add tests

src/test/java/org/subethamail/smtp/PlainAuthenticationHandlerFactoryTest.java

@@ -0,0 +1,31 @@
+package org.subethamail.smtp;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.mockito.Mockito;
+import org.subethamail.smtp.auth.LoginFailedException;
+import org.subethamail.smtp.auth.PlainAuthenticationHandlerFactory;
+import org.subethamail.smtp.auth.UsernamePasswordValidator;
+
+public class PlainAuthenticationHandlerFactoryTest {
+
+    @Test
+    public void test() throws RejectException {
+        MessageContext context = Mockito.mock(MessageContext.class);
+        UsernamePasswordValidator validator = (username, password, c) -> {
+            if (!username.equals("fred") || !password.equals("blah")) {
+                throw new LoginFailedException();
+            }
+        };
+        AuthenticationHandler auth = new PlainAuthenticationHandlerFactory(validator).create();
+        try {
+            auth.auth("AUTH PLAIN b", context);
+            Assert.fail();
+        } catch (RejectException e) {
+            assertEquals("Invalid command argument, not a valid Base64 string", e.getMessage());
+        }
+    }
+
+}

src/test/java/org/subethamail/smtp/command/AuthTest.java

@@ -243,4 +243,5 @@ public void testBadPass() throws Exception {
         send("bad-password");
         expect("501");
     }
+
 }