Refactor OTPService with testing and Full JavaDocs (#23)

- Complete JavaDocs for all methods
- Remove unused port field from `RedisConfig`.
- Remove unneeded `junit-jupiter` maven dependency since it's included with `spring-boot-starter-test`.
- Add `testcontainers-redis` maven dependency to include `RedisContainer` instead of `GenericContainer`.
- Rename `send` method in `OTPService` to `sendOTP`.
- Convert OTP message to be constant.
- Add public modifier for exception handler.
- Rename tests names and display messages for Should_When convention.
- Rename constant strings with MESSAGE suffix.

Author: Ahmad-AlDeeb

config/.pre-commit-config.yaml

@@ -4,7 +4,7 @@ repos:
     hooks:
       - id: trailing-whitespace
       - id: end-of-file-fixer
-      - id: check-yaml # Validates the syntax of YAML files.
+      - id: check-yaml
 
   - repo: local
     hooks:

pom.xml

@@ -64,12 +64,6 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter</artifactId>
-            <version>5.8.1</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>org.testcontainers</groupId>
             <artifactId>junit-jupiter</artifactId>
@@ -82,6 +76,12 @@
             <version>1.20.0</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.redis</groupId>
+            <artifactId>testcontainers-redis</artifactId>
+            <version>2.2.2</version>
+            <scope>test</scope>
+        </dependency>
         <!--==================== Redis ====================-->
         <dependency>
             <groupId>org.springframework.boot</groupId>

src/main/java/com/ittovative/otpservice/OtpServiceApplication.java

@@ -21,9 +21,14 @@
 public class OtpServiceApplication {
 
     /**
-     * The entry point of application.
+     * The entry point of the OTP Service application.
+     * <p>
+     * This method starts the Spring Boot application by invoking {@link SpringApplication#run(Class, String...)}.
+     * It serves as the main entry point to launch the OTP service,
+     * which handles OTP generation, validation, and related tasks.
+     * </p>
      *
-     * @param args the input arguments
+     * @param args The input arguments passed from the command line.
      */
     public static void main(final String[] args) {
         SpringApplication.run(OtpServiceApplication.class, args);

src/main/java/com/ittovative/otpservice/config/RedisConfig.java

@@ -1,25 +1,21 @@
 package com.ittovative.otpservice.config;
 
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
 import org.springframework.data.redis.core.RedisTemplate;
 
 @Configuration
 public class RedisConfig {
-    @Value("${spring.data.redis.port}")
-    private static int port;
-
-    public static int getPort() {
-        return port;
-    }
 
     /**
-     * Redis template.
+     * Creates and configures a {@link RedisTemplate} for interacting with Redis.
+     * <p>
+     * This template provides a high-level abstraction for Redis operations using
+     * the given {@link RedisConnectionFactory} to establish the connection.
      *
-     * @param connectionFactory the connection factory
-     * @return the redis template
+     * @param connectionFactory the Redis connection factory used to establish the connection
+     * @return a configured {@link RedisTemplate} for Redis operations
      */
     @Bean
     public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {

src/main/java/com/ittovative/otpservice/config/TwilioConfig.java

@@ -13,15 +13,19 @@ public class TwilioConfig {
     @Value("${twilio.auth-token}")
     private String authToken;
 
-    @Value("${twilio.verified-number}")
-    private static String verifiedNumber;
-
-    public static String getVerifiedNumber() {
-        return verifiedNumber;
-    }
-
     /**
-     * Initialize Twilio with account SID and auth token.
+     * Initializes the Twilio API with the provided account SID and authentication token.
+     * <p>
+     * This method is annotated with {@code @PostConstruct}, ensuring that it is called
+     * automatically after the Spring container has set up all the properties and dependencies
+     * for the {@code TwilioConfig} bean. It uses the {@link com.twilio.Twilio#init(String, String)}
+     * method to initialize the Twilio SDK.
+     * </p>
+     *
+     * <p>
+     * This configuration allows the application to interact with the Twilio API for sending SMS,
+     * making calls, or using other Twilio services.
+     * </p>
      */
     @PostConstruct
     public void initialize() {

src/main/java/com/ittovative/otpservice/constant/APIResponseConstant.java

@@ -1,12 +1,12 @@
 package com.ittovative.otpservice.constant;
 
