Merge pull request #258 from colin-mullikin/phone-number-exceptions

Phone number exceptions

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

     }
 
     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);
-        final String normalizedNumber = numberIsValid ? number : "0000000000";
-        return normalizedNumber;
+        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;
     }
 
     public String getNumber() {

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

 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() {
     @Ignore
     @Test
     public void invalidWhenOnly11Digits() {
-        final String expectedNumber = "0000000000";
-        final String actualNumber = new PhoneNumber("21234567890").getNumber();
-
-        assertEquals(
-            expectedNumber, actualNumber
-        );
+        expectedException.expect(IllegalArgumentException.class);
+        expectedException.expectMessage("Can only have 11 digits if number starts with '1'");
+        new PhoneNumber("21234567890").getNumber();
     }
 
     @Ignore
     @Test
     public void invalidWhen9Digits() {
-        final String expectedNumber = "0000000000";
-        final String actualNumber = new PhoneNumber("123456789").getNumber();
-
-        assertEquals(
-            expectedNumber, actualNumber
-        );
+        expectedException.expect(IllegalArgumentException.class);
+        expectedException.expectMessage("Number must be 10 or 11 digits");
+        new PhoneNumber("123456789").getNumber();
     }
 
     @Ignore