BAEL-580 handling exceptions in lambda expressions (#1004)

core-java/src/test/java/com/baeldung/java8/lambda/exceptions/LambdaExceptionWrappersTest.java

@@ -0,0 +1,46 @@
+package com.baeldung.java8.lambda.exceptions;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static com.baeldung.java8.lambda.exceptions.LambdaExceptionWrappers.*;
+
+public class LambdaExceptionWrappersTest {
+
+    private List<Integer> integers;
+
+    @Before
+    public void init() {
+        integers = Arrays.asList(3, 9, 7, 0, 10, 20);
+    }
+
+    @Test
+    public void whenNoExceptionFromLambdaWrapper_thenSuccess() {
+        integers.forEach(lambdaWrapper(i -> System.out.println(50 / i)));
+    }
+
+    @Test
+    public void whenNoExceptionFromConsumerWrapper_thenSuccess() {
+        integers.forEach(consumerWrapper(i -> System.out.println(50 / i), ArithmeticException.class));
+    }
+
+    @Test(expected = RuntimeException.class)
+    public void whenExceptionFromThrowingConsumerWrapper_thenSuccess() {
+        integers.forEach(throwingConsumerWrapper(i -> writeToFile(i)));
+    }
+
+    @Test
+    public void whenNoExceptionFromHandlingConsumerWrapper_thenSuccess() {
+        integers.forEach(handlingConsumerWrapper(i -> writeToFile(i), IOException.class));
+    }
+
+    void writeToFile(Integer i) throws IOException {
+        if (i == 0) {
+            throw new IOException(); // mock IOException
+        }
+    }
+}