[compiler] Add todo fixtures for local reassignment in an async callback

ghstack-source-id: eca878f62a2149af76a72b59acd1820d0df86f30
Pull Request resolved: #30109

Author: josephsavona

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo.invalid-reassign-local-variable-in-async-callback.expect.md

@@ -0,0 +1,58 @@
+
+## Input
+
+```javascript
+function Component() {
+  let value = null;
+  const reassign = async () => {
+    await foo().then((result) => {
+      // Reassigning a local variable in an async function is *always* mutating
+      // after render, so this should error regardless of where this ends up
+      // getting called
+      value = result;
+    });
+  };
+
+  const onClick = async () => {
+    await reassign();
+  };
+  return <div onClick={onClick}>Click</div>;
+}
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+function Component() {
+  const $ = _c(2);
+  let value;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    value = null;
+    $[0] = value;
+  } else {
+    value = $[0];
+  }
+  let t0;
+  if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
+    const reassign = async () => {
+      await foo().then((result) => {
+        value = result;
+      });
+    };
+
+    const onClick = async () => {
+      await reassign();
+    };
+
+    t0 = <div onClick={onClick}>Click</div>;
+    $[1] = t0;
+  } else {
+    t0 = $[1];
+  }
+  return t0;
+}
+
+```
+      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo.invalid-reassign-local-variable-in-async-callback.js

@@ -0,0 +1,16 @@
+function Component() {
+  let value = null;
+  const reassign = async () => {
+    await foo().then((result) => {
+      // Reassigning a local variable in an async function is *always* mutating
+      // after render, so this should error regardless of where this ends up
+      // getting called
+      value = result;
+    });
+  };
+
+  const onClick = async () => {
+    await reassign();
+  };
+  return <div onClick={onClick}>Click</div>;
+}

compiler/packages/snap/src/SproutTodoFilter.ts

@@ -487,6 +487,7 @@ const skipFilter = new Set([
   "todo.invalid-reassign-local-variable-in-jsx-callback",
   "todo.invalid-reassign-local-variable-in-hook-argument",
   "todo.invalid-reassign-local-variable-in-effect",
+  "todo.invalid-reassign-local-variable-in-async-callback",
 
   // bugs
   "bug-invalid-hoisting-functionexpr",