refactor isInWordlist test and implementation

src/main/java/PasswordValidator.java

@@ -4,6 +4,7 @@ import java.io.StringReader;
 import java.math.BigInteger;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.Locale;
 import java.util.regex.Pattern;
 
 public class PasswordValidator {
@@ -135,12 +136,13 @@ public class PasswordValidator {
 
     public static boolean isInWordlist(String password) {
         try {
+            String lowerPassword = password.toLowerCase();
             ResourceApi resourceApi = new ResourceApi();
             String germanWordlist = resourceApi.getFileFromResourceAsString("german_wordlist.txt");
             BufferedReader bufReader = new BufferedReader(new StringReader(germanWordlist));
             String line = null;
             while ((line = bufReader.readLine()) != null) {
-                if (line.contains(password)) {
+                if (lowerPassword.contains(line.trim().toLowerCase())) {
                     return true;
                 }
             }

src/test/java/PasswordValidatorTest.java

@@ -92,7 +92,8 @@ class PasswordValidatorTest {
 
     @Test
     void isInWordlist() {
-        assertTrue(PasswordValidator.isInWordlist("Sonne"));
+        assertTrue(PasswordValidator.isInWordlist("Sonnenblume"));
+        assertTrue(PasswordValidator.isInWordlist("_Sonnenblume123"));
         assertFalse(PasswordValidator.isInWordlist("=phan0johB4aisae6Mie0jeip9Saejahc0iuvuth7ahv9uoni6o*_.+"));
     }
 }