Unit testing

README.md

@@ -1,3 +1,77 @@
-#  Java URL Shortener
+# Shorten
 
-See full README content in project documentation.
+A lightweight URL shortener built using plain Java with `com.sun.net.httpserver.HttpServer`, H2 Database, and vanilla HTML/CSS/JS frontend.
+
+## ✅ Features
+
+* 🔗 **Anonymous URL shortening**: Convert long URLs into short ones instantly.
+* 🧑‍💻 **User login**: Create an account and log in.
+* 🌐 **Custom short URLs**: Logged-in users can create their own alias URLs.
+* ↪️ **Redirection**: Short URLs automatically redirect to the long ones.
+
+## 🛠️ Tech Stack
+
+| Layer    | Technology                                |
+| -------- | ----------------------------------------- |
+| Frontend | HTML, CSS, JavaScript (no framework)      |
+| Backend  | Java, `com.sun.net.httpserver.HttpServer` |
+| Database | H2 using JDBC                             |
+| Logging  | SLF4J                                     |
+| Testing  | JUnit 5, Mockito                          |
+| CI/CD    | GitHub Actions                            |
+
+```
+
+## 🚀 Getting Started
+
+### Prerequisites
+
+* Java 17+
+* Maven
+
+### Run Application
+
+```bash
+mvn clean package
+java -jar target/shorten.jar
+```
+
+Visit `http://localhost:8080` in your browser.
+
+### Database
+
+* H2 in-memory mode used.
+* JDBC with prepared statements.
+
+### GitHub Actions
+
+* CI configured in `.github/workflows/ci.yml` to run tests on every PR and merge to `main`.
+
+## 🔌 API Endpoints
+
+| Endpoint        | Method | Description                    |
+| --------------- | ------ | ------------------------------ |
+| `/shorten`      | POST   | Shortens a given long URL      |
+| `/s/{shortUrl}` | GET    | Redirects to original long URL |
+| `/register`     | POST   | Register a new user            |
+| `/login`        | POST   | Log in existing user           |
+
+## 🧪 Testing
+
+* All core components are tested with JUnit 5
+* Mocked database and auth dependencies with Mockito
+
+## 📌 Project Management
+
+* [ ] GitHub **Issues** created for each task
+* [ ] Separate **branches** for every feature
+* [ ] Pull Requests with self-review
+* [ ] CI runs on every PR and merge
+
+## 📖 License
+
+This project is licensed under the MIT License.
+
+---
+
+Built with ❤️ using pure Java.

pom.xml

@@ -49,6 +49,12 @@
             <version>5.12.0</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.38</version>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/urlshortener/Server.java

@@ -5,9 +5,11 @@
 import java.net.InetSocketAddress;
 import java.sql.*;
 
+import lombok.extern.slf4j.Slf4j;
 import urlshortener.config.AppConfig;
 import urlshortener.service.*;
 
+@Slf4j
 public class Server {
 
     private static Connection conn;
@@ -29,7 +31,7 @@ public static void main(String[] args) throws Exception {
         server.setExecutor(null);
         server.start();
 
-        System.out.println("Server running on http://localhost:8080/");
+        log.info("Server running on http://localhost:8080/");
     }
 
     public static Connection getConn() {

src/main/java/urlshortener/service/LoginHandler.java

@@ -2,6 +2,7 @@
 
 import com.sun.net.httpserver.HttpExchange;
 import com.sun.net.httpserver.HttpHandler;
+import lombok.extern.slf4j.Slf4j;
 import urlshortener.utils.HelperMethods;
 
 import java.io.File;
@@ -15,6 +16,7 @@
 import java.sql.ResultSet;
 import java.sql.SQLException;
 
+@Slf4j
 public class LoginHandler implements HttpHandler {
 
     private static Connection conn;
@@ -52,16 +54,16 @@ public void handle(HttpExchange exchange) throws IOException {
             ResultSet rs = ps.executeQuery();
 
             if (rs.next()) {
-                System.out.println("Login successful for user: " + username);
+                log.info("Login successful for user: {}", username);
                 String encodedUsername = URLEncoder.encode(username, StandardCharsets.UTF_8.toString());
                 exchange.getResponseHeaders().set("Location", "/index?username=" + encodedUsername);
                 exchange.sendResponseHeaders(302, -1);
             } else {
-                System.out.println("Invalid credentials for user: " + username);
+                log.info("Invalid credentials for user: {}", username);
                 HelperMethods.respond(exchange, 401, "Invalid credentials");
             }
         } catch (SQLException e) {
-            System.err.println("Error querying user: " + e.getMessage());
+            log.error("Error querying user: {}", e.getMessage());
             HelperMethods.respond(exchange, 500, "Database error");
         }
     }

src/main/java/urlshortener/service/RegisterHandler.java

@@ -2,6 +2,7 @@
 
 import com.sun.net.httpserver.HttpExchange;
 import com.sun.net.httpserver.HttpHandler;
+import lombok.extern.slf4j.Slf4j;
 import urlshortener.utils.HelperMethods;
 
 import java.io.File;
@@ -12,6 +13,7 @@
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 
+@Slf4j
 public class RegisterHandler implements HttpHandler {
 
     private static Connection conn;
@@ -48,14 +50,15 @@ public void handle(HttpExchange exchange) throws IOException {
             ps.setString(2, password);
             int rowsAffected = ps.executeUpdate();
             if (rowsAffected > 0) {
-                System.out.println("User registered successfully: " + username);
+                log.info("User registered successfully: {}", username);
                 exchange.getResponseHeaders().set("Location", "/index");
                 exchange.sendResponseHeaders(302, -1);
             } else {
+                log.error("Failed to register user {}", username);
                 HelperMethods.respond(exchange, 500, "Failed to register user");
             }
         } catch (SQLException e) {
-            System.err.println("Error inserting user: " + e.getMessage());
+            log.error("Error inserting user: {}", e.getMessage());
             HelperMethods.respond(exchange, 400, "User already exists");
         }
     }

