feat: add ExpenseListController validation and authorization tests

src/main/java/de/zendric/app/xpensely_server/controller/ExpenseListController.java

@@ -19,7 +19,7 @@ import de.zendric.app.xpensely_server.services.UserService;
 
 @RestController
 @RequestMapping("/api/expenselist")
-class ExpenseListController {
+public class ExpenseListController {
 
     private final ExpenseListService expenseListService;
     private final UserService userService;

src/test/java/de/zendric/app/xpensely_Server/controller/ExpenseListControllerTest.java

@@ -0,0 +1,135 @@
+package de.zendric.app.xpensely_Server.controller;
+
+import de.zendric.app.xpensely_server.controller.ExpenseListController;
+import de.zendric.app.xpensely_server.model.AppUser;
+import de.zendric.app.xpensely_server.model.ExpenseList;
+import de.zendric.app.xpensely_server.security.AuthenticatedUserResolver;
+import de.zendric.app.xpensely_server.services.CategoryService;
+import de.zendric.app.xpensely_server.services.ExpenseListService;
+import de.zendric.app.xpensely_server.services.UserService;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.util.List;
+import java.util.Optional;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
+
+@WebMvcTest(ExpenseListController.class)
+@AutoConfigureMockMvc(addFilters = false)
+@ActiveProfiles("test")
+class ExpenseListControllerTest {
+
+    @Autowired MockMvc mockMvc;
+    @MockitoBean ExpenseListService expenseListService;
+    @MockitoBean UserService userService;
+    @MockitoBean CategoryService categoryService;
+    @MockitoBean AuthenticatedUserResolver authenticatedUserResolver;
+
+    // --- Validation tests ---
+
+    @Test
+    void addExpense_blankTitle_returns400() throws Exception {
+        mockMvc.perform(post("/api/expenselist/1/add")
+                .contentType(MediaType.APPLICATION_JSON)
+                .content("{\"title\":\"\",\"owner\":\"alice\",\"amount\":10.0,\"date\":\"2026-05-04\",\"category\":\"Food\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.title").exists());
+    }
+
+    @Test
+    void addExpense_negativeAmount_returns400() throws Exception {
+        mockMvc.perform(post("/api/expenselist/1/add")
+                .contentType(MediaType.APPLICATION_JSON)
+                .content("{\"title\":\"Lunch\",\"owner\":\"alice\",\"amount\":-5.0,\"date\":\"2026-05-04\",\"category\":\"Food\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.amount").exists());
+    }
+
+    @Test
+    void addExpense_nullDate_returns400() throws Exception {
+        mockMvc.perform(post("/api/expenselist/1/add")
+                .contentType(MediaType.APPLICATION_JSON)
+                .content("{\"title\":\"Lunch\",\"owner\":\"alice\",\"amount\":10.0,\"category\":\"Food\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.date").exists());
+    }
+
+    @Test
+    void acceptInvite_blankCode_returns400() throws Exception {
+        mockMvc.perform(post("/api/expenselist/accept-invite")
+                .contentType(MediaType.APPLICATION_JSON)
+                .content("{\"inviteCode\":\"\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.inviteCode").exists());
+    }
+
+    @Test
+    void acceptInvite_wrongCodeLength_returns400() throws Exception {
+        mockMvc.perform(post("/api/expenselist/accept-invite")
+                .contentType(MediaType.APPLICATION_JSON)
+                .content("{\"inviteCode\":\"ABC\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.inviteCode").exists());
+    }
+
+    // --- Authorization tests ---
+
+    @Test
+    void getById_authenticatedUserNotMember_returns403() throws Exception {
+        AppUser owner = new AppUser(); owner.setId(1L);
+        AppUser requester = new AppUser(); requester.setId(2L);
+        ExpenseList list = new ExpenseList(); list.setId(1L); list.setOwner(owner);
+
+        when(expenseListService.findById(1L)).thenReturn(Optional.of(list));
+        when(authenticatedUserResolver.resolveCurrentUser(any())).thenReturn(requester);
+
+        mockMvc.perform(get("/api/expenselist/byId").param("id", "1"))
+                .andExpect(status().isForbidden());
+    }
+
+    @Test
+    void getById_authenticatedUserIsOwner_returns200() throws Exception {
+        AppUser owner = new AppUser(); owner.setId(1L);
+        ExpenseList list = new ExpenseList(); list.setId(1L); list.setOwner(owner);
+
+        when(expenseListService.findById(1L)).thenReturn(Optional.of(list));
+        when(authenticatedUserResolver.resolveCurrentUser(any())).thenReturn(owner);
+
+        mockMvc.perform(get("/api/expenselist/byId").param("id", "1"))
+                .andExpect(status().isOk());
+    }
+
+    @Test
+    void deleteList_nonOwner_returns403() throws Exception {
+        AppUser owner = new AppUser(); owner.setId(1L);
+        AppUser nonOwner = new AppUser(); nonOwner.setId(2L);
+        ExpenseList list = new ExpenseList(); list.setId(5L); list.setOwner(owner);
+
+        when(expenseListService.findById(5L)).thenReturn(Optional.of(list));
+        when(authenticatedUserResolver.resolveCurrentUser(any())).thenReturn(nonOwner);
+
+        mockMvc.perform(delete("/api/expenselist/5"))
+                .andExpect(status().isForbidden());
+    }
+
+    @Test
+    void getMine_returnsCurrentUserLists() throws Exception {
+        AppUser user = new AppUser(); user.setId(3L);
+
+        when(authenticatedUserResolver.resolveCurrentUser(any())).thenReturn(user);
+        when(expenseListService.findByUserId(3L)).thenReturn(List.of(new ExpenseList()));
+
+        mockMvc.perform(get("/api/expenselist/mine"))
+                .andExpect(status().isOk());
+    }
+}