From 88f8ce230145d1d54b79774e919abdbc34d263fe Mon Sep 17 00:00:00 2001
From: Tomasz Chmielnicki <t.chmielnicki@p-programisci.pl>
Date: Mon, 11 Aug 2025 11:41:00 +0200
Subject: [PATCH] test: Fetch keys parameter type inference

---
 test/index.test.ts | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/test/index.test.ts b/test/index.test.ts
index e6e36b1..228d6e3 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -6,7 +6,8 @@ import {
   PickKeys,
   FetchKeys,
   postprocessQuery,
-  Api
+  Api,
+  PaginatedPublicArticleList
 } from './generated/__generated-api'
 import onCreateRoute from '../src/onCreateRoute'
 
@@ -387,4 +388,14 @@ describe('API class', () => {
       }[]
     }>()
   })
+
+  it('infers array fetchKeys parameter type as const', () => {
+    const testFn = <T extends FetchKeys<PaginatedPublicArticleList>>(
+      fetchKeys: T
+    ) => fetchKeys
+
+    const returnedFetchKeys = testFn(['author'])
+    // check if array fetchKeys are inferred as ["key"], not "key"[] when passed into a function
+    expectTypeOf(returnedFetchKeys).toEqualTypeOf<['author']>()
+  })
 })