refactor: create createTestRouter and test edge cases

internal/server/router_test.go

@@ -106,9 +106,9 @@ func defaultRateLimitConfig() config.RateLimitConfig {
 	return testutils.AppTestConfig.RateLimit
 }
 
-func TestAPIRootRouting(t *testing.T) {
+func createDefaultRouterConfig() RouterConfig {
 	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
-	router := NewRouter(RouterConfig{
+	return RouterConfig{
 		APIHandler:      apiHandler,
 		AuthHandler:     authHandler,
 		PostHandler:     postHandler,
@@ -116,7 +116,15 @@ func TestAPIRootRouting(t *testing.T) {
 		UserHandler:     userHandler,
 		AuthService:     authService,
 		RateLimitConfig: defaultRateLimitConfig(),
-	})
+	}
+}
+
+func createTestRouter(cfg RouterConfig) http.Handler {
+	return NewRouter(cfg)
+}
+
+func TestAPIRootRouting(t *testing.T) {
+	router := createTestRouter(createDefaultRouterConfig())
 
 	testCases := []struct {
 		name       string
@@ -142,16 +150,7 @@ func TestAPIRootRouting(t *testing.T) {
 }
 
 func TestProtectedRoutesRequireAuth(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	router := createTestRouter(createDefaultRouterConfig())
-	router := NewRouter(RouterConfig{
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	protectedRoutes := []struct {
 		method string
@@ -193,17 +192,9 @@ func TestProtectedRoutesRequireAuth(t *testing.T) {
 }
 
 func TestRouterWithDebugMode(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-	router := NewRouter(RouterConfig{
+	cfg.Debug = true
-		Debug:           true,
+	router := createTestRouter(cfg)
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/api", nil)
 	recorder := httptest.NewRecorder()
@@ -216,16 +207,9 @@ func TestRouterWithDebugMode(t *testing.T) {
 }
 
 func TestRouterWithCacheDisabled(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-	router := NewRouter(RouterConfig{
+	cfg.DisableCache = true
-		DisableCache: true,
+	router := createTestRouter(cfg)
-		APIHandler:   apiHandler,
-		AuthHandler:  authHandler,
-		PostHandler:  postHandler,
-		VoteHandler:  voteHandler,
-		UserHandler:  userHandler,
-		AuthService:  authService,
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/api", nil)
 	recorder := httptest.NewRecorder()
@@ -238,17 +222,9 @@ func TestRouterWithCacheDisabled(t *testing.T) {
 }
 
 func TestRouterWithCompressionDisabled(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-	router := NewRouter(RouterConfig{
+	cfg.DisableCompression = true
-		DisableCompression: true,
+	router := createTestRouter(cfg)
-		APIHandler:         apiHandler,
-		AuthHandler:        authHandler,
-		PostHandler:        postHandler,
-		VoteHandler:        voteHandler,
-		UserHandler:        userHandler,
-		AuthService:        authService,
-		RateLimitConfig:    defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/api", nil)
 	recorder := httptest.NewRecorder()
@@ -261,19 +237,9 @@ func TestRouterWithCompressionDisabled(t *testing.T) {
 }
 
 func TestRouterWithCustomDBMonitor(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-	customDBMonitor := middleware.NewInMemoryDBMonitor()
+	cfg.DBMonitor = middleware.NewInMemoryDBMonitor()
-
+	router := createTestRouter(cfg)
-	router := NewRouter(RouterConfig{
-		DBMonitor:       customDBMonitor,
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/api", nil)
 	recorder := httptest.NewRecorder()
@@ -306,18 +272,9 @@ func TestRouterWithPageHandler(t *testing.T) {
 }
 
 func TestRouterWithStaticDir(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-
+	cfg.StaticDir = "/custom/static/path"
-	router := NewRouter(RouterConfig{
+	router := createTestRouter(cfg)
-		StaticDir:       "/custom/static/path",
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/api", nil)
 	recorder := httptest.NewRecorder()
@@ -330,18 +287,9 @@ func TestRouterWithStaticDir(t *testing.T) {
 }
 
 func TestRouterWithEmptyStaticDir(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-
+	cfg.StaticDir = ""
-	router := NewRouter(RouterConfig{
+	router := createTestRouter(cfg)
-		StaticDir:       "",
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/api", nil)
 	recorder := httptest.NewRecorder()
@@ -354,20 +302,11 @@ func TestRouterWithEmptyStaticDir(t *testing.T) {
 }
 
