Add basic 404 handling

web/main.go

@@ -98,8 +98,12 @@ func main() {
 
 		board, err := database.GetBoard(db, slug)
 		if err != nil {
-			http.NotFound(w, r)
-			log.Printf("Board %q not found: %v", slug, err)
+			if errors.Is(err, sql.ErrNoRows) {
+				views.NotFound().Render(r.Context(), w)
+				return
+			}
+			http.Error(w, "Failed to get board", http.StatusInternalServerError)
+			log.Printf("Failed to get board%q: %v", slug, err)
 			return
 		}
 
@@ -118,13 +122,21 @@ func main() {
 
 		board, err := database.GetBoard(db, slug)
 		if err != nil {
-			http.NotFound(w, r)
-			log.Printf("Board %q not found: %v", slug, err)
+			if errors.Is(err, sql.ErrNoRows) {
+				views.NotFound().Render(r.Context(), w)
+				return
+			}
+			http.Error(w, "Failed to get board", http.StatusInternalServerError)
+			log.Printf("Failed to get board%q: %v", slug, err)
 			return
 		}
 
 		thread, err := database.GetThread(db, threadId)
 		if err != nil {
+			if errors.Is(err, sql.ErrNoRows) {
+				views.NotFound().Render(r.Context(), w)
+				return
+			}
 			http.Error(w, "Failed to get thread", http.StatusInternalServerError)
 			log.Printf("Failed to get thread %q: %v", threadIdStr, err)
 			return
@@ -464,6 +476,10 @@ func main() {
 
 		thread, err := database.GetThread(db, threadId)
 		if err != nil {
+			if errors.Is(err, sql.ErrNoRows) {
+				views.NotFound().Render(r.Context(), w)
+				return
+			}
 			http.Error(w, "Failed to get thread", http.StatusBadRequest)
 			log.Printf("GetThread: %v", err)
 			return
@@ -675,6 +691,10 @@ func main() {
 		})
 	})
 
+	r.NotFound(func(w http.ResponseWriter, r *http.Request) {
+		views.NotFound().Render(r.Context(), w)
+	})
+
 	// -----------------
 
 	// -----------------

web/views/404.templ

@@ -0,0 +1,9 @@
+package views
+
+templ NotFound() {
+	<div class="container not-found">
+		<h1>404</h1>
+		<p>Comfychan couldn’t find that page.</p>
+		<img src="/static/media/comfy-404.png" alt="404 mascot"/>
+	</div>
+}