From b2b0b0f6c634603da6f486c12629218882c45f4a Mon Sep 17 00:00:00 2001
From: Mike Vitousek <mmvitousek@gmail.com>
Date: Tue, 13 Aug 2024 15:09:59 -0400
Subject: [PATCH] [compiler] Reordering of logical expressions

ghstack-source-id: 0f92be69d258ddfdb10e39dcbc80819557be2441
Pull Request resolved: https://github.com/facebook/react/pull/30678
---
 .../src/HIR/BuildHIR.ts                       | 15 +++++++
 .../compiler/logical-reorder.flow.expect.md   | 43 +++++++++++++++++++
 .../fixtures/compiler/logical-reorder.flow.js | 16 +++++++
 3 files changed, 74 insertions(+)
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/logical-reorder.flow.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/logical-reorder.flow.js

diff --git a/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts b/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
index b9bddff6a58b5..859f1fdc45bed 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
@@ -2837,6 +2837,21 @@ function isReorderableExpression(
         allowLocalIdentifiers,
       );
     }
+    case 'LogicalExpression': {
+      const logical = expr as NodePath<t.LogicalExpression>;
+      return (
+        isReorderableExpression(
+          builder,
+          logical.get('left'),
+          allowLocalIdentifiers,
+        ) &&
+        isReorderableExpression(
+          builder,
+          logical.get('right'),
+          allowLocalIdentifiers,
+        )
+      );
+    }
     case 'ConditionalExpression': {
       const conditional = expr as NodePath<t.ConditionalExpression>;
       return (
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/logical-reorder.flow.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/logical-reorder.flow.expect.md
new file mode 100644
index 0000000000000..e24d2c5525813
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/logical-reorder.flow.expect.md
@@ -0,0 +1,43 @@
+
+## Input
+
+```javascript
+//@flow
+
+const foo = undefined;
+
+component C(
+  ...{
+    scope = foo ?? null,
+  }: any
+) {
+  return scope;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: C,
+  params: [{scope: undefined}],
+};
+
+```
+
+## Code
+
+```javascript
+const foo = undefined;
+
+function C(t0) {
+  const { scope: t1 } = t0;
+  const scope = t1 === undefined ? (foo ?? null) : t1;
+  return scope;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: C,
+  params: [{ scope: undefined }],
+};
+
+```
+      
+### Eval output
+(kind: ok) null
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/logical-reorder.flow.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/logical-reorder.flow.js
new file mode 100644
index 0000000000000..497a1ceca1cd2
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/logical-reorder.flow.js
@@ -0,0 +1,16 @@
+//@flow
+
+const foo = undefined;
+
+component C(
+  ...{
+    scope = foo ?? null,
+  }: any
+) {
+  return scope;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: C,
+  params: [{scope: undefined}],
+};