If string is empty return empty string instead of null

Verify that passing in an empty string does not return null

Handling cases where the url could be malformed so there are no hosts even with a non-empty string

WordPressUtils/src/androidTest/java/org/wordpress/android/util/UrlUtilsTest.java

@@ -0,0 +1,20 @@
+package org.wordpress.android.util;
+
+import android.test.InstrumentationTestCase;
+
+public class UrlUtilsTest extends InstrumentationTestCase {
+    public void testGetDomainFromUrlWithEmptyStringDoesNotReturnNull() {
+        assertNotNull(UrlUtils.getDomainFromUrl(""));
+    }
+
+    public void testGetDomainFromUrlWithNoHostDoesNotReturnNull() {
+        assertNotNull(UrlUtils.getDomainFromUrl("wordpress"));
+    }
+
+    public void testGetDomainFromUrlWithHostReturnsHost() {
+        String url = "http://www.wordpress.com";
+        String host = UrlUtils.getDomainFromUrl(url);
+
+        assertTrue(host.equals("www.wordpress.com"));
+    }
+}

WordPressUtils/src/main/java/org/wordpress/android/util/UrlUtils.java

@@ -33,11 +33,14 @@ public static String urlDecode(final String text) {
     }
 
     public static String getDomainFromUrl(final String urlString) {
-        if (urlString == null) {
-            return "";
+        if (urlString != null) {
+            Uri uri = Uri.parse(urlString);
+            if (uri.getHost() != null) {
+                return uri.getHost();
+            }
         }
-        Uri uri = Uri.parse(urlString);
-        return uri.getHost();
+
+        return "";
     }
 
     /**