From fc3604301983d8adcd1b5c4b8dce4ece48d4f615 Mon Sep 17 00:00:00 2001
From: Joe Savona <joesavona@fb.com>
Date: Thu, 14 Dec 2023 12:05:25 -0800
Subject: [PATCH] Fixture for pruning unmemoized nonreactive deps

Adds a fixture for our existing behavior that reactive scope dependencies
exclude values which are non-reactive. The idea is that regardless of whether
the value may actually get recreated over time or not, a "nonreactive" value
cannot semantically change and therefore we can ignore changes in its pointer
address.
---
 ...pendency-is-pruned-as-dependency.expect.md | 55 +++++++++++++++++++
 ...tive-dependency-is-pruned-as-dependency.js | 17 ++++++
 2 files changed, 72 insertions(+)
 create mode 100644 compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/unmemoized-nonreactive-dependency-is-pruned-as-dependency.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/unmemoized-nonreactive-dependency-is-pruned-as-dependency.js

diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/unmemoized-nonreactive-dependency-is-pruned-as-dependency.expect.md b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/unmemoized-nonreactive-dependency-is-pruned-as-dependency.expect.md
new file mode 100644
index 0000000000..221790fc43
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/unmemoized-nonreactive-dependency-is-pruned-as-dependency.expect.md
@@ -0,0 +1,55 @@
+
+## Input
+
+```javascript
+import { mutate, useNoAlias } from "shared-runtime";
+
+function Component(props) {
+  // Here `x` cannot be memoized bc its mutable range spans a hook call:
+  const x = [];
+  useNoAlias();
+  mutate(x);
+
+  // However, `x` is non-reactive. It cannot semantically change, so we
+  // exclude it as a dependency of the JSX element:
+  return <div>{x}</div>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 42 }],
+};
+
+```
+
+## Code
+
+```javascript
+import { unstable_useMemoCache as useMemoCache } from "react";
+import { mutate, useNoAlias } from "shared-runtime";
+
+function Component(props) {
+  const $ = useMemoCache(1);
+
+  const x = [];
+  useNoAlias();
+  mutate(x);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = <div>{x}</div>;
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  return t0;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 42 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div></div>
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/unmemoized-nonreactive-dependency-is-pruned-as-dependency.js b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/unmemoized-nonreactive-dependency-is-pruned-as-dependency.js
new file mode 100644
index 0000000000..d2d39122a8
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/unmemoized-nonreactive-dependency-is-pruned-as-dependency.js
@@ -0,0 +1,17 @@
+import { mutate, useNoAlias } from "shared-runtime";
+
+function Component(props) {
+  // Here `x` cannot be memoized bc its mutable range spans a hook call:
+  const x = [];
+  useNoAlias();
+  mutate(x);
+
+  // However, `x` is non-reactive. It cannot semantically change, so we
+  // exclude it as a dependency of the JSX element:
+  return <div>{x}</div>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 42 }],
+};