From 986c95bc09189f81f5a6a324f36195fe9bafcf47 Mon Sep 17 00:00:00 2001
From: Sathya Gunasekaran <gsathya.ceg@gmail.com>
Date: Wed, 11 Jan 2023 15:17:13 +0000
Subject: [PATCH] [hir] Add test case for incorrect memoisation of mutated
 objects

In this case, x should not be cached within the if or else blocks as it is
mutated later.
---
 .../hir/obj-mutated-after-if-else.expect.md   | 65 +++++++++++++++++++
 .../fixtures/hir/obj-mutated-after-if-else.js | 11 ++++
 2 files changed, 76 insertions(+)
 create mode 100644 compiler/forget/src/__tests__/fixtures/hir/obj-mutated-after-if-else.expect.md
 create mode 100644 compiler/forget/src/__tests__/fixtures/hir/obj-mutated-after-if-else.js

diff --git a/compiler/forget/src/__tests__/fixtures/hir/obj-mutated-after-if-else.expect.md b/compiler/forget/src/__tests__/fixtures/hir/obj-mutated-after-if-else.expect.md
new file mode 100644
index 0000000000..a963142635
--- /dev/null
+++ b/compiler/forget/src/__tests__/fixtures/hir/obj-mutated-after-if-else.expect.md
@@ -0,0 +1,65 @@
+
+## Input
+
+```javascript
+function foo(a, b, c, d) {
+  let x = someObj();
+  if (a) {
+    x = someObj();
+  } else {
+    x = someObj();
+  }
+
+  x.f = 1;
+  return x;
+}
+
+```
+
+## Code
+
+```javascript
+function foo(a, b, c, d) {
+  const $ = React.useMemoCache();
+  const x = someObj();
+  const c_0 = $[0] !== a;
+  let x$0;
+  if (c_0) {
+    x$0 = undefined;
+
+    if (a) {
+      let x$1;
+
+      if ($[2] === Symbol.for("react.memo_cache_sentinel")) {
+        x$1 = someObj();
+        $[2] = x$1;
+      } else {
+        x$1 = $[2];
+      }
+
+      x$0 = x$1;
+    } else {
+      let x$2;
+
+      if ($[3] === Symbol.for("react.memo_cache_sentinel")) {
+        x$2 = someObj();
+        $[3] = x$2;
+      } else {
+        x$2 = $[3];
+      }
+
+      x$0 = x$2;
+    }
+
+    x$0.f = 1;
+    $[0] = a;
+    $[1] = x$0;
+  } else {
+    x$0 = $[1];
+  }
+
+  return x$0;
+}
+
+```
+      
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/obj-mutated-after-if-else.js b/compiler/forget/src/__tests__/fixtures/hir/obj-mutated-after-if-else.js
new file mode 100644
index 0000000000..ed43dec122
--- /dev/null
+++ b/compiler/forget/src/__tests__/fixtures/hir/obj-mutated-after-if-else.js
@@ -0,0 +1,11 @@
+function foo(a, b, c, d) {
+  let x = someObj();
+  if (a) {
+    x = someObj();
+  } else {
+    x = someObj();
+  }
+
+  x.f = 1;
+  return x;
+}