Enhanced validation taking base into account for batch send, added unit-tests with base

Author: vitalii-t

src/main/java/io/mailtrap/api/apiresource/SendApiResource.java

@@ -3,6 +3,11 @@
 import io.mailtrap.CustomValidator;
 import io.mailtrap.config.MailtrapConfig;
 import io.mailtrap.exception.InvalidRequestBodyException;
+import io.mailtrap.model.mailvalidation.ContentView;
+import io.mailtrap.model.mailvalidation.MailContentView;
+import io.mailtrap.model.mailvalidation.ResolvedMailContentView;
+import io.mailtrap.model.mailvalidation.ResolvedMailView;
+import io.mailtrap.model.request.emails.BatchEmailBase;
 import io.mailtrap.model.request.emails.MailtrapBatchMail;
 import io.mailtrap.model.request.emails.MailtrapMail;
 import org.apache.commons.collections4.MapUtils;
@@ -19,74 +24,93 @@ protected SendApiResource(MailtrapConfig config, CustomValidator customValidator
         super(config, customValidator);
     }
 
-    protected void assertBatchMailNotNull(MailtrapBatchMail batchMail) {
-        if (batchMail == null) {
-            throw new InvalidRequestBodyException("BatchMail must not be null");
-        }
-        if (batchMail.getRequests() == null || batchMail.getRequests().isEmpty()) {
-            throw new InvalidRequestBodyException("BatchMail.requests must not be null or empty");
-        }
-        if (batchMail.getRequests().stream().anyMatch(Objects::isNull)) {
-            throw new InvalidRequestBodyException("BatchMail.requests must not contain null items");
-        }
-    }
-
     /**
      * Validates the request body of an email message and throws an exception if it is invalid.
      *
      * @param mail The email message to be validated.
      * @throws InvalidRequestBodyException If the request body is invalid.
      */
-    protected void validateMailPayload(MailtrapMail mail) throws InvalidRequestBodyException {
-        // Check if the mail object itself is null
+    protected void validateMailPayload(MailtrapMail mail) {
         if (mail == null) {
             throw new InvalidRequestBodyException("Mail must not be null");
         }
 
-        // Check if all three subject, text, and html are empty
-        boolean isSubjectTextHtmlEmpty = StringUtils.isBlank(mail.getSubject())
-            && StringUtils.isBlank(mail.getText())
-            && StringUtils.isBlank(mail.getHtml());
-
-        // Validate depending on whether the templateUuid is set
-        if (StringUtils.isEmpty(mail.getTemplateUuid())) {
-            // Validation for the scenario where templateUuid is not provided
-            validateWithoutTemplate(mail, isSubjectTextHtmlEmpty);
-        } else {
-            // Validation for the scenario where templateUuid is provided
-            validateWithTemplate(mail);
-        }
-
-        // Additional validation logic (assumed to be provided by the user)
+        // Perform bean validation (NotNull, etc.)
         validateRequestBodyAndThrowException(mail);
+
+        // Validate subject/text/html/templateUuid
+        validateContentRules(MailContentView.of(mail));
     }
 
-    private void validateWithoutTemplate(MailtrapMail mail, boolean isSubjectTextHtmlEmpty) throws InvalidRequestBodyException {
-        // Ensure that at least subject, text, or html is provided if templateUuid is not set
-        if (isSubjectTextHtmlEmpty) {
-            throw new InvalidRequestBodyException("Mail must have subject and either text or html when templateUuid is not provided");
-        }
+    /**
+     * Validates the request body of batch email and throws an exception if it is invalid.
+     *
+     * @param batch batch request to be validated.
+     * @throws InvalidRequestBodyException If the request body is invalid.
+     */
+    protected void validateBatchPayload(MailtrapBatchMail batch) {
+        assertBatchMailNotNull(batch);
 
-        // Ensure templateVariables are not used if templateUuid is not set
-        if (MapUtils.isNotEmpty(mail.getTemplateVariables())) {
-            throw new InvalidRequestBodyException("Mail templateVariables must only be used with templateUuid");
-        }
+        BatchEmailBase base = batch.getBase();
+
+        for (int i = 0; i < batch.getRequests().size(); i++) {
+            MailtrapMail mail = batch.getRequests().get(i);
+            ResolvedMailView mailView = new ResolvedMailView(base, mail);
+
+            try {
+                // Perform bean validation (NotNull, etc.)
+                validateRequestBodyAndThrowException(mailView);
+            } catch (InvalidRequestBodyException e) {
+                throw new InvalidRequestBodyException("requests[" + i + "]: " + e.getMessage(), e);
+            }
+
+            validateContentRules(ResolvedMailContentView.of(mailView));
 
-        // Ensure the subject is not empty
-        if (StringUtils.isBlank(mail.getSubject())) {
-            throw new InvalidRequestBodyException("Subject must not be null or empty");
+            if (mailView.getFrom() == null) {
+                throw new InvalidRequestBodyException("requests[" + i + "]: from is required (either in mail or base)");
+            }
         }
+    }
 
