From 1a3a515ae5f87f706b4d8fa6995ca2efd9f3cc35 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=CA=9C=C9=AA=E1=B4=8D=E1=B4=9C=CA=80=E1=B4=80=20Yu=CC=84?=
 <mail@yuhr.org>
Date: Thu, 12 Sep 2024 15:25:38 +0900
Subject: [PATCH] fix(collections): ensure `pick` doesn't generate missing
 properties as `undefined` (#5926)

---
 collections/pick.ts      |  4 +++-
 collections/pick_test.ts | 13 +++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/collections/pick.ts b/collections/pick.ts
index a443a98e8beb..c399e55624d6 100644
--- a/collections/pick.ts
+++ b/collections/pick.ts
@@ -28,5 +28,7 @@ export function pick<T extends object, K extends keyof T>(
   obj: Readonly<T>,
   keys: readonly K[],
 ): Pick<T, K> {
-  return Object.fromEntries(keys.map((k) => [k, obj[k]])) as Pick<T, K>;
+  const result = {} as Pick<T, K>;
+  for (const key of keys) if (key in obj) result[key] = obj[key];
+  return result;
 }
diff --git a/collections/pick_test.ts b/collections/pick_test.ts
index f3604a34878b..a8a5c102a555 100644
--- a/collections/pick_test.ts
+++ b/collections/pick_test.ts
@@ -14,6 +14,19 @@ Deno.test({
   },
 });
 
+Deno.test({
+  name:
+    "pick() returns a new object without properties missing in the original object",
+  fn() {
+    // deno-lint-ignore no-explicit-any
+    const obj = { a: 5, b: 6, c: 7, d: 8 } as any;
+    const picked: { a: 5; x?: 5; y?: 5 } = pick(obj, ["a", "x", "y"]);
+
+    assertEquals(picked, { a: 5 });
+    assertNotStrictEquals(picked, obj);
+  },
+});
+
 Deno.test({
   name:
     "pick() returns a new object from the provided object with the provided keys",