[BAEL-16669] moved testing-modules/testing modules into relevant folders

assertion-libraries/src/test/java/com/baeldung/assertj/exceptions/Java8StyleAssertions.java

@@ -0,0 +1,66 @@
+package com.baeldung.assertj.exceptions;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.catchThrowable;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import org.junit.Test;
+
+public class Java8StyleAssertions {
+
+    @Test
+    public void whenGettingOutOfBoundsItem_thenIndexOutOfBoundsException() {
+        assertThatThrownBy(() -> {
+            ArrayList<String> myStringList = new ArrayList<String>(Arrays.asList("Strine one", "String two"));
+            myStringList.get(2);
+        }).isInstanceOf(IndexOutOfBoundsException.class)
+            .hasMessageStartingWith("Index: 2")
+            .hasMessageContaining("2")
+            .hasMessageEndingWith("Size: 2")
+            .hasMessageContaining("Index: 2, Size: 2")
+            .hasMessage("Index: %s, Size: %s", 2, 2)
+            .hasMessageMatching("Index: \\d+, Size: \\d+")
+            .hasNoCause();
+    }
+
+    @Test
+    public void whenWrappingException_thenCauseInstanceOfWrappedExceptionType() {
+        assertThatThrownBy(() -> {
+            try {
+                throw new IOException();
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }).isInstanceOf(RuntimeException.class)
+            .hasCauseInstanceOf(IOException.class)
+            .hasStackTraceContaining("IOException");
+    }
+
+    @Test
+    public void whenDividingByZero_thenArithmeticException() {
+        assertThatExceptionOfType(ArithmeticException.class).isThrownBy(() -> {
+            int numerator = 10;
+            int denominator = 0;
+            int quotient = numerator / denominator;
+        })
+            .withMessageContaining("/ by zero");
+
+        // Alternatively:
+
+        // when
+        Throwable thrown = catchThrowable(() -> {
+            int numerator = 10;
+            int denominator = 0;
+            int quotient = numerator / denominator;
+        });
+
+        // then
+        assertThat(thrown).isInstanceOf(ArithmeticException.class)
+            .hasMessageContaining("/ by zero");
+
+    }
+}