updates slides for lecture 7

lectures/revealjs/07-lecture.adoc

@@ -217,11 +217,29 @@ public class FoobarTest {
 
 |===
 
+== Expecting exceptions (1)
+
+``` java
+@Test
+void testAssertingExpectedException() {
+	Assertions.assertThrows(<ExpectedException.class>, () -> {
+	    <code expected to throw exception>;
+		});
+}
+```
+
+== Expecting exceptions (2)
+
+- if the code throws
+** the exception class that is expected the the test will PASS
+** a descendent class exception that is expected the the test will PASS
+** a different exception type the test will FAIL
+** throws no exception the test will FAIL
+
 
 [background-color = "#124990"]
 [color = "#fff6d5"]
 == Testing in todo-list example
 
 
-
 include::{includedir}footer.adoc[]
\ No newline at end of file