From 4315ed5b827ff953fc108775329d4c3c18771759 Mon Sep 17 00:00:00 2001
From: Rico Kahler <ricokahler@gmail.com>
Date: Tue, 3 Jun 2025 01:23:41 -0500
Subject: [PATCH] refactor: simplify array unset logic by removing revision
 lock check

Remove the isRevisionLocked() condition from array diffing logic when
deciding between key-based vs index-based unset operations.

The revision lock check was redundant because:
- Key-based unsets are inherently safer in collaborative environments
- Revision locking doesn't change the safety characteristics of the operation
- If array items have unique keys, key-based operations should always be
  preferred regardless of whether we're targeting a specific revision
- Index-based operations are still used as fallback when items lack unique keys

This simplifies the logic to: if items have unique keys, always use key-based
unsets; otherwise fall back to index-based unsets.
---
 src/diffPatch.ts | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/diffPatch.ts b/src/diffPatch.ts
index 22d5448..696d695 100644
--- a/src/diffPatch.ts
+++ b/src/diffPatch.ts
@@ -267,21 +267,19 @@ function diffArray(
     const isSingle = itemA.length - itemB.length === 1
     const unsetItems = itemA.slice(itemB.length)
 
-    // If we're revision locked, we can safely unset ranges (eg 5:<end-of-array>).
-    // Also, if we don't have unique array keys, we can't use any better approach
-    // than array indexes. If we _do_ have unique array keys, we'll want to unset
-    // by key, as this is safer in a realtime, collaborative setting
-    if (isRevisionLocked(options) || !isUniquelyKeyed(unsetItems)) {
-      patches.push({
-        op: 'unset',
-        path: path.concat([isSingle ? itemB.length : [itemB.length, '']]),
-      })
-    } else {
+    // If we have unique array keys, we'll want to unset by key, as this is
+    // safer in a realtime, collaborative setting
+    if (isUniquelyKeyed(unsetItems)) {
       patches.push(
         ...unsetItems.map(
           (item): UnsetPatch => ({op: 'unset', path: path.concat({_key: item._key})}),
         ),
       )
+    } else {
+      patches.push({
+        op: 'unset',
+        path: path.concat([isSingle ? itemB.length : [itemB.length, '']]),
+      })
     }
   }
 
@@ -598,10 +596,6 @@ function nullifyUndefined(item: unknown, path: Path, index: number, options: Pat
   return null
 }
 
-function isRevisionLocked(options: PatchOptions): boolean {
-  return Boolean(options.ifRevisionID)
-}
-
 function yes(_: unknown) {
   return true
 }