src/test/java/urlshortener/ServerTest.java

@@ -0,0 +1,55 @@
+package urlshortener;
+
+import org.junit.jupiter.api.*;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.Statement;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+class ServerTest {
+
+    private static Connection conn;
+
+    @BeforeAll
+    static void setupDatabase() throws Exception {
+        // Use real in-memory H2 database for integration-style test
+        conn = DriverManager.getConnection("jdbc:h2:mem:testdb", "sa", "");
+        try (Statement stmt = conn.createStatement()) {
+            stmt.execute("CREATE TABLE users (username VARCHAR(255) PRIMARY KEY, password VARCHAR(255))");
+        }
+    }
+
+    @Test
+    void testUsersTableCreatedSuccessfully() throws Exception {
+        Statement stmt = conn.createStatement();
+        ResultSet rs = stmt.executeQuery("SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'USERS'");
+        assertTrue(rs.next(), "Users table should exist");
+    }
+
+    @Test
+    void testMockedConnectionTableCreation() throws Exception {
+        // Mocks
+        Connection mockConn = mock(Connection.class);
+        Statement mockStmt = mock(Statement.class);
+
+        when(mockConn.createStatement()).thenReturn(mockStmt);
+        when(mockStmt.execute(anyString())).thenReturn(true);
+
+        // Run the DB setup logic
+        mockConn.createStatement().execute("CREATE TABLE users (username VARCHAR(255) PRIMARY KEY, password VARCHAR(255))");
+
+        // Verify SQL execution
+        verify(mockConn).createStatement();
+        verify(mockStmt).execute("CREATE TABLE users (username VARCHAR(255) PRIMARY KEY, password VARCHAR(255))");
+    }
+
+    @Test
+    void testGetConnectionReturnsStaticConnection() throws Exception {
+        Server.main(new String[]{});  // Start the server once
+        assertNotNull(Server.getConn(), "Connection should not be null");
+    }
+}

src/test/java/urlshortener/config/AppConfig.java

@@ -0,0 +1,30 @@
+package urlshortener.config;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.InputStream;
+import java.util.Properties;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class AppConfigTest {
+
+    @Test
+    void testAppConfigPropertiesLoading() {
+        try (InputStream in = AppConfig.class.getClassLoader().getResourceAsStream("application.properties")) {
+            assertNotNull(in, "application.properties file should exist");
+
+            Properties props = new Properties();
+            props.load(in);
+
+            // Verify individual properties
+            assertEquals("8080", props.getProperty("server.port"), "server.port should match");
+            assertEquals("http://localhost:8080", props.getProperty("app.baseUrl"), "app.baseUrl should match");
+            assertEquals("jdbc:h2:./shorten-db", props.getProperty("database.url"), "database.url should match");
+            assertEquals("sa", props.getProperty("database.username"), "database.username should match");
+            assertEquals("", props.getProperty("database.password"), "database.password should match");
+        } catch (Exception e) {
+            fail("Failed to load application.properties: " + e.getMessage());
+        }
+    }
+}

src/test/java/urlshortener/utils/HashGeneratorTest.java

@@ -0,0 +1,22 @@
+package urlshortener.utils;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class HashGeneratorTest {
+
+    @Test
+    void testGenerateShortCode() {
+        // Generate a short code
+        String shortCode = HashGenerator.generateShortCode();
+
+        // Assert that the short code is not null
+        assertNotNull(shortCode, "Short code should not be null");
+
+        // Assert that the short code is not empty
+        assertFalse(shortCode.isEmpty(), "Short code should not be empty");
+
+        // Assert that the short code has the expected length
+        assertEquals(6, shortCode.length(), "Short code should be 6 characters long");
+    }
+}

src/test/java/urlshortener/utils/HelperMethodsTest.java

@@ -0,0 +1,51 @@
+package urlshortener.utils;
+
+import com.sun.net.httpserver.HttpExchange;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+class HelperMethodsTest {
+
+    @Test
+    void testReadRequestBody() throws IOException {
+        // Mock HttpExchange
+        HttpExchange exchange = mock(HttpExchange.class);
+
+        // Mock InputStream with sample request body
+        String requestBody = "testRequestBody";
+        InputStream inputStream = new ByteArrayInputStream(requestBody.getBytes(StandardCharsets.UTF_8));
+        when(exchange.getRequestBody()).thenReturn(inputStream);
+
+        // Call the method
+        String result = HelperMethods.readRequestBody(exchange);
+
+        // Verify the result
+        assertEquals(requestBody, result, "The request body should match the expected value");
+    }
+
+    @Test
+    void testRespond() throws IOException {
+        // Mock HttpExchange
+        HttpExchange exchange = mock(HttpExchange.class);
+
+        // Mock OutputStream
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        when(exchange.getResponseBody()).thenReturn(outputStream);
+
+        // Call the method
+        String response = "testResponse";
+        HelperMethods.respond(exchange, 200, response);
+
+        // Verify the response headers
+        verify(exchange).sendResponseHeaders(200, response.getBytes().length);
+
+        // Verify the response body
+        assertEquals(response, outputStream.toString(), "The response body should match the expected value");
+    }
+}

src/test/resources/application.properties

@@ -0,0 +1,8 @@
+# Server configuration
+server.port=8080
+app.baseUrl=http://localhost:8080
+
+# Database configuration
+database.url=jdbc:h2:./shorten-db
+database.username=sa
+database.password=