refactor: use AssertJ for testing

Majority of our test cases use AssertJ

src/test/java/org/owasp/webgoat/lessons/challenges/challenge7/MD5Test.java

@@ -23,8 +23,7 @@
 
 package org.owasp.webgoat.lessons.challenges.challenge7;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.assertj.core.api.Assertions.assertThat;
-
 import java.util.stream.Stream;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -37,7 +36,7 @@ public class MD5Test {
   @DisplayName("MD5 test")
   @MethodSource("providedForMD5Values")
   void testMD5(String in, String out) {
-    assertEquals(MD5.getHashString(in.getBytes()), out);
+    assertThat(out).isEqualTo(MD5.getHashString(in.getBytes()));
   }
 
   private static Stream<Arguments> providedForMD5Values() {

src/test/java/org/owasp/webgoat/lessons/cryptography/CryptoUtilTest.java

@@ -1,7 +1,7 @@
 package org.owasp.webgoat.lessons.cryptography;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.assertj.core.api.Assertions.fail;
 
 import java.security.KeyPair;
 import java.security.PrivateKey;
@@ -23,11 +23,9 @@ public class CryptoUtilTest {
       String modulus = DatatypeConverter.printHexBinary(rsaPubKey.getModulus().toByteArray());
       String signature = CryptoUtil.signMessage(modulus, privateKey);
       log.debug("public exponent {}", rsaPubKey.getPublicExponent());
-      assertTrue(CryptoUtil.verifyAssignment(modulus, signature, keyPair.getPublic()));
+      assertThat(CryptoUtil.verifyAssignment(modulus, signature, keyPair.getPublic())).isTrue();
     } catch (Exception e) {
-      log.error("signing failed", e);
+      fail("Signing failed");
-      ;
-      fail();
     }
   }
 }

src/test/java/org/owasp/webgoat/lessons/spoofcookie/encoders/EncDecTest.java

@@ -22,11 +22,9 @@
 
 package org.owasp.webgoat.lessons.spoofcookie.encoders;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.jupiter.api.Assertions.assertNull;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 import java.util.stream.Stream;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -48,7 +46,7 @@ class EncDecTest {
   void testEncode(String decoded, String encoded) {
     String result = EncDec.encode(decoded);
 
-    assertTrue(result.endsWith(encoded));
+    assertThat(result.endsWith(encoded)).isTrue();
   }
 
   @ParameterizedTest
@@ -63,13 +61,13 @@ class EncDecTest {
   @Test
   @DisplayName("null encode test")
   void testNullEncode() {
-    assertNull(EncDec.encode(null));
+    assertThat(EncDec.encode(null)).isNull();
   }
 
   @Test
   @DisplayName("null decode test")
   void testNullDecode() {
-    assertNull(EncDec.decode(null));
+    assertThat(EncDec.decode(null)).isNull();
   }
 
   private static Stream<Arguments> providedForEncValues() {

src/test/java/org/owasp/webgoat/lessons/vulnerablecomponents/VulnerableComponentsLessonTest.java

@@ -22,10 +22,8 @@
 
 package org.owasp.webgoat.lessons.vulnerablecomponents;
 
-import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 import com.thoughtworks.xstream.XStream;
 import com.thoughtworks.xstream.io.StreamException;
 import org.junit.jupiter.api.Disabled;
@@ -53,7 +51,7 @@ public class VulnerableComponentsLessonTest {
     xstream.setClassLoader(Contact.class.getClassLoader());
     xstream.alias("contact", ContactImpl.class);
     xstream.ignoreUnknownElements();
-    assertNotNull(xstream.fromXML(contact));
+    assertThat(xstream.fromXML(contact)).isNotNull();
   }
 
   @Test
@@ -67,7 +65,7 @@ public class VulnerableComponentsLessonTest {
         assertThrows(
             RuntimeException.class,
             () -> ((Contact) xstream.fromXML(strangeContact)).getFirstName());
-    assertTrue(e.getCause().getMessage().contains("calc.exe"));
+    assertThat(e.getCause().getMessage().contains("calc.exe")).isTrue();
   }
 
   @Test
@@ -79,6 +77,6 @@ public class VulnerableComponentsLessonTest {
     Exception e =
         assertThrows(
             StreamException.class, () -> ((Contact) xstream.fromXML("bullssjfs")).getFirstName());
-    assertTrue(e.getCause().getMessage().contains("START_DOCUMENT"));
+    assertThat(e.getCause().getMessage().contains("START_DOCUMENT")).isTrue();
   }
 }

src/test/java/org/owasp/webgoat/webwolf/mailbox/MailboxRepositoryTest.java

@@ -22,8 +22,7 @@
 
 package org.owasp.webgoat.webwolf.mailbox;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.assertj.core.api.Assertions.assertThat;
-
 import java.time.LocalDateTime;
 import java.util.List;
 import org.junit.jupiter.api.Test;
@@ -58,6 +57,6 @@ public class MailboxRepositoryTest {
 
     List<Email> emails = mailboxRepository.findByRecipientOrderByTimeDesc("someone@webwolf.org");
 
-    assertEquals(emails.size(), 1);
+    assertThat(emails.size()).isEqualTo(1);
   }
 }

src/test/java/org/owasp/webgoat/webwolf/user/UserServiceTest.java

@@ -22,7 +22,7 @@
 
 package org.owasp.webgoat.webwolf.user;
 
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThatExceptionOfType;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -62,7 +62,7 @@ public class UserServiceTest {
 
     when(mockUserRepository.findByUsername(username)).thenReturn(null);
 
-    assertThrows(UsernameNotFoundException.class, () -> sut.loadUserByUsername(username));
+    assertThatExceptionOfType(UsernameNotFoundException.class).isThrownBy(() -> sut.loadUserByUsername(username));
   }
 
   @Test