Added BiFunction examples

Author: fdpro

src/main/java/com/fdpro/trainings/functionaljava/BiFunctionExamples.java

@@ -0,0 +1,10 @@
+package com.fdpro.trainings.functionaljava;
+
+import java.util.function.BiFunction;
+
+public class BiFunctionExamples {
+
+    public static <T> T getInfo(Person personA, Person personB, BiFunction<Person, Person, T> infoCollector) {
+        return infoCollector.apply(personA, personB);
+    }
+}

src/test/java/com/fdpro/trainings/functionaljava/BiFunctionExamplesTest.java

@@ -0,0 +1,37 @@
+package com.fdpro.trainings.functionaljava;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.function.BiFunction;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class BiFunctionExamplesTest {
+
+    private Person robert;
+    private Person anna;
+
+    @BeforeEach
+    void initPeople() {
+        robert = new Person("Robert", 50);
+        anna = new Person("Anna", 43);
+    }
+
+    @Test
+    void getInfo_MaxAge() {
+        BiFunction<Person, Person, Integer> getMaxAge = (p1, p2) -> Math.max(p1.getAge(), p2.getAge());
+
+        Integer maxAge = BiFunctionExamples.getInfo(robert, anna, getMaxAge);
+        assertThat(maxAge).isEqualTo(50);
+    }
+
+    @Test
+    void getInfo_PersonWithSmallestName() {
+        BiFunction<Person, Person, Person> getPersonWithSmallestName = (p1, p2) -> p1.getName().length() <= p2.getName().length() ? p1 : p2;
+
+        Person personWithSmallestName = BiFunctionExamples.getInfo(robert, anna, getPersonWithSmallestName);
+        assertThat(personWithSmallestName).isEqualTo(anna);
+    }
+
+}