Use Expected Exception Rule

Use an @Rule instead of @Test(expected=…)

exercises/phone-number/src/example/java/PhoneNumber.java

@@ -11,15 +11,18 @@ public class PhoneNumber {
     }
 
     private String normalize(String number) {
-        if(number.length() == 11 && number.startsWith("1")) {
-            number = number.substring(1, number.length());
+        if(number.length() > 11 || number.length() < 10){
+            throw new IllegalArgumentException("Number must be 10 or 11 digits");
         }
 
-        final boolean numberIsValid = (number.length() == 10);
-
-        if(!numberIsValid) {
-            throw new IllegalArgumentException();
-        }
+        if(number.length() == 11){
+            if(number.startsWith("1")){
+                number = number.substring(1, number.length());
+            }
+            else{
+                throw new IllegalArgumentException("Can only have 11 digits if number starts with '1'");
+            }
+        } 
         
         return number;
     }

exercises/phone-number/src/test/java/PhoneNumberTest.java

@@ -1,10 +1,14 @@
 import org.junit.Test;
 import org.junit.Ignore;
+import org.junit.Rule;
+import org.junit.rules.ExpectedException;
 
 import static org.junit.Assert.*;
 
 public class PhoneNumberTest {
 
+    @Rule
+    public ExpectedException expectedException = ExpectedException.none();
 
     @Test
     public void cleansNumber() {
@@ -39,15 +43,19 @@ public class PhoneNumberTest {
     }
 
     @Ignore
-    @Test(expected = IllegalArgumentException.class)
+    @Test
     public void invalidWhenOnly11Digits() {
-        final String actualNumber = new PhoneNumber("21234567890").getNumber();
+        expectedException.expect(IllegalArgumentException.class);
+        expectedException.expectMessage("Can only have 11 digits if number starts with '1'");
+        new PhoneNumber("21234567890").getNumber();
     }
 
     @Ignore
-    @Test(expected = IllegalArgumentException.class)
+    @Test
     public void invalidWhen9Digits() {
-        final String actualNumber = new PhoneNumber("123456789").getNumber();
+        expectedException.expect(IllegalArgumentException.class);
+        expectedException.expectMessage("Number must be 10 or 11 digits");
+        new PhoneNumber("123456789").getNumber();
     }
 
     @Ignore