}
}
public void givenIterator_whenRemoveWorks_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("name", "baeldung");
map.put("type", "blog");
Set<String> keys = map.keySet();
Iterator<String> it = keys.iterator();
while (it.hasNext()) {
it.next();
it.remove();
}
assertEquals(0, map.size());
}
@Test
public void whenHashCodeIsCalledOnPut_thenCorrect() {
MyKey key = new MyKey(1, "name");
Map<MyKey, String> map = new HashMap<>();
map.put(key, "val");
}
@Test
public void whenHashCodeIsCalledOnGet_thenCorrect() {
MyKey key = new MyKey(1, "name");
Map<MyKey, String> map = new HashMap<>();
map.put(key, "val");
map.get(key);
}
@Test
public void whenGetWorks_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("key", "val");
String val = map.get("key");
assertEquals("val", val);
}
@Test
public void givenNewKey_whenPutReturnsNull_thenCorrect() {
Map<String, String> map = new HashMap<>();
String rtnVal = map.put("key1", "val1");
assertNull(rtnVal);
}
@Test
public void givenUnmappedKey_whenGetReturnsNull_thenCorrect() {
Map<String, String> map = new HashMap<>();
String rtnVal = map.get("key1");
assertNull(rtnVal);
}
@Test
public void givenNullVal_whenPutReturnsNull_thenCorrect() {
Map<String, String> map = new HashMap<>();
String rtnVal = map.put("key1", null);
assertNull(rtnVal);
}
@Test
public void givenNullKeyAndVal_whenAccepts_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put(null, null);
}
@Test
public void givenNullVal_whenRetrieves_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("key", null);
String val = map.get("key");
assertNull(val);
}
@Test
public void whenContainsDistinguishesNullValues_thenCorrect() {
Map<String, String> map = new HashMap<>();
String val1 = map.get("key");
boolean valPresent = map.containsKey("key");
assertNull(val1);
assertFalse(valPresent);
map.put("key", null);
String val = map.get("key");
valPresent = map.containsKey("key");
assertNull(val);
assertTrue(valPresent);
}
@Test
public void whenPutReturnsPrevValue_thenCorrect() {
Map<String, String> map = new HashMap<>();
map.put("key1", "val1");
String rtnVal = map.put("key1", "val2");
assertEquals("val1", rtnVal);
}
@Test
public void whenCallsEqualsOnCollision_thenCorrect() {
HashMap<MyKey, String> map = new HashMap<>();
MyKey k1 = new MyKey(1, "firstKey");
MyKey k2 = new MyKey(2, "secondKey");
MyKey k3 = new MyKey(2, "thirdKey");
LOG.debug("storing value for k1");
map.put(k1, "firstValue");
LOG.debug("storing value for k2");
map.put(k2, "secondValue");
LOG.debug("storing value for k3");
map.put(k3, "thirdValue");
LOG.debug("retrieving value for k1");
String v1 = map.get(k1);
LOG.debug("retrieving value for k2");
String v2 = map.get(k2);
LOG.debug("retrieving value for k3");
String v3 = map.get(k3);
assertEquals("firstValue", v1);
assertEquals("secondValue", v2);
assertEquals("thirdValue", v3);
}
@Test
public void givenLinkedHashMap_whenGetsOrderedKeyset_thenCorrect() {
LinkedHashMap<Integer, String> map = new LinkedHashMap<>();
map.put(1, null);
map.put(2, null);
map.put(3, null);
map.put(4, null);
map.put(5, null);
Set<Integer> keys = map.keySet();
Integer[] arr = keys.toArray(new Integer[0]);
for (int i = 0; i < arr.length; i++) {
assertEquals(new Integer(i + 1), arr[i]);
}
}
@Test
public void givenLinkedHashMap_whenAccessOrderWorks_thenCorrect() {
LinkedHashMap<Integer, String> map = new LinkedHashMap<>(16, .75f, true);
map.put(1, null);
map.put(2, null);
map.put(3, null);
map.put(4, null);
map.put(5, null);
Set<Integer> keys = map.keySet();
assertEquals("[1, 2, 3, 4, 5]", keys.toString());
map.get(4);
assertEquals("[1, 2, 3, 5, 4]", keys.toString());
map.get(1);
assertEquals("[2, 3, 5, 4, 1]", keys.toString());
map.get(3);
assertEquals("[2, 5, 4, 1, 3]", keys.toString());
}
@Test
public void givenLinkedHashMap_whenRemovesEldestEntry_thenCorrect() {
LinkedHashMap<Integer, String> map = new MyLinkedHashMap<>(16, .75f, true);
map.put(1, null);
map.put(2, null);
map.put(3, null);
map.put(4, null);
map.put(5, null);
Set<Integer> keys = map.keySet();
assertEquals("[1, 2, 3, 4, 5]", keys.toString());
map.put(6, null);
assertEquals("[2, 3, 4, 5, 6]", keys.toString());
map.put(7, null);
assertEquals("[3, 4, 5, 6, 7]", keys.toString());
map.put(8, null);
assertEquals("[4, 5, 6, 7, 8]", keys.toString());
}
@Test
public void givenTreeMap_whenOrdersEntriesNaturally_thenCorrect() {
TreeMap<Integer, String> map = new TreeMap<>();
map.put(3, "val");
map.put(2, "val");
map.put(1, "val");
map.put(5, "val");
map.put(4, "val");
assertEquals("[1, 2, 3, 4, 5]", map.keySet().toString());
}
@Test
public void givenTreeMap_whenOrdersEntriesNaturally_thenCorrect2() {
TreeMap<String, String> map = new TreeMap<>();
map.put("c", "val");
map.put("b", "val");
map.put("a", "val");
map.put("e", "val");
map.put("d", "val");
assertEquals("[a, b, c, d, e]", map.keySet().toString());
}
@Test
public void givenTreeMap_whenOrdersEntriesByComparator_thenCorrect() {
TreeMap<Integer, String> map = new TreeMap<>(Comparator.reverseOrder());
map.put(3, "val");
map.put(2, "val");
map.put(1, "val");
map.put(5, "val");
map.put(4, "val");
assertEquals("[5, 4, 3, 2, 1]", map.keySet().toString());
}
@Test
public void givenTreeMap_whenPerformsQueries_thenCorrect() {
TreeMap<Integer, String> map = new TreeMap<>();
map.put(3, "val");
map.put(2, "val");
map.put(1, "val");
map.put(5, "val");
map.put(4, "val");
Integer highestKey = map.lastKey();
Integer lowestKey = map.firstKey();
Set<Integer> keysLessThan3 = map.headMap(3).keySet();
Set<Integer> keysGreaterThanEqTo3 = map.tailMap(3).keySet();
assertEquals(new Integer(5), highestKey);
assertEquals(new Integer(1), lowestKey);
assertEquals("[1, 2]", keysLessThan3.toString());
assertEquals("[3, 4, 5]", keysGreaterThanEqTo3.toString());
}
}