From 9e05168ceebfc5b54968b397ed277e26d3262559 Mon Sep 17 00:00:00 2001
From: Etienne Donneger <etienne@pinax.network>
Date: Thu, 9 May 2024 16:32:40 -0400
Subject: [PATCH] Have at least one `total_pages` in case of empty query result
 (#28)

---
 src/fetch/utils.spec.ts |  2 +-
 src/fetch/utils.ts      | 13 ++++++-------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/fetch/utils.spec.ts b/src/fetch/utils.spec.ts
index a9986a3..fe1f8f9 100644
--- a/src/fetch/utils.spec.ts
+++ b/src/fetch/utils.spec.ts
@@ -42,7 +42,7 @@ test("addMetadata pagination", () => {
     expect(last_page.meta.total_results).toBe(5 * limit);
 
     // Expect error message on beyond last page
-    expect(() => addMetadata(mock_query_reponse, limit, limit + 1)).toThrow("Requested page exceeds total pages");
+    expect(() => addMetadata(mock_query_reponse, limit, limit + 1)).toThrow(`Requested page (${limit + 1}) exceeds total pages (${limit})`);
 });
 
 test("addMetadata no pagination", () => {
diff --git a/src/fetch/utils.ts b/src/fetch/utils.ts
index 56856d4..1cbf5af 100644
--- a/src/fetch/utils.ts
+++ b/src/fetch/utils.ts
@@ -5,7 +5,7 @@ import * as prometheus from "../prometheus.js";
 interface APIError {
     status: number,
     code?: string,
-    detail?: string
+    detail?: string;
 }
 
 export function APIError(pathname: string, status: number, code?: string, detail?: string) {
@@ -13,7 +13,7 @@ export function APIError(pathname: string, status: number, code?: string, detail
         status,
         code: code ? code : "unknown",
         detail: detail ? detail : ""
-    }
+    };
 
     logger.error("<APIError>\n", api_error);
     prometheus.request_error.inc({ pathname, status });
@@ -25,12 +25,11 @@ export function toJSON(data: any, status: number = 200) {
 }
 
 export function addMetadata(response: Query<any>, req_limit?: number, req_page?: number) {
-    // TODO: Catch page number greater than total_pages and return error
     if (typeof (req_limit) !== 'undefined' && typeof (req_page) !== 'undefined') {
-        const total_pages = Math.ceil(response.rows_before_limit_at_least / req_limit);
+        const total_pages = Math.max(Math.ceil(response.rows_before_limit_at_least / req_limit), 1); // Always have a least one total page
 
         if (req_page > total_pages)
-            throw Error("Requested page exceeds total pages")
+            throw Error(`Requested page (${req_page}) exceeds total pages (${total_pages})`);
 
         return {
             data: response.data,
@@ -41,13 +40,13 @@ export function addMetadata(response: Query<any>, req_limit?: number, req_page?:
                 total_pages,
                 total_results: response.rows_before_limit_at_least
             }
-        }
+        };
     } else {
         return {
             data: response.data,
             meta: {
                 statistics: response.statistics,
             }
-        }
+        };
     }
 }
\ No newline at end of file