118 lines
3.7 KiB
Java
118 lines
3.7 KiB
Java
package com.baeldung.fj;
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import static org.junit.Assert.assertEquals;
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import static org.junit.Assert.assertFalse;
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import static org.junit.Assert.assertTrue;
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import org.junit.Assert;
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import org.junit.Test;
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import fj.F;
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import fj.Show;
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import fj.data.Array;
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import fj.data.List;
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import fj.data.Option;
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import fj.function.Characters;
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import fj.function.Integers;
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public class FunctionalJavaUnitTest {
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public static final F<Integer, Boolean> isEven = i -> i % 2 == 0;
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public static final Integer timesTwoRegular(Integer i) {
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return i * 2;
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}
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public static final F<Integer, Integer> timesTwo = i -> i * 2;
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public static final F<Integer, Integer> plusOne = i -> i + 1;
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@Test
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public void multiplyNumbers_givenIntList_returnTrue() {
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List<Integer> fList = List.list(1, 2, 3, 4);
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List<Integer> fList1 = fList.map(timesTwo);
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List<Integer> fList2 = fList.map(i -> i * 2);
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assertTrue(fList1.equals(fList2));
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}
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@Test
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public void applyMultipleFunctions_givenIntList_returnFalse() {
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List<Integer> fList = List.list(1, 2, 3, 4);
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List<Integer> fList1 = fList.map(timesTwo).map(plusOne);
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Show.listShow(Show.intShow).println(fList1);
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List<Integer> fList2 = fList.map(plusOne).map(timesTwo);
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Show.listShow(Show.intShow).println(fList2);
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assertFalse(fList1.equals(fList2));
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}
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@Test
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public void calculateEvenNumbers_givenIntList_returnTrue() {
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List<Integer> fList = List.list(3, 4, 5, 6);
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List<Boolean> evenList = fList.map(isEven);
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List<Boolean> evenListTrueResult = List.list(false, true, false, true);
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assertTrue(evenList.equals(evenListTrueResult));
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}
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@Test
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public void mapList_givenIntList_returnResult() {
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List<Integer> fList = List.list(3, 4, 5, 6);
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fList = fList.map(i -> i + 100);
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List<Integer> resultList = List.list(103, 104, 105, 106);
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assertTrue(fList.equals(resultList));
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}
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@Test
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public void filterList_givenIntList_returnResult() {
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Array<Integer> array = Array.array(3, 4, 5, 6);
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Array<Integer> filteredArray = array.filter(isEven);
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Array<Integer> result = Array.array(4, 6);
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assertTrue(filteredArray.equals(result));
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}
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@Test
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public void checkForLowerCase_givenStringArray_returnResult() {
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Array<String> array = Array.array("Welcome", "To", "baeldung");
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assertTrue(array.exists(s -> List.fromString(s).forall(Characters.isLowerCase)));
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Array<String> array2 = Array.array("Welcome", "To", "Baeldung");
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assertFalse(array2.exists(s -> List.fromString(s).forall(Characters.isLowerCase)));
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assertFalse(array.forall(s -> List.fromString(s).forall(Characters.isLowerCase)));
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}
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@Test
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public void checkOptions_givenOptions_returnResult() {
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Option<Integer> n1 = Option.some(1);
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Option<Integer> n2 = Option.some(2);
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Option<Integer> n3 = Option.none();
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F<Integer, Option<Integer>> function = i -> i % 2 == 0 ? Option.some(i + 100) : Option.none();
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Option<Integer> result1 = n1.bind(function);
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Option<Integer> result2 = n2.bind(function);
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Option<Integer> result3 = n3.bind(function);
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Assert.assertEquals(Option.none(), result1);
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Assert.assertEquals(Option.some(102), result2);
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Assert.assertEquals(Option.none(), result3);
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}
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@Test
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public void foldLeft_givenArray_returnResult() {
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Array<Integer> intArray = Array.array(17, 44, 67, 2, 22, 80, 1, 27);
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int sumAll = intArray.foldLeft(Integers.add, 0);
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assertEquals(260, sumAll);
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int sumEven = intArray.filter(isEven).foldLeft(Integers.add, 0);
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assertEquals(148, sumEven);
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}
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}
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