fix: handled if fn is undefined

Author: baseballyama

src/rules/no-store-async.ts

@@ -21,7 +21,9 @@ export default createRule("no-store-async", {
       Program() {
         for (const { node } of extractStoreReferences(context)) {
           const [, fn] = node.arguments
-          if (fn.type !== "ArrowFunctionExpression" || !fn.async) continue
+          if (!fn || fn.type !== "ArrowFunctionExpression" || !fn.async) {
+            continue
+          }
 
           const start = fn.loc?.start ?? { line: 1, column: 0 }
           context.report({

tests/fixtures/rules/no-store-async/valid/test01-input.js

@@ -3,9 +3,12 @@ import { writable, readable, derived } from "svelte/store"
 const w1 = writable(false, () => {
   /** do nothing */
 })
+const w2 = writable(false)
 const r1 = readable(false, () => {
   /** do nothing */
 })
+const r2 = readable(false)
 const d1 = derived(a1, ($a1) => {
   /** do nothing */
 })
+const d2 = derived(a1)