fix: change subscriptions from set to array

Author: yyxi

packages/cassiopeia/src/index.ts

@@ -19,6 +19,7 @@ import {
   type Variables,
 } from './types'
 import { append } from './utilities/append'
+import { filter } from './utilities/filter'
 
 export function createCassiopeia(): Cassiopeia {
   const store: Store = {
@@ -28,7 +29,7 @@ export function createCassiopeia(): Cassiopeia {
     log: [],
     matcher: undefined,
     state: TypeState.Locked,
-    subscriptions: new Set(),
+    subscriptions: [],
   }
 
   const plugins: Plugin[] = []
@@ -63,9 +64,13 @@ export function createCassiopeia(): Cassiopeia {
   store.state = TypeState.None
 
   const subscribe = (subscription: Subscription): Unsubscribe => {
-    store.subscriptions.add(subscription)
+    if (!store.subscriptions.includes(subscription)) {
+      store.subscriptions.push(subscription)
+    }
 
-    return () => store.subscriptions.delete(subscription)
+    return () => {
+      filter(store.subscriptions, (value) => value !== subscription)
+    }
   }
 
   const cassiopeia: Cassiopeia = {

packages/cassiopeia/src/types.ts

@@ -70,7 +70,7 @@ export interface Store {
   iterators: Iterators
   log: Action[]
   state: TypeState
-  subscriptions: Set<Subscription>
+  subscriptions: Subscription[]
   matcher?: Matcher
 }
 

packages/cassiopeia/src/utilities/filter.ts

@@ -1,3 +1,9 @@
+/**
+ * Filters an array in-place by removing elements that don't match the predicate.
+ * Iterates backwards through the array to avoid index shifting issues when removing elements.
+ * @param array - The array to filter (mutated in place)
+ * @param predicate - Function that returns true for elements to keep
+ */
 export const filter = <T>(array: T[], predicate: (value: T) => boolean) => {
   for (let l = array.length - 1; l >= 0; l -= 1) {
     if (!predicate(array[l])) array.splice(l, 1)