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BAEL-5161 Added tests for updating the value of a key in a HashMap (#11300)

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Co-authored-by: Matea Pejčinović <matea.pejcinovic@intellexi.hr>
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Teica 2021-10-09 04:54:31 +02:00 committed by GitHub
parent 8430e9eaa8
commit b04e68e10b
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java-collections-maps-3/src/test/java/com/baeldung/map/hashing/HashMapUpdateUnitTest.java Normal file
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package com.baeldung.map.hashing;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestInstance;
import java.util.HashMap;
import java.util.Map;
import java.util.function.BiFunction;
@TestInstance(TestInstance.Lifecycle.PER_CLASS)
public class HashMapUpdateUnitTest {
Map<String, Double> fruitMap = new HashMap<>();
@BeforeAll
void setup() {
fruitMap.put("apple", 2.45);
fruitMap.put("grapes", 1.22);
}
@Test
public void givenFruitMap_whenPuttingAList_thenHashMapUpdatesAndInsertsValues() {
Double newValue = 2.11;
fruitMap.put("apple", newValue);
fruitMap.put("orange", newValue);
Assertions.assertEquals(newValue, fruitMap.get("apple"));
Assertions.assertTrue(fruitMap.containsKey("orange"));
Assertions.assertEquals(newValue, fruitMap.get("orange"));
}
@Test
public void givenFruitMap_whenKeyExists_thenValuesUpdated() {
double newValue = 2.31;
if (fruitMap.containsKey("apple")) {
fruitMap.put("apple", newValue);
}
Assertions.assertEquals(Double.valueOf(newValue), fruitMap.get("apple"));
}
@Test
public void givenFruitMap_whenReplacingOldValue_thenNewValueSet() {
double newPrice = 3.22;
Double applePrice = fruitMap.get("apple");
Double oldValue = fruitMap.replace("apple", newPrice);
Assertions.assertNotNull(oldValue);
Assertions.assertEquals(oldValue, applePrice);
Assertions.assertEquals(Double.valueOf(newPrice), fruitMap.get("apple"));
}
@Test
public void givenFruitMap_whenReplacingWithRealOldValue_thenNewValueSet() {
double newPrice = 3.22;
Double applePrice = fruitMap.get("apple");
boolean isUpdated = fruitMap.replace("apple", applePrice, newPrice);
Assertions.assertTrue(isUpdated);
}
@Test
public void givenFruitMap_whenReplacingWithWrongOldValue_thenNewValueNotSet() {
double newPrice = 3.22;
boolean isUpdated = fruitMap.replace("apple", Double.valueOf(0), newPrice);
Assertions.assertFalse(isUpdated);
}
@Test
public void givenFruitMap_whenGetOrDefaultUsedWithPut_thenNewEntriesAdded() {
fruitMap.put("plum", fruitMap.getOrDefault("plum", 2.41));
Assertions.assertTrue(fruitMap.containsKey("plum"));
Assertions.assertEquals(Double.valueOf(2.41), fruitMap.get("plum"));
}
@Test
public void givenFruitMap_whenPutIfAbsentUsed_thenNewEntriesAdded() {
double newValue = 1.78;
fruitMap.putIfAbsent("apple", newValue);
fruitMap.putIfAbsent("pear", newValue);
Assertions.assertTrue(fruitMap.containsKey("pear"));
Assertions.assertNotEquals(Double.valueOf(newValue), fruitMap.get("apple"));
Assertions.assertEquals(Double.valueOf(newValue), fruitMap.get("pear"));
}
@Test
public void givenFruitMap_whenComputeUsed_thenValueUpdated() {
double oldPrice = fruitMap.get("apple");
BiFunction<Double, Integer, Double> powFunction = (x1, x2) -> Math.pow(x1, x2);
fruitMap.compute(
"apple", (k, v) -> powFunction.apply(v, 2));
Assertions.assertEquals(
Double.valueOf(Math.pow(oldPrice, 2)), fruitMap.get("apple"));
Assertions.assertThrows(
NullPointerException.class, () -> fruitMap.compute("blueberry", (k, v) -> powFunction.apply(v, 2)));
}
@Test
public void givenFruitMap_whenComputeIfAbsentUsed_thenNewEntriesAdded() {
fruitMap.computeIfAbsent(
"lemon", k -> Double.valueOf(k.length()));
Assertions.assertTrue(fruitMap.containsKey("lemon"));
Assertions.assertEquals(Double.valueOf("lemon".length()), fruitMap.get("lemon"));
}
@Test
public void givenFruitMap_whenComputeIfPresentUsed_thenValuesUpdated() {
Double oldAppleValue = fruitMap.get("apple");
BiFunction<Double, Integer, Double> powFunction = (x1, x2) -> Math.pow(x1, x2);
fruitMap.computeIfPresent(
"apple", (k, v) -> powFunction.apply(v, 2));
Assertions.assertEquals(Double.valueOf(Math.pow(oldAppleValue, 2)), fruitMap.get("apple"));
}
@Test
public void givenFruitMap_whenMergeUsed_thenNewEntriesAdded() {
double defaultValue = 1.25;
BiFunction<Double, Integer, Double> powFunction = (x1, x2) -> Math.pow(x1, x2);
fruitMap.merge(
"apple", defaultValue, (k, v) -> powFunction.apply(v, 2));
fruitMap.merge(
"strawberry", defaultValue, (k, v) -> powFunction.apply(v, 2));
Assertions.assertTrue(fruitMap.containsKey("strawberry"));
Assertions.assertEquals(Double.valueOf(defaultValue), fruitMap.get("strawberry"));
Assertions.assertEquals(Double.valueOf(Math.pow(defaultValue, 2)), fruitMap.get("apple"));
}
}