diff --git a/patterns/hexagonal/pom.xml b/patterns/hexagonal/pom.xml
index 7f6cbf176b..4b8dfcfeb4 100644
--- a/patterns/hexagonal/pom.xml
+++ b/patterns/hexagonal/pom.xml
@@ -4,6 +4,22 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>hexagonal</artifactId>
     <version>1.0</version>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>12</source>
+                    <target>12</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.22.2</version>
+            </plugin>
+        </plugins>
+    </build>
     <name>hexagonal</name>
     <description>A quick and practical example of Hexagonal Architecture in Java</description>
 
@@ -14,4 +30,41 @@
         <relativePath>../../parent-java</relativePath>
     </parent>
 
+    <properties>
+        <maven.compiler.target>12</maven.compiler.target>
+        <maven.compiler.source>12</maven.compiler.source>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>5.3.1</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>2.21.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>1.2.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.vintage</groupId>
+            <artifactId>junit-vintage-engine</artifactId>
+            <version>5.2.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <version>2.23.0</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 </project>
diff --git a/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/repository/MockWeatherRepositoryUnitTest.java b/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/repository/MockWeatherRepositoryUnitTest.java
new file mode 100644
index 0000000000..f8d0be5d8b
--- /dev/null
+++ b/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/repository/MockWeatherRepositoryUnitTest.java
@@ -0,0 +1,39 @@
+package com.baeldung.pattern.hexagonal.repository;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class MockWeatherRepositoryUnitTest {
+
+    private final WeatherRepository tested = new MockWeatherRepository();
+
+    @Test
+    void givenLocationClujNapoca_whenGetTemperature_thenExpect17() {
+        double result = tested.getTemperature("cluj-napoca");
+
+        assertEquals(17, result);
+    }
+
+    @Test
+    void givenLocationBucharest_whenGetTemperature_thenExpect22() {
+        double result = tested.getTemperature("bucharest");
+
+        assertEquals(22, result);
+    }
+
+    @Test
+    void givenLocationNewYork_whenGetTemperature_thenExpect15() {
+        double result = tested.getTemperature("new york");
+
+        assertEquals(15, result);
+    }
+
+    @Test
+    void givenLocationDefault_whenGetTemperature_thenExpect20() {
+        double result = tested.getTemperature("default");
+
+        assertEquals(20, result);
+    }
+
+}
\ No newline at end of file
diff --git a/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/repository/RepositoryFactoryUnitTest.java b/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/repository/RepositoryFactoryUnitTest.java
new file mode 100644
index 0000000000..9fc32e5268
--- /dev/null
+++ b/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/repository/RepositoryFactoryUnitTest.java
@@ -0,0 +1,14 @@
+package com.baeldung.pattern.hexagonal.repository;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class RepositoryFactoryUnitTest {
+    @Test
+    void whenGetMockWeatherRepository_thenExpectMockWeatherRepositoryInstance() {
+        WeatherRepository result = RepositoryFactory.getMockWeatherRepository();
+
+        assertTrue(result instanceof MockWeatherRepository);
+    }
+}
\ No newline at end of file
diff --git a/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/service/WeatherForecasterServiceUnitTest.java b/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/service/WeatherForecasterServiceUnitTest.java
new file mode 100644
index 0000000000..1959a815fb
--- /dev/null
+++ b/patterns/hexagonal/src/test/java/com/baeldung/pattern/hexagonal/service/WeatherForecasterServiceUnitTest.java
@@ -0,0 +1,39 @@
+package com.baeldung.pattern.hexagonal.service;
+
+import com.baeldung.pattern.hexagonal.repository.WeatherRepository;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.platform.runner.JUnitPlatform;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+@RunWith(JUnitPlatform.class)
+class WeatherForecasterServiceUnitTest {
+
+    @Mock
+    private WeatherRepository repository;
+    @InjectMocks
+    private WeatherForecasterService tested;
+
+    @Test
+    void givenLocation10_whenForecast_thenExpect10() {
+        when(repository.getTemperature("location")).thenReturn(10d);
+
+        double result = tested.forecast("location");
+        assertEquals(10d, result);
+    }
+
+    @Test
+    void givenNullLocation_whenForecast_thenExpectEmptyString() {
+        when(repository.getTemperature("")).thenReturn(10d);
+
+        double result = tested.forecast(null);
+        assertEquals(10d, result);
+    }
+}
\ No newline at end of file