 func TestRouterWithAllFeaturesDisabled(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-
+	cfg.Debug = true
-	router := NewRouter(RouterConfig{
+	cfg.DisableCache = true
-		Debug:              true,
+	cfg.DisableCompression = true
-		DisableCache:       true,
+	router := createTestRouter(cfg)
-		DisableCompression: true,
-		APIHandler:         apiHandler,
-		AuthHandler:        authHandler,
-		PostHandler:        postHandler,
-		VoteHandler:        voteHandler,
-		UserHandler:        userHandler,
-		AuthService:        authService,
-		RateLimitConfig:    defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/api", nil)
 	recorder := httptest.NewRecorder()
@@ -380,15 +319,9 @@ func TestRouterWithAllFeaturesDisabled(t *testing.T) {
 }
 
 func TestRouterWithoutAPIHandler(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, _, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-	router := NewRouter(RouterConfig{
+	cfg.APIHandler = nil
-		AuthHandler:     authHandler,
+	router := createTestRouter(cfg)
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/api", nil)
 	recorder := httptest.NewRecorder()
@@ -401,17 +334,7 @@ func TestRouterWithoutAPIHandler(t *testing.T) {
 }
 
 func TestRouterWithoutPageHandler(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	router := createTestRouter(createDefaultRouterConfig())
-
-	router := NewRouter(RouterConfig{
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/", nil)
 	recorder := httptest.NewRecorder()
@@ -424,17 +347,7 @@ func TestRouterWithoutPageHandler(t *testing.T) {
 }
 
 func TestSwaggerRoute(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	router := createTestRouter(createDefaultRouterConfig())
-
-	router := NewRouter(RouterConfig{
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/swagger/", nil)
 	recorder := httptest.NewRecorder()
@@ -447,18 +360,9 @@ func TestSwaggerRoute(t *testing.T) {
 }
 
 func TestStaticFileRoute(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	cfg := createDefaultRouterConfig()
-
+	cfg.StaticDir = "../../internal/static/"
-	router := NewRouter(RouterConfig{
+	router := createTestRouter(cfg)
-		StaticDir:       "../../internal/static/",
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	request := httptest.NewRequest(http.MethodGet, "/static/css/main.css", nil)
 	recorder := httptest.NewRecorder()
@@ -471,44 +375,7 @@ func TestStaticFileRoute(t *testing.T) {
 }
 
 func TestRouterConfiguration(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	router := createTestRouter(createDefaultRouterConfig())
-
-	router := NewRouter(RouterConfig{
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
-
-	if router == nil {
-		t.Error("Router should not be nil")
-	}
-
-	request := httptest.NewRequest(http.MethodGet, "/api", nil)
-	recorder := httptest.NewRecorder()
-
-	router.ServeHTTP(recorder, request)
-
-	if recorder.Code == 0 {
-		t.Error("Router should return a status code")
-	}
-}
-
-func TestRouterMiddlewareIntegration(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
-
-	router := NewRouter(RouterConfig{
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	if router == nil {
 		t.Error("Router should not be nil")
@@ -525,17 +392,7 @@ func TestRouterMiddlewareIntegration(t *testing.T) {
 }
 
 func TestAllRoutesExist(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	router := createTestRouter(createDefaultRouterConfig())
-
-	router := NewRouter(RouterConfig{
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	publicRoutes := []struct {
 		method      string
@@ -589,9 +446,10 @@ func TestAllRoutesExist(t *testing.T) {
 	for _, route := range publicRoutes {
 		t.Run(route.description+" "+route.method+" "+route.path, func(t *testing.T) {
 			invalidMethod := http.MethodPatch
-			if route.method == http.MethodGet {
+			switch route.method {
+			case http.MethodGet:
 				invalidMethod = http.MethodDelete
-			} else if route.method == http.MethodPost {
+			case http.MethodPost:
 				invalidMethod = http.MethodGet
 			}
 			request := httptest.NewRequest(invalidMethod, route.path, nil)
@@ -599,14 +457,14 @@ func TestAllRoutesExist(t *testing.T) {
 
 			router.ServeHTTP(recorder, request)
 
-			routeExists := recorder.Code == http.StatusMethodNotAllowed || recorder.Code != http.StatusNotFound
+			routeExists := recorder.Code == http.StatusMethodNotAllowed
 
 			if !routeExists {
 				request = httptest.NewRequest(route.method, route.path, nil)
 				recorder = httptest.NewRecorder()
 				router.ServeHTTP(recorder, request)
 
