From ae4dd941ba6d957c913e43cd2825ec23eb3fe75e Mon Sep 17 00:00:00 2001
From: Maximiliano Osorio <maxiosorio@gmail.com>
Date: Thu, 23 Nov 2023 11:15:57 -0300
Subject: [PATCH] fix: improve 404 error

---
 index.ts          | 9 +++++----
 src/renderHtml.ts | 8 ++++----
 src/types.ts      | 9 ++++++++-
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/index.ts b/index.ts
index 64d5211..9360f7a 100644
--- a/index.ts
+++ b/index.ts
@@ -27,11 +27,12 @@ app.get("/*", (req: Request, res: Response) => {
   req.log.info(`Request for ${uri}`);
   res.format({
     "text/html": async () => {
-      try {
-        const data = await handleQueryHtml(uri, config.sparqlQueryUrl);
+      const data = await handleQueryHtml(uri, config.sparqlQueryUrl);
+      if (data.outcomingQuads.length === 0 && data.incomingQuads.length === 0) {
+        const message = `<h1>Not Found</h1> <p>There is no data for <a href="${uri}">${uri}</a></p> <p> Endpoint: <a href="${config.sparqlQueryUrl}">${config.sparqlQueryUrl}</a></p>`;
+        return res.status(404).send(message);
+      } else {
         return res.render("results", data);
-      } catch (error) {
-        return res.status(404).send("Not Found");
       }
     },
     "application/n-quads": async () => {
diff --git a/src/renderHtml.ts b/src/renderHtml.ts
index f0523a8..d20ff6d 100644
--- a/src/renderHtml.ts
+++ b/src/renderHtml.ts
@@ -4,10 +4,10 @@ import { toPrefix } from "./utils";
 const handleQueryHtml = async (uri: string, endpoint: string) => {
   const outcomingQuads = await performQueryHtml(uri, endpoint);
   const incomingQuads = await performIncomingQueryHtml(uri, endpoint);
-  if (outcomingQuads.length === 0 && incomingQuads.length === 0) {
-    throw new Error("Not Found");
-  }
-  const title = getTitle();
+  const title =
+    outcomingQuads.length === 0 && incomingQuads.length === 0
+      ? "Not Found"
+      : getTitle();
   return {
     incomingQuads: incomingQuads,
     outcomingQuads: outcomingQuads,
diff --git a/src/types.ts b/src/types.ts
index 9a64e09..b285c46 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,3 +1,5 @@
+import type * as RDF from "@rdfjs/types";
+
 interface Config {
   sparqlQueryUrl: string;
   port: number;
@@ -10,4 +12,9 @@ interface Prefix {
   uri: string;
 }
 
-export { Config, Prefix };
+interface QueryResults {
+  quads: RDF.Quad[];
+  query: string;
+}
+
+export { Config, Prefix, QueryResults };