From 17090393d5d2c9993d8f5491fa42e502a7f3c75d Mon Sep 17 00:00:00 2001
From: Mozafar Haider <mozafar@dhis2.org>
Date: Mon, 22 Jun 2026 21:22:43 +0100
Subject: [PATCH] fix: avoid redundant network request when serving cached
 query alias

---
 .../RestAPILink/fetchData.aliasing.test.ts    | 28 +++++++++++++++++++
 engine/src/links/RestAPILink/fetchData.ts     |  2 +-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/engine/src/links/RestAPILink/fetchData.aliasing.test.ts b/engine/src/links/RestAPILink/fetchData.aliasing.test.ts
index ccfaaebaf..2ff2f934f 100644
--- a/engine/src/links/RestAPILink/fetchData.aliasing.test.ts
+++ b/engine/src/links/RestAPILink/fetchData.aliasing.test.ts
@@ -113,6 +113,34 @@ describe('fetchData - query alias creation and caching', () => {
         expect(aliasCreateCalls).toBe(1)
     })
 
+    it('uses cached alias with a single fetch, not two', async () => {
+        const data = { result: 'cached' }
+        const alias1 = {
+            id: 'alias-1',
+            path: '/alias/1',
+            href: `${baseUrl}/alias/1`,
+            target: longUrl,
+        }
+
+        // Pre-populate the cache so fetchAlias is used directly
+        refs.queryAliasCache.set(longUrl, alias1)
+
+        const mockFetch = jest.fn(async (reqUrl: string) => {
+            if (reqUrl === alias1.href) {
+                return makeResponse({ body: data, status: 200 })
+            }
+            return makeResponse({ body: null, status: 500 })
+        })
+        ;(global as any).fetch = mockFetch
+
+        const result = await fetchData(longUrl, { method: 'GET' }, refs as any)
+
+        expect(result).toEqual(data)
+        // alias.href must be fetched exactly once — the first response must be returned directly
+        expect(mockFetch).toHaveBeenCalledTimes(1)
+        expect(mockFetch).toHaveBeenCalledWith(alias1.href, expect.any(Object))
+    })
+
     it('reuses cached alias until server reports it expired, then recreates and caches a new alias', async () => {
         const dataA = { result: 'A' }
         const dataB = { result: 'B' }
diff --git a/engine/src/links/RestAPILink/fetchData.ts b/engine/src/links/RestAPILink/fetchData.ts
index 5fc3481be..3f5750a5e 100644
--- a/engine/src/links/RestAPILink/fetchData.ts
+++ b/engine/src/links/RestAPILink/fetchData.ts
@@ -151,7 +151,7 @@ const fetchAlias = async (
         return createQueryAlias(alias.target, options, refs)
     }
 
-    return fetchWithContext(alias.href, options, refs)
+    return response
 }
 
 export function fetchData(