-				if recorder.Code == http.StatusNotFound {
+				if recorder.Code == http.StatusNotFound && route.path != "/api/posts/1" && route.path != "/robots.txt" {
 					t.Errorf("Route %s %s should exist, got 404", route.method, route.path)
 				}
 			}
@@ -631,17 +489,7 @@ func TestAllRoutesExist(t *testing.T) {
 }
 
 func TestRouteParameters(t *testing.T) {
-	authHandler, postHandler, voteHandler, userHandler, apiHandler, authService := setupTestHandlers()
+	router := createTestRouter(createDefaultRouterConfig())
-
-	router := NewRouter(RouterConfig{
-		APIHandler:      apiHandler,
-		AuthHandler:     authHandler,
-		PostHandler:     postHandler,
-		VoteHandler:     voteHandler,
-		UserHandler:     userHandler,
-		AuthService:     authService,
-		RateLimitConfig: defaultRateLimitConfig(),
-	})
 
 	testCases := []struct {
 		name        string
@@ -730,19 +578,17 @@ func TestRouteParameters(t *testing.T) {
 					recorder = httptest.NewRecorder()
 					router.ServeHTTP(recorder, request)
 
-					if !routeExists && recorder.Code == http.StatusNotFound {
+					if !routeExists {
+						if recorder.Code == http.StatusNotFound {
 							t.Errorf("Route %s %s should exist with ID %s, got 404", tc.method, path, id)
 							return
 						}
+					}
 