-        // Ensure at least one of text or html is present
-        if (StringUtils.isBlank(mail.getText()) && StringUtils.isBlank(mail.getHtml())) {
-            throw new InvalidRequestBodyException("Mail must have subject and either text or html when templateUuid is not provided");
+    private void assertBatchMailNotNull(MailtrapBatchMail batchMail) {
+        if (batchMail == null) {
+            throw new InvalidRequestBodyException("BatchMail must not be null");
         }
+        if (batchMail.getRequests() == null || batchMail.getRequests().isEmpty()) {
+            throw new InvalidRequestBodyException("BatchMail.requests must not be null or empty");
+        }
+        if (batchMail.getRequests().stream().anyMatch(Objects::isNull)) {
+            throw new InvalidRequestBodyException("BatchMail.requests must not contain null items");
+        }
+
     }
 
-    private void validateWithTemplate(MailtrapMail mail) throws InvalidRequestBodyException {
-        // Ensure that subject, text, and html are not used when templateUuid is set
-        if (StringUtils.isNotEmpty(mail.getText()) || StringUtils.isNotEmpty(mail.getHtml()) || StringUtils.isNotEmpty(mail.getSubject())) {
-            throw new InvalidRequestBodyException("When templateUuid is used, subject, text, and html must not be used");
+    private void validateContentRules(ContentView v) {
+        boolean templateUuidBlank = StringUtils.isBlank(v.getTemplateUuid());
+
+        boolean subjectTextHtmlEmpty = StringUtils.isBlank(v.getSubject())
+            && StringUtils.isBlank(v.getText())
+            && StringUtils.isBlank(v.getHtml());
+
+        if (templateUuidBlank) {
+            if (subjectTextHtmlEmpty) {
+                throw new InvalidRequestBodyException("Mail must have subject and either text or html when templateUuid is not provided");
+            }
+            if (MapUtils.isNotEmpty(v.getTemplateVariables())) {
+                throw new InvalidRequestBodyException("Mail templateVariables must only be used with templateUuid");
+            }
+            if (StringUtils.isBlank(v.getSubject())) {
+                throw new InvalidRequestBodyException("Subject must not be null or empty");
+            }
+            if (StringUtils.isBlank(v.getText()) && StringUtils.isBlank(v.getHtml())) {
+                throw new InvalidRequestBodyException("Mail must have subject and either text or html when templateUuid is not provided");
+            }
+        } else {
+            if (StringUtils.isNotEmpty(v.getSubject())
+                || StringUtils.isNotEmpty(v.getText())
+                || StringUtils.isNotEmpty(v.getHtml()))
+                throw new InvalidRequestBodyException("When templateUuid is used, subject, text, and html must not be used");
         }
     }
+
 }

src/main/java/io/mailtrap/api/bulkemails/BulkEmailsImpl.java

@@ -34,11 +34,7 @@ public SendResponse send(MailtrapMail mail) {
 
     @Override
     public BatchSendResponse batchSend(MailtrapBatchMail mail) throws HttpException, InvalidRequestBodyException {
-        assertBatchMailNotNull(mail);
-
-        mail
-            .getRequests()
-            .forEach(this::validateMailPayload);
+        validateBatchPayload(mail);
 
         return
             httpClient.post(apiHost + "/api/batch", mail, new RequestData(), BatchSendResponse.class);

src/main/java/io/mailtrap/api/sendingemails/SendingEmailsImpl.java

@@ -34,11 +34,7 @@ public SendResponse send(MailtrapMail mail) {
 
     @Override
     public BatchSendResponse batchSend(MailtrapBatchMail mail) throws HttpException, InvalidRequestBodyException {
-        assertBatchMailNotNull(mail);
-
-        mail
-            .getRequests()
-            .forEach(this::validateMailPayload);
+        validateBatchPayload(mail);
 
         return
             httpClient.post(apiHost + "/api/batch", mail, new RequestData(), BatchSendResponse.class);

src/main/java/io/mailtrap/api/testingemails/TestingEmailsImpl.java

@@ -34,11 +34,7 @@ public SendResponse send(MailtrapMail mail, long inboxId) {
 
     @Override
     public BatchSendResponse batchSend(MailtrapBatchMail mail, long inboxId) throws HttpException, InvalidRequestBodyException {
-        assertBatchMailNotNull(mail);
-
-        mail
-            .getRequests()
-            .forEach(this::validateMailPayload);
+        validateBatchPayload(mail);
 
         return
             httpClient.post(String.format(apiHost + "/api/batch/%d", inboxId), mail, new RequestData(), BatchSendResponse.class);

src/main/java/io/mailtrap/exception/InvalidRequestBodyException.java

@@ -9,4 +9,8 @@ public InvalidRequestBodyException(String errorMessage) {
         super(errorMessage);
     }
 
