src/test/java/com/example/demo/controller/HelloControllerTest.java

@@ -0,0 +1,48 @@
+package com.example.demo.controller;
+
+import com.example.demo.service.HelloService;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@WebMvcTest(HelloController.class)
+@DisplayName("HelloController Unit Tests")
+class HelloControllerTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @MockBean
+    private HelloService helloService;
+
+    @Test
+    @DisplayName("GET /api/hello returns default greeting")
+    void greet_ReturnsDefaultGreeting() throws Exception {
+        when(helloService.getGreeting()).thenReturn("Hello, World!");
+
+        mockMvc.perform(get("/api/hello")
+                        .accept(MediaType.APPLICATION_JSON))
+                .andExpect(status().isOk())
+                .andExpect(content().string("Hello, World!"));
+    }
+
+    @Test
+    @DisplayName("GET /api/hello/{name} returns personalized greeting")
+    void greetWithName_ReturnsPersonalizedGreeting() throws Exception {
+        when(helloService.getGreetingFor("Developer")).thenReturn("Hello, Developer!");
+
+        mockMvc.perform(get("/api/hello/Developer")
+                        .accept(MediaType.APPLICATION_JSON))
+                .andExpect(status().isOk())
+                .andExpect(content().string("Hello, Developer!"));
+    }
+}