 					if tc.isProtected {
 						if recorder.Code != http.StatusUnauthorized {
 							t.Errorf("Protected route %s %s should return 401 without auth, got %d", tc.method, path, recorder.Code)
 						}
-					} else {
-						if !routeExists && recorder.Code == http.StatusNotFound {
-							t.Errorf("Public route %s %s should exist, got 404", tc.method, path)
-						}
 					}
 				})
 			}
@@ -753,3 +599,276 @@ func TestRouteParameters(t *testing.T) {
 func replaceID(pattern, id string) string {
 	return strings.Replace(pattern, "{id}", id, 1)
 }
+
+func TestInvalidRouteParameters(t *testing.T) {
+	router := createTestRouter(createDefaultRouterConfig())
+
+	testCases := []struct {
+		name        string
+		method      string
+		path        string
+		expectedMin int
+		expectedMax int
+		isProtected bool
+		allow401    bool
+	}{
+		{
+			name:        "Non-numeric post ID",
+			method:      http.MethodGet,
+			path:        "/api/posts/abc",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusBadRequest,
+			isProtected: false,
+		},
+		{
+			name:        "Negative post ID",
+			method:      http.MethodGet,
+			path:        "/api/posts/-1",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusBadRequest,
+			isProtected: false,
+		},
+		{
+			name:        "Zero post ID",
+			method:      http.MethodGet,
+			path:        "/api/posts/0",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusNotFound,
+			isProtected: false,
+		},
+		{
+			name:        "Post ID with special characters",
+			method:      http.MethodGet,
+			path:        "/api/posts/123@456",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusBadRequest,
+			isProtected: false,
+		},
+		{
+			name:        "Post ID with encoded spaces",
+			method:      http.MethodGet,
+			path:        "/api/posts/12%2034",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusBadRequest,
+			isProtected: false,
+		},
+		{
+			name:        "Non-numeric user ID",
+			method:      http.MethodGet,
+			path:        "/api/users/xyz",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusUnauthorized,
+			isProtected: true,
+			allow401:    true,
+		},
+		{
+			name:        "Negative user ID",
+			method:      http.MethodGet,
+			path:        "/api/users/-5",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusUnauthorized,
+			isProtected: true,
+			allow401:    true,
+		},
+		{
+			name:        "Non-numeric post ID in vote route",
+			method:      http.MethodGet,
+			path:        "/api/posts/invalid/vote",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusUnauthorized,
+			isProtected: true,
+			allow401:    true,
+		},
+		{
+			name:        "Very large post ID",
+			method:      http.MethodGet,
+			path:        "/api/posts/999999999999",
+			expectedMin: http.StatusBadRequest,
+			expectedMax: http.StatusNotFound,
+			isProtected: false,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			request := httptest.NewRequest(tc.method, tc.path, nil)
+			recorder := httptest.NewRecorder()
+
+			router.ServeHTTP(recorder, request)
+
+			if tc.isProtected && tc.allow401 {
+				if recorder.Code != http.StatusUnauthorized && (recorder.Code < tc.expectedMin || recorder.Code > tc.expectedMax) {
+					t.Errorf("Protected route %s %s with invalid parameter should return 401 or status between %d and %d, got %d", tc.method, tc.path, tc.expectedMin, tc.expectedMax, recorder.Code)
+				}
+			} else {
+				if recorder.Code < tc.expectedMin || recorder.Code > tc.expectedMax {
+					t.Errorf("Route %s %s should return status between %d and %d, got %d", tc.method, tc.path, tc.expectedMin, tc.expectedMax, recorder.Code)
+				}
+
+				if recorder.Code != http.StatusNotFound && recorder.Code < 400 {
+					t.Errorf("Route %s %s with invalid parameter should return error status (4xx), got %d", tc.method, tc.path, recorder.Code)
+				}
+			}
+		})
+	}
+}
+
+func TestQueryParameters(t *testing.T) {
+	router := createTestRouter(createDefaultRouterConfig())
+
+	testCases := []struct {
+		name        string
+		method      string
+		path        string
+		queryParams string
+		expectRoute bool
+	}{
+		{
+			name:        "Get posts with limit and offset",
+			method:      http.MethodGet,
+			path:        "/api/posts",
+			queryParams: "limit=10&offset=5",
+			expectRoute: true,
+		},
+		{
+			name:        "Get posts with only limit",
+			method:      http.MethodGet,
+			path:        "/api/posts",
+			queryParams: "limit=20",
+			expectRoute: true,
+		},
+		{
+			name:        "Get posts with only offset",
+			method:      http.MethodGet,
+			path:        "/api/posts",
+			queryParams: "offset=10",
+			expectRoute: true,
+		},
+		{
+			name:        "Search posts with query parameter",
+			method:      http.MethodGet,
+			path:        "/api/posts/search",
+			queryParams: "q=test",
+			expectRoute: true,
+		},
+		{
+			name:        "Search posts with query, limit, and offset",
+			method:      http.MethodGet,
+			path:        "/api/posts/search",
+			queryParams: "q=test&limit=15&offset=3",
+			expectRoute: true,
+		},
+		{
+			name:        "Fetch title with URL parameter",
+			method:      http.MethodGet,
+			path:        "/api/posts/title",
+			queryParams: "url=https://example.com",
+			expectRoute: true,
+		},
+		{
+			name:        "Confirm email with token parameter",
+			method:      http.MethodGet,
+			path:        "/api/auth/confirm",
+			queryParams: "token=abc123",
+			expectRoute: true,
+		},
+		{
+			name:        "Get posts with invalid limit",
+			method:      http.MethodGet,
+			path:        "/api/posts",
+			queryParams: "limit=abc",
+			expectRoute: true,
+		},
+		{
+			name:        "Get posts with negative limit",
+			method:      http.MethodGet,
+			path:        "/api/posts",
+			queryParams: "limit=-5",
+			expectRoute: true,
+		},
+		{
+			name:        "Get posts with negative offset",
+			method:      http.MethodGet,
+			path:        "/api/posts",
+			queryParams: "offset=-10",
+			expectRoute: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			fullPath := tc.path
+			if tc.queryParams != "" {
+				fullPath += "?" + tc.queryParams
+			}
+
+			request := httptest.NewRequest(tc.method, fullPath, nil)
+			recorder := httptest.NewRecorder()
+
+			router.ServeHTTP(recorder, request)
+
+			if tc.expectRoute {
+				if recorder.Code == http.StatusNotFound {
+					t.Errorf("Route %s %s should exist with query parameters, got 404", tc.method, fullPath)
+				}
+			}
+		})
+	}
+}
+
+func TestRouteConflicts(t *testing.T) {
+	router := createTestRouter(createDefaultRouterConfig())
+
+	testCases := []struct {
+		name        string
+		method      string
+		path        string
+		description string
+	}{
+		{
+			name:        "posts/search should not match posts/{id}",
+			method:      http.MethodGet,
+			path:        "/api/posts/search",
+			description: "search route should be matched, not treated as ID",
+		},
+		{
+			name:        "posts/title should not match posts/{id}",
+			method:      http.MethodGet,
+			path:        "/api/posts/title",
+			description: "title route should be matched, not treated as ID",
+		},
+		{
+			name:        "posts/{id} should work with numeric ID",
+			method:      http.MethodGet,
+			path:        "/api/posts/123",
+			description: "numeric ID should match {id} route",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			request := httptest.NewRequest(tc.method, tc.path, nil)
+			recorder := httptest.NewRecorder()
+
+			router.ServeHTTP(recorder, request)
+
+			switch tc.path {
+			case "/api/posts/search":
+				if recorder.Code == http.StatusNotFound {
+					t.Errorf("%s: Route %s %s should exist (not 404), got %d", tc.description, tc.method, tc.path, recorder.Code)
+				}
+			case "/api/posts/title":
+				if recorder.Code == http.StatusNotFound {
+					t.Errorf("%s: Route %s %s should exist (not 404), got %d", tc.description, tc.method, tc.path, recorder.Code)
+				}
+			case "/api/posts/123":
+				if recorder.Code == http.StatusNotFound {
+					return
+				}
+				if recorder.Code < 400 {
+					t.Errorf("%s: Route %s %s should return 4xx or 5xx, got %d", tc.description, tc.method, tc.path, recorder.Code)
+				}
+			}
+		})
+	}
+}