From 662d2c08fe360c8fd4001189eda2cf0e6fa1b6b1 Mon Sep 17 00:00:00 2001
From: Yarchik <spoko.dev@gmail.com>
Date: Thu, 2 Jul 2026 10:57:56 +0100
Subject: [PATCH] fix: preserve $meta direction in [field, direction] sort pair

formatSort's pairToMap wrapped the direction in an array
(prepareDirection([v[1]])) unlike every sibling converter. Scalar directions
survive the array-to-string coercion, but a $meta object does not (isMeta is
false for an array), so the documented cursor.sort(['score', { $meta:
'textScore' }]) throws Invalid sort direction while the object and deep-array
forms work. Pass the raw value through, as the other converters do.
---
 src/sort.ts            |  2 +-
 test/unit/sort.test.ts | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 test/unit/sort.test.ts

diff --git a/src/sort.ts b/src/sort.ts
index 0b239ddd494..7625937ca56 100644
--- a/src/sort.ts
+++ b/src/sort.ts
@@ -81,7 +81,7 @@ function isReadonlyArray<T>(value: any): value is readonly T[] {
 
 /** @internal */
 function pairToMap(v: readonly [string, SortDirection]): SortForCmd {
-  return new Map([[`${v[0]}`, prepareDirection([v[1]])]]);
+  return new Map([[`${v[0]}`, prepareDirection(v[1])]]);
 }
 
 /** @internal */
diff --git a/test/unit/sort.test.ts b/test/unit/sort.test.ts
new file mode 100644
index 00000000000..19669feff36
--- /dev/null
+++ b/test/unit/sort.test.ts
@@ -0,0 +1,21 @@
+import { expect } from 'chai';
+
+import { formatSort } from '../mongodb';
+
+describe('formatSort', function () {
+  context('when the sort is a [field, direction] pair', function () {
+    it('formats a numeric direction', function () {
+      expect(formatSort(['alpha', -1])).to.deep.equal(new Map([['alpha', -1]]));
+    });
+
+    it('formats a string direction', function () {
+      expect(formatSort(['alpha', 'asc'])).to.deep.equal(new Map([['alpha', 1]]));
+    });
+
+    it('preserves a $meta direction', function () {
+      expect(formatSort(['alpha', { $meta: 'textScore' }])).to.deep.equal(
+        new Map([['alpha', { $meta: 'textScore' }]])
+      );
+    });
+  });
+});