+    public InvalidRequestBodyException(String errorMessage, Exception cause) {
+        super(errorMessage, cause);
+    }
+
 }

src/main/java/io/mailtrap/model/mailvalidation/ContentView.java

@@ -0,0 +1,21 @@
+package io.mailtrap.model.mailvalidation;
+
+import java.util.Map;
+
+/**
+ * An adapter used by mail content validation rules. It exposes only the fields that participate in
+ * subject/text/html/template logic so the same rules can run for both single and batch sends.
+ */
+public interface ContentView {
+
+    String getSubject();
+
+    String getText();
+
+    String getHtml();
+
+    String getTemplateUuid();
+
+    Map<String, Object> getTemplateVariables();
+
+}

src/main/java/io/mailtrap/model/mailvalidation/MailContentView.java

@@ -0,0 +1,41 @@
+package io.mailtrap.model.mailvalidation;
+
+import io.mailtrap.model.request.emails.MailtrapMail;
+
+import java.util.Map;
+
+/**
+ * ContentView implementation for a single-send MailtrapMail.
+ */
+public final class MailContentView implements ContentView {
+    private final MailtrapMail mail;
+
+    public String getSubject() {
+        return mail.getSubject();
+    }
+
+    public String getText() {
+        return mail.getText();
+    }
+
+    public String getHtml() {
+        return mail.getHtml();
+    }
+
+    public String getTemplateUuid() {
+        return mail.getTemplateUuid();
+    }
+
+    public Map<String, Object> getTemplateVariables() {
+        return mail.getTemplateVariables();
+    }
+
+    public static ContentView of(MailtrapMail content) {
+        return new MailContentView(content);
+    }
+
+    private MailContentView(MailtrapMail content) {
+        this.mail = content;
+    }
+}
+

src/main/java/io/mailtrap/model/mailvalidation/ResolvedMailContentView.java

@@ -0,0 +1,39 @@
+package io.mailtrap.model.mailvalidation;
+
+import java.util.Map;
+
+/**
+ * ContentView implementation for a batch item via ResolvedMailView. Exposes the already-resolved (item-first, base-fallback)
+ * values to the shared content rules.
+ */
+public final class ResolvedMailContentView implements ContentView {
+    private final ResolvedMailView mailView;
+
+    public String getSubject() {
+        return mailView.getSubject();
+    }
+
+    public String getText() {
+        return mailView.getText();
+    }
+
+    public String getHtml() {
+        return mailView.getHtml();
+    }
+
+    public String getTemplateUuid() {
+        return mailView.getTemplateUuid();
+    }
+
+    public Map<String, Object> getTemplateVariables() {
+        return mailView.getTemplateVariables();
+    }
+
+    public static ContentView of(ResolvedMailView mailView) {
+        return new ResolvedMailContentView(mailView);
+    }
+
+    private ResolvedMailContentView(ResolvedMailView mailView) {
+        this.mailView = mailView;
+    }
+}

src/main/java/io/mailtrap/model/mailvalidation/ResolvedMailView.java

@@ -0,0 +1,90 @@
+package io.mailtrap.model.mailvalidation;
+
+import io.mailtrap.model.request.emails.Address;
+import io.mailtrap.model.request.emails.BatchEmailBase;
+import io.mailtrap.model.request.emails.EmailAttachment;
+import io.mailtrap.model.request.emails.MailtrapMail;
+import jakarta.validation.Valid;
+import jakarta.validation.constraints.NotEmpty;
+import jakarta.validation.constraints.NotNull;
+import org.apache.commons.lang3.StringUtils;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Read-only overlay that resolves the effective values (either from `base` or mail item) for batch request validation
+ */
+public final class ResolvedMailView {
+
+    // may be null
+    private final BatchEmailBase base;
+    private final MailtrapMail item;
+
+    public ResolvedMailView(BatchEmailBase base, MailtrapMail item) {
+        this.base = base;
+        this.item = item;
+    }
+
+    @NotNull
+    @Valid
+    public Address getFrom() {
+        Address from = item.getFrom();
+
+        if (from == null && base != null) {
+            from = base.getFrom();
+        }
+
+        return from;
+    }
+
+    public String getSubject() {
+        String subject = item.getSubject();
+
+        if (StringUtils.isBlank(subject) && base != null) {
+            subject = base.getSubject();
+        }
+
+        return subject;
+    }
+
+    public String getText() {
+        String text = item.getText();
+
+        if (StringUtils.isBlank(text) && base != null) {
+            text = base.getText();
+        }
+
+        return text;
+    }
+
+    public String getHtml() {
+        String html = item.getHtml();
+
+        if (StringUtils.isBlank(html) && base != null) {
+            html = base.getHtml();
+        }
+
+        return html;
+    }
+
+    public String getTemplateUuid() {
+        String templateUuid = item.getTemplateUuid();
+
+        if (StringUtils.isBlank(templateUuid) && base != null) {
+            templateUuid = base.getTemplateUuid();
+        }
+
+        return templateUuid;
+    }
+
+    public Map<String, Object> getTemplateVariables() {
+        Map<String, Object> templateVariables = item.getTemplateVariables();
+
+        if ((templateVariables == null || templateVariables.isEmpty()) && base != null) {
+            templateVariables = base.getTemplateVariables();
+        }
+
+        return templateVariables;
+    }
+}