fix(react-compiler): optimize components declared with arrow function and implicit return and compilationMode: 'infer'

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Program.ts

@@ -963,6 +963,10 @@ function returnsNonNode(
     t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
   >,
 ): boolean {
+  if (node.type === 'ArrowFunctionExpression' && node.node.body.type === 'JSXElement') {
+    return false
+  }
+
   let hasReturn = false;
   let returnsNonNode = false;
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/arrow-function-with-implicit-return.expect.md

@@ -0,0 +1,29 @@
+
+## Input
+
+```javascript
+// @compilationMode(infer)
+const Test = () => <div />;
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @compilationMode(infer)
+const Test = () => {
+  const $ = _c(1);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = <div />;
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  return t0;
+};
+
+```
+
+### Eval output
+(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/arrow-function-with-implicit-return.js

@@ -0,0 +1,2 @@
+// @compilationMode(infer)
+const Test = () => <div />;