From 5fc610efb373e2f753c3b0c6c2645f2aa73a2742 Mon Sep 17 00:00:00 2001
From: Joe Savona <joesavona@fb.com>
Date: Mon, 12 May 2025 11:56:33 -0700
Subject: [PATCH] [compiler] avoid empty switch case bodies

[ghstack-poisoned]
---
 .../src/ReactiveScopes/CodegenReactiveFunction.ts |  2 +-
 ...lock-scoping-switch-variable-scoping.expect.md |  3 +--
 .../fixtures/compiler/dominator.expect.md         |  3 +--
 .../fixtures/compiler/reverse-postorder.expect.md |  6 ++----
 .../fixtures/compiler/ssa-switch.expect.md        |  3 +--
 .../compiler/switch-with-fallthrough.expect.md    | 15 +++++----------
 6 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/CodegenReactiveFunction.ts b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/CodegenReactiveFunction.ts
index 33a124dcec6e2..39b2f1489809f 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/CodegenReactiveFunction.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/CodegenReactiveFunction.ts
@@ -1183,7 +1183,7 @@ function codegenTerminal(
               ? codegenPlaceToExpression(cx, case_.test)
               : null;
           const block = codegenBlock(cx, case_.block!);
-          return t.switchCase(test, [block]);
+          return t.switchCase(test, block.body.length === 0 ? [] : [block]);
         }),
       );
     }
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/block-scoping-switch-variable-scoping.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/block-scoping-switch-variable-scoping.expect.md
index d5bf094ef4ff9..a225812dbd306 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/block-scoping-switch-variable-scoping.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/block-scoping-switch-variable-scoping.expect.md
@@ -50,8 +50,7 @@ function Component(props) {
       console.log(handlers.value);
       break bb0;
     }
-    default: {
-    }
+    default:
   }
 
   t0 = handlers;
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dominator.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dominator.expect.md
index e878d4fb7f825..508a7b62581d7 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dominator.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dominator.expect.md
@@ -67,8 +67,7 @@ function Component(props) {
     case "b": {
       break bb1;
     }
-    case "c": {
-    }
+    case "c":
     default: {
       x = 6;
     }
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/reverse-postorder.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/reverse-postorder.expect.md
index c0ff0f7e7db78..98f2cd2190c20 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/reverse-postorder.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/reverse-postorder.expect.md
@@ -50,10 +50,8 @@ function Component(props) {
       case 1: {
         break bb0;
       }
-      case 2: {
-      }
-      default: {
-      }
+      case 2:
+      default:
     }
   } else {
     if (props.cond2) {
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/ssa-switch.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/ssa-switch.expect.md
index 4796fbdcc2bcf..48a765d3f3631 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/ssa-switch.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/ssa-switch.expect.md
@@ -41,8 +41,7 @@ function foo() {
     case 2: {
       break bb0;
     }
-    default: {
-    }
+    default:
   }
 }
 
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/switch-with-fallthrough.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/switch-with-fallthrough.expect.md
index c54631092c0ac..6fd911c432716 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/switch-with-fallthrough.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/switch-with-fallthrough.expect.md
@@ -43,22 +43,17 @@ export const FIXTURE_ENTRYPOINT = {
 ```javascript
 function foo(x) {
   bb0: switch (x) {
-    case 0: {
-    }
-    case 1: {
-    }
+    case 0:
+    case 1:
     case 2: {
       break bb0;
     }
     case 3: {
       break bb0;
     }
-    case 4: {
-    }
-    case 5: {
-    }
-    default: {
-    }
+    case 4:
+    case 5:
+    default:
   }
 }