refactor: the ValidationUtils into validators

Author: QuentinTournier40

src/main/java/dev/resms/ReSMS.java

@@ -45,7 +45,8 @@ public ReSMS(@NonNull ReSMSConfig config) {
    * @throws ReSMSException if fails
    */
   public SendSmsResponse send(@NonNull String to, @NonNull String message) throws ReSMSException {
-    return smsService.send(to, message);
+    SendSmsRequest request = new SendSmsRequest(to, message);
+    return this.send(request);
   }
 
   /**

src/main/java/dev/resms/exception/validation/ReSMSValidationException.java

@@ -0,0 +1,9 @@
+package dev.resms.exception.validation;
+
+import dev.resms.exception.ReSMSException;
+
+public class ReSMSValidationException extends ReSMSException {
+  public ReSMSValidationException(String message) {
+    super(message);
+  }
+}

src/main/java/dev/resms/service/SmsService.java

@@ -5,7 +5,7 @@
 import dev.resms.model.request.SendSmsRequest;
 import dev.resms.model.response.SendSmsResponse;
 import dev.resms.repository.SmsRepository;
-import dev.resms.utils.ValidationUtil;
+import dev.resms.validator.SendSmsValidator;
 import lombok.NonNull;
 
 /** SMS service for sending SMS messages */
@@ -16,21 +16,6 @@ public SmsService(@NonNull ReSMSConfig config) {
     this.apiClient = new SmsRepository(config);
   }
 
-  /**
-   * Sends an SMS message
-   *
-   * @param to Phone number to send the message to
-   * @param message Message content
-   * @return SendSmsResponse containing the message ID and status
-   * @throws ReSMSException if fails
-   */
-  public SendSmsResponse send(@NonNull String to, @NonNull String message) throws ReSMSException {
-    ValidationUtil.validatePhoneNumber(to);
-    ValidationUtil.validateMessage(message);
-    SendSmsRequest request = new SendSmsRequest(to, message);
-    return apiClient.sendSms(request);
-  }
-
   /**
    * Sends an SMS message using request object
    *
@@ -39,7 +24,7 @@ public SendSmsResponse send(@NonNull String to, @NonNull String message) throws
    * @throws ReSMSException if fails
    */
   public SendSmsResponse send(@NonNull SendSmsRequest request) throws ReSMSException {
-    ValidationUtil.validateSendSmsRequest(request);
+    SendSmsValidator.validate(request);
     return apiClient.sendSms(request);
   }
 }

src/main/java/dev/resms/utils/ValidationUtil.java

@@ -0,0 +1,43 @@
+package dev.resms.validator;
+
+import dev.resms.exception.validation.ReSMSValidationException;
+import dev.resms.model.request.SendSmsRequest;
+import lombok.NonNull;
+
+public class SendSmsValidator {
+  private static final String PHONE_NUMBER_REGEX = "^\\+?[1-9]\\d{1,14}$";
+
+  public static void validate(@NonNull SendSmsRequest request) throws ReSMSValidationException {
+    validatePhoneNumber(request.getTo());
+    validateMessage(request.getMessage());
+  }
+
+  /**
+   * Validates a phone number format
+   *
+   * @param phoneNumber Phone number to validate
+   * @throws ReSMSValidationException if the phone number is invalid
+   */
+  public static void validatePhoneNumber(@NonNull String phoneNumber)
+      throws ReSMSValidationException {
+    if (phoneNumber.isBlank()) {
+      throw new ReSMSValidationException("Phone number cannot be empty");
+    }
+
+    if (!phoneNumber.matches(PHONE_NUMBER_REGEX)) {
+      throw new ReSMSValidationException("Invalid phone number format");
+    }
+  }
+
+  /**
+   * Validates message content
+   *
+   * @param message Message to validate
+   * @throws ReSMSValidationException if a message is invalid
+   */
+  public static void validateMessage(@NonNull String message) throws ReSMSValidationException {
+    if (message.isBlank()) {
+      throw new ReSMSValidationException("Message cannot be empty");
+    }
+  }
+}

src/main/java/dev/resms/validator/SendSmsValidator.java

@@ -0,0 +1,43 @@
+package dev.resms.validator;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import dev.resms.exception.validation.ReSMSValidationException;
+import org.junit.jupiter.api.Test;
+
+class SendSmsValidatorTest {
+  @Test
+  void testValidatePhoneNumber_validNumber() {
+    assertDoesNotThrow(() -> SendSmsValidator.validatePhoneNumber("+1234567890"));
+  }
+
+  @Test
+  void testValidatePhoneNumber_emptyNumber() {
+    ReSMSValidationException ex =
+        assertThrows(
+            ReSMSValidationException.class, () -> SendSmsValidator.validatePhoneNumber("  "));
+    assertEquals("Phone number cannot be empty", ex.getMessage());
+  }
+
+  @Test
+  void testValidatePhoneNumber_invalidFormat() {
+    ReSMSValidationException ex =
+        assertThrows(
+            ReSMSValidationException.class, () -> SendSmsValidator.validatePhoneNumber("123abc"));
+    assertEquals("Invalid phone number format", ex.getMessage());
+  }
+
+  @Test
+  void testValidateMessage_validMessage() {
+    assertDoesNotThrow(() -> SendSmsValidator.validateMessage("Hello!"));
+  }
+
+  @Test
+  void testValidateMessage_empty() {
+    ReSMSValidationException ex =
+        assertThrows(ReSMSValidationException.class, () -> SendSmsValidator.validateMessage("   "));
+    assertEquals("Message cannot be empty", ex.getMessage());
+  }
+}