-import static com.ittovative.otpservice.constant.ExceptionConstant.UTILITY_CLASS_INSTANTIATION;
+import static com.ittovative.otpservice.constant.ExceptionConstant.UTILITY_CLASS_INSTANTIATION_MESSAGE;
 
 public final class APIResponseConstant {
-    public static final String OTP_SENT = "OTP sent successfully!";
-    public static final String TOKEN_VERIFIED = "Token verified successfully!";
+    public static final String OTP_SENT_MESSAGE = "OTP sent successfully!";
+    public static final String TOKEN_VERIFIED_MESSAGE = "Token verified successfully!";
 
     private APIResponseConstant() {
-        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION);
+        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION_MESSAGE);
     }
 }

src/main/java/com/ittovative/otpservice/constant/AspectConstant.java

@@ -1,13 +1,13 @@
 package com.ittovative.otpservice.constant;
 
-import static com.ittovative.otpservice.constant.ExceptionConstant.UTILITY_CLASS_INSTANTIATION;
+import static com.ittovative.otpservice.constant.ExceptionConstant.UTILITY_CLASS_INSTANTIATION_MESSAGE;
 
 public final class AspectConstant {
     public static final String BEFORE_MESSAGE = "Executing ===> {}.{} with arguments: [{}]";
     public static final String AFTER_RETURN_MESSAGE = "Finished ===> {}.{} with arguments: [{}] and returned {}";
     public static final String AFTER_THROW_MESSAGE = "Exception {} in ===> {}.{} with arguments: [{}]";
 
     private AspectConstant() {
-        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION);
+        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION_MESSAGE);
     }
 }

src/main/java/com/ittovative/otpservice/constant/ExceptionConstant.java

@@ -1,16 +1,16 @@
 package com.ittovative.otpservice.constant;
 
 public final class ExceptionConstant {
-    public static final String UTILITY_CLASS_INSTANTIATION = "Utility class should not be instantiated!";
-    public static final String VALIDATION_ERROR = "Validation error!";
-    public static final String INVALID_PHONE_NUMBER_FORMAT =
+    public static final String UTILITY_CLASS_INSTANTIATION_MESSAGE = "Utility class should not be instantiated!";
+    public static final String VALIDATION_ERROR_MESSAGE = "Validation error!";
+    public static final String INVALID_PHONE_NUMBER_FORMAT_MESSAGE =
             "Invalid phone number format! (only digits, plus-sign and dashes are allowed).";
-    public static final String INVALID_TOKEN_FORMAT = "Token must be a 6-digit number!";
-    public static final String INVALID_TOKEN = "Invalid token!";
-    public static final String TOKEN_EXPIRED = "Token has expired!";
+    public static final String INVALID_TOKEN_FORMAT_MESSAGE = "Token must be a 6-digit number!";
+    public static final String INVALID_TOKEN_MESSAGE = "Invalid token!";
+    public static final String TOKEN_EXPIRED_MESSAGE = "Token has expired!";
 
 
     private ExceptionConstant() {
-        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION);
+        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION_MESSAGE);
     }
 }

src/main/java/com/ittovative/otpservice/constant/HTTPConstant.java

@@ -1,6 +1,6 @@
 package com.ittovative.otpservice.constant;
 
-import static com.ittovative.otpservice.constant.ExceptionConstant.UTILITY_CLASS_INSTANTIATION;
+import static com.ittovative.otpservice.constant.ExceptionConstant.UTILITY_CLASS_INSTANTIATION_MESSAGE;
 
 public final class HTTPConstant {
     public static final String APPLICATION_JSON = "application/json";
@@ -19,6 +19,6 @@ public final class HTTPConstant {
     public static final String TOO_MANY_REQUESTS = "429";
 
     private HTTPConstant() {
-        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION);
+        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION_MESSAGE);
     }
 }

src/main/java/com/ittovative/otpservice/constant/RedisConstant.java

@@ -2,7 +2,7 @@
 
 import org.springframework.beans.factory.annotation.Value;
 
-import static com.ittovative.otpservice.constant.ExceptionConstant.UTILITY_CLASS_INSTANTIATION;
+import static com.ittovative.otpservice.constant.ExceptionConstant.UTILITY_CLASS_INSTANTIATION_MESSAGE;
 
 public final class RedisConstant {
     public static final String VERIFICATION_TOKEN_HASH = "VerificationToken";
@@ -11,6 +11,6 @@ public final class RedisConstant {
     public static final Integer EXPIRY_DATE_IN_MIN = 5;
 
     private RedisConstant() {
-        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION);
+        throw new IllegalStateException(UTILITY_CLASS_INSTANTIATION_MESSAGE);
     }
 }