fix: Handle specific exceptions while email verification

src/main/java/amu/zhcet/auth/verification/DuplicateEmailException.java

@@ -1,9 +1,17 @@
 package amu.zhcet.auth.verification;
 
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+@Data
+@EqualsAndHashCode(callSuper = false)
 public class DuplicateEmailException extends RuntimeException {
 
+    private String email;
+
     public DuplicateEmailException(String email) {
         super("'" + email + "' is already registered by another user");
+        this.email = email;
     }
 
 }

src/main/java/amu/zhcet/auth/verification/EmailVerificationController.java

@@ -33,9 +33,13 @@ private void sendVerificationLink(String email, RedirectAttributes redirectAttri
         } catch (DuplicateEmailException de) {
             log.warn("Duplicate Email", de);
             redirectAttributes.addFlashAttribute("email_error", de.getMessage());
+        } catch (RecentVerificationException re) {
+            log.warn("Recently Sent Email", re);
+            redirectAttributes.addFlashAttribute("email_error", RecentVerificationException.MESSAGE);
         } catch (RuntimeException re) {
             log.warn("Error sending verification link", re);
-            redirectAttributes.addFlashAttribute("email_error", re.getMessage());
+            redirectAttributes.addFlashAttribute("email_error",
+                    "There was some error sending the email");
         }
     }
 
@@ -77,9 +81,9 @@ public String verifyEmail(Model model, @RequestParam("auth") String token) {
         try {
             emailVerificationService.verifyEmail(token);
             model.addAttribute("success", "Your email was successfully verified!");
-        } catch (IllegalStateException | DuplicateEmailException ie) {
-            log.warn("Email Verification Error {}", ie.getMessage());
-            model.addAttribute("error", ie.getMessage());
+        } catch (DuplicateEmailException | TokenVerificationException de) {
+            log.warn("Email Verification Error {}", de.getMessage());
+            model.addAttribute("error", de.getMessage());
         }
 
         return "user/verify_email";

src/main/java/amu/zhcet/auth/verification/EmailVerificationService.java

@@ -9,6 +9,7 @@
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.mail.MailException;
 import org.springframework.stereotype.Service;
 
 import javax.transaction.Transactional;
@@ -45,8 +46,9 @@ public EmailVerificationService(UserService userService, LinkMailService linkMai
     private VerificationToken createVerificationToken(String email) {
         User user = userService.getLoggedInUser().orElseThrow(() -> new IllegalStateException("No user logged in"));
         // Check if link was already sent
-        if (emailCache.getIfPresent(user.getUserId()) != null)
-            throw new RuntimeException("Verification link was recently sent. Please wait for some time");
+        LocalDateTime sentTime = emailCache.getIfPresent(user.getUserId());
+        if (sentTime != null)
+            throw new RecentVerificationException(sentTime);
 
         emailCache.put(user.getUserId(), LocalDateTime.now());
 
@@ -101,22 +103,22 @@ public void generate(String email) {
     /**
      * Retrieves the verification token from database and validates it by performing checks
      * that it exists, is not already used and not expired. If any of the validation fails,
-     * throws an {@link IllegalStateException} with the corresponding message
+     * throws an {@link TokenVerificationException} with the corresponding message
      * @param token String token ID
      * @return {@link VerificationToken}
      */
     private VerificationToken getAndValidateOrThrow(String token) {
         VerificationToken verificationToken = verificationTokenRepository.findByToken(token);
 
         if (verificationToken == null)
-            throw new IllegalStateException("Token: " + token + " is invalid");
+            throw new TokenVerificationException("Token: " + token + " is invalid");
 
         if (verificationToken.isUsed())
-            throw new IllegalStateException("Token: " + token + " is already used! Please request another link!");
+            throw new TokenVerificationException("Token: " + token + " is already used! Please request another link!");
 
         Calendar cal = Calendar.getInstance();
         if ((verificationToken.getExpiry().getTime() - cal.getTime().getTime()) <= 0)
-            throw new IllegalStateException("Token: " + token + " has expired");
+            throw new TokenVerificationException("Token: " + token + " has expired");
 
         return verificationToken;
     }
@@ -186,17 +188,25 @@ public void sendMail(VerificationToken token) {
         String relativeUrl = "/login/email/verify?auth=" + token.getToken();
         log.debug("Verification link generated : {}", relativeUrl);
 
