Fix(14) - Null exception

.gitignore

@@ -3,3 +3,4 @@ build
 *.iws
 *.iml
 .gradle
+out/

src/main/java/emailvalidator4j/parser/Email.java

@@ -7,8 +7,10 @@
 import emailvalidator4j.parser.exception.InvalidEmail;
 import emailvalidator4j.parser.exception.NoLocalPart;
 
+import javax.swing.text.html.Option;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 
 public class Email {
     private final EmailLexer lexer;
@@ -22,7 +24,9 @@ public Email(EmailLexer lexer) {
     }
 
     public void parse(String email) throws InvalidEmail {
-        this.lexer.lex(email);
+        this.lexer.lex(Optional.ofNullable(email).orElseThrow(() ->
+            new InvalidEmail("Empty email")
+        ));
 
         if (!this.lexer.find(Tokens.AT)) {
             throw new NoLocalPart("No local part found");

src/test/java/emailvalidator4j/EmailValidatorTest.java

@@ -111,6 +111,12 @@ public void validEmailHasNoWarnings() {
         Assert.assertFalse(validator.hasWarnings());
     }
 
+    @Test
+    public void preventNull() {
+        EmailValidator validator = new EmailValidator();
+        Assert.assertFalse(validator.isValid(null));
+    }
+
     @Test
     public void validEmailHasWarnings() {
         EmailValidator validator = new EmailValidator();