From d5c11b294ef2257d31778609caddf9980e24e6f6 Mon Sep 17 00:00:00 2001
From: clover caruso <git@paperclover.net>
Date: Thu, 29 Jan 2026 16:56:46 -0800
Subject: [PATCH] feat: arrayFilter and useMutate args

---
 jsr.json              |  2 +-
 src/react.ts          | 13 +++++++++++++
 src/tanstack-query.ts | 22 ++++++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/jsr.json b/jsr.json
index ad9150526795d168d4f2fdc11f2ef5589fa1cca9..835a348d014e3df039d914cd2fa553a6c81c73d8 100644
--- a/jsr.json
+++ b/jsr.json
@@ -1,6 +1,6 @@
 {
   "name": "@clo/react-mutation",
-  "version": "1.0.0-beta.7",
+  "version": "1.0.0-beta.8",
   "exports": {
     ".": "./src/mod.ts",
     "./tanstack-query.ts": "./src/tanstack-query.ts",
diff --git a/src/react.ts b/src/react.ts
index 2d8dac06a9d527d9b9d6246c2e1fb0854c709eed..15caaee76e046ecc7823d371e48eacc462e5094a 100644
--- a/src/react.ts
+++ b/src/react.ts
@@ -45,6 +45,7 @@ export interface UseMutateResultBase<Args extends unknown[], Result> {
     ..._: [...args: Args, options: RunOptions<Result>]
   ) => Promise<Result>;
   clear: () => void;
+  args: Args | undefined;
 }
 
 export interface UseMutateSuccess<Result> {
@@ -175,7 +176,11 @@ class Observer<Args extends unknown[], Result> {
   run(...args: Args) {
     const mutation = this.mutation;
     if (!mutation) return;
+    const argsChanged = this.currentArgs !== args;
     this.currentArgs = args;
+    if (argsChanged && this.watched.has("args")) {
+      this.setRerender(Math.random());
+    }
     const key = mutation.key(args);
     if (key !== this.currentKey) {
       this.currentKey = key;
@@ -249,7 +254,11 @@ class Observer<Args extends unknown[], Result> {
     const args = array.slice() as Args;
     const options = args.pop() as RunOptions<Result>;
 
+    const argsChanged = this.currentArgs !== args;
     this.currentArgs = args;
+    if (argsChanged && this.watched.has("args")) {
+      this.setRerender(Math.random());
+    }
     const key = mutation.key(args);
 
     // Set up subscription if key changed
@@ -347,6 +356,10 @@ class Observer<Args extends unknown[], Result> {
       self.watched.add("isOptimisticData");
       return self.state.isOptimisticData;
     },
+    get args() {
+      self.watched.add("args");
+      return self.currentArgs ?? undefined;
+    },
   } as UseMutateResult<Args, Result>))(this);
 }
 
diff --git a/src/tanstack-query.ts b/src/tanstack-query.ts
index a4a5b0d51f0d7dff893ad7e3a0283f41b5ef8ce0..a670aa02d4651b17e578a5cc496074dfff10383d 100644
--- a/src/tanstack-query.ts
+++ b/src/tanstack-query.ts
@@ -509,6 +509,28 @@ class TanstackQueryOptimisticHelpers {
     });
   }
 
+  /**
+   * Filter items to just include items that match `filter`. This is the inverse of `arrayRemove`
+   * If the query or path doesn't exist, the updater is skipped.
+   */
+  arrayFilter<Data>(
+    queryKey: QueryKeyAndFn<Data[] | null>,
+    filter: (
+      item: Data,
+      index: number,
+    ) => boolean,
+  ) {
+    const prev = this.#get(queryKey);
+    if (!prev || !Array.isArray(prev)) return;
+
+    const newArray = prev.filter(filter);
+    this.#set(queryKey, newArray);
+    this.#onRestore(() => {
+      // TODO: splice items back in case original changed
+      this.#set(queryKey, prev);
+    });
+  }
+
   /**
    * Update items in an array that match a `filter`.
    * If the query or path doesn't exist, the updater is skipped.
-- 
2.54.0