-        linkMailService.sendEmail(getPayLoad(token.getEmail(), token.getUser(), relativeUrl), false);
-
-        // Now we set the email to the user and disable email verified
-        User user = token.getUser();
-        log.debug("Saving user email {} -> {}", user.getUserId(), token.getEmail());
-        user.setEmail(token.getEmail());
-        user.setEmailVerified(false);
-
-        userService.save(user);
-        log.debug("Saved user email");
-        eventPublisher.publishEvent(new EmailVerifiedEvent(user));
+        try {
+            linkMailService.sendEmail(getPayLoad(token.getEmail(), token.getUser(), relativeUrl), false);
+            // Now we set the email to the user and disable email verified
+            User user = token.getUser();
+            log.debug("Saving user email {} -> {}", user.getUserId(), token.getEmail());
+            user.setEmail(token.getEmail());
+            user.setEmailVerified(false);
+
+            userService.save(user);
+            log.debug("Saved user email");
+            eventPublisher.publishEvent(new EmailVerifiedEvent(user));
+        } catch (MailException mailException) {
+            // There was an error sending the mail, so remove the token and sent time
+            verificationTokenRepository.delete(token);
+            emailCache.invalidate(token.getUser().getUserId());
+            log.warn("Email sending for {} '{}' failed, so we removed the verification token",
+                    token.getUser(), token.getEmail(), mailException);
+            throw mailException;
+        }
     }
 
 }

src/main/java/amu/zhcet/auth/verification/RecentVerificationException.java

@@ -0,0 +1,29 @@
+package amu.zhcet.auth.verification;
+
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import org.springframework.lang.Nullable;
+
+import java.time.LocalDateTime;
+
+@Data
+@EqualsAndHashCode(callSuper = false)
+public class RecentVerificationException extends RuntimeException {
+
+    public static final String MESSAGE = "Verification link was recently sent. Please wait for some time";
+
+    @Nullable
+    private LocalDateTime sentTime;
+
+    public RecentVerificationException() {
+        super(MESSAGE);
+    }
+
+    public RecentVerificationException(LocalDateTime sentTime) {
+        super(String.format(
+                "Verification link was recently sent at %s. Please wait for some time",
+                sentTime.toString()));
+        this.sentTime = sentTime;
+    }
+
+}

src/main/java/amu/zhcet/auth/verification/TokenVerificationException.java

@@ -0,0 +1,9 @@
+package amu.zhcet.auth.verification;
+
+public class TokenVerificationException extends IllegalStateException {
+
+    public TokenVerificationException(String message) {
+        super(message);
+    }
+
+}

src/test/java/amu/zhcet/auth/verification/DuplicateEmailExceptionTest.java

@@ -0,0 +1,29 @@
+package amu.zhcet.auth.verification;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class DuplicateEmailExceptionTest {
+
+    private DuplicateEmailException duplicateEmailException;
+
+    @Before
+    public void setUp() {
+        duplicateEmailException = new DuplicateEmailException("[email protected]");
+    }
+
+    @Test
+    public void testConstructorMessage() {
+        assertEquals(
+                "'[email protected]' is already registered by another user",
+                duplicateEmailException.getMessage());
+    }
+
+    @Test
+    public void testGettingEmail() {
+        assertEquals("[email protected]", duplicateEmailException.getEmail());
+    }
+
+}

src/test/java/amu/zhcet/auth/verification/RecentVerificationExceptionTest.java

@@ -0,0 +1,35 @@
+package amu.zhcet.auth.verification;
+
+import org.junit.Test;
+
+import java.time.LocalDateTime;
+
+import static org.junit.Assert.*;
+
+public class RecentVerificationExceptionTest {
+
+    private LocalDateTime localDateTime = LocalDateTime.of(2018, 9, 1, 12, 23);
+
+    @Test
+    public void testNoConstructorMessage() {
+        RecentVerificationException recentVerificationException = new RecentVerificationException();
+        assertEquals(
+                "Verification link was recently sent. Please wait for some time",
+                recentVerificationException.getMessage());
+    }
+
+    @Test
+    public void testConstructorMessage() {
+        RecentVerificationException recentVerificationException = new RecentVerificationException(localDateTime);
+        assertEquals(
+                "Verification link was recently sent at 2018-09-01T12:23. Please wait for some time",
+                recentVerificationException.getMessage());
+    }
+
+    @Test
+    public void testGettingSentTime() {
+        RecentVerificationException recentVerificationException = new RecentVerificationException(localDateTime);
+        assertEquals(localDateTime, recentVerificationException.getSentTime());
+    }
+
+}