Complete DemoController.java with /hello endpoint and add unit tests

Co-authored-by: ffilardi-insight <112668809+ffilardi-insight@users.noreply.github.com>

Author: Copilot

copilot-demo/src/main/java/com/microsoft/hackathon/copilotdemo/controller/DemoController.java

@@ -10,3 +10,14 @@
 * If the key is passed, return "hello <key>".
 * 
 */
+@RestController
+public class DemoController {
+
+    @GetMapping("/hello")
+    public String hello(@RequestParam(required = false) String key) {
+        if (key == null) {
+            return "key not passed";
+        }
+        return "hello " + key;
+    }
+}

copilot-demo/src/test/java/com/microsoft/hackathon/copilotdemo/CopilotDemoApplicationTests.java

@@ -16,5 +16,19 @@ class CopilotDemoApplicationTests {
 	private MockMvc mockMvc;
 
 	// Create a test to check if the /hello GET operation that accepts key as query parameter and returns "hello <key>" is working correctly.
+	@Test
+	void testHelloWithKey() throws Exception {
+		mockMvc.perform(MockMvcRequestBuilders.get("/hello").param("key", "world"))
+				.andExpect(MockMvcResultMatchers.status().isOk())
+				.andExpect(MockMvcResultMatchers.content().string("hello world"));
+	}
+
+	// Create a test to check if the /hello GET operation returns "key not passed" when no key is provided
+	@Test
+	void testHelloWithoutKey() throws Exception {
+		mockMvc.perform(MockMvcRequestBuilders.get("/hello"))
+				.andExpect(MockMvcResultMatchers.status().isOk())
+				.andExpect(MockMvcResultMatchers.content().string("key not passed"));
+	}
 
 }