From 344c03b2e64af9caa0e386a63476805831a8e0b0 Mon Sep 17 00:00:00 2001
From: Mestery <mestery@pm.me>
Date: Thu, 23 Sep 2021 19:51:31 +0200
Subject: [PATCH] repl: skip EmptyStatements and return result with TLA
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fixes: https://github.com/nodejs/node/issues/39932

PR-URL: https://github.com/nodejs/node/pull/40194
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
---
 lib/internal/repl/await.js                    | 36 ++++++++++---------
 .../test-repl-preprocess-top-level-await.js   |  2 ++
 2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/lib/internal/repl/await.js b/lib/internal/repl/await.js
index ba138fdfe8c8d9..ec1d0c8823e107 100644
--- a/lib/internal/repl/await.js
+++ b/lib/internal/repl/await.js
@@ -221,22 +221,26 @@ function processTopLevelAwait(src) {
     return null;
   }
 
-  const last = body.body[body.body.length - 1];
-  if (last.type === 'ExpressionStatement') {
-    // For an expression statement of the form
-    // ( expr ) ;
-    // ^^^^^^^^^^   // last
-    //   ^^^^       // last.expression
-    //
-    // We do not want the left parenthesis before the `return` keyword;
-    // therefore we prepend the `return (` to `last`.
-    //
-    // On the other hand, we do not want the right parenthesis after the
-    // semicolon. Since there can only be more right parentheses between
-    // last.expression.end and the semicolon, appending one more to
-    // last.expression should be fine.
-    state.prepend(last, 'return (');
-    state.append(last.expression, ')');
+  for (let i = body.body.length - 1; i >= 0; i--) {
+    const node = body.body[i];
+    if (node.type === 'EmptyStatement') continue;
+    if (node.type === 'ExpressionStatement') {
+      // For an expression statement of the form
+      // ( expr ) ;
+      // ^^^^^^^^^^   // node
+      //   ^^^^       // node.expression
+      //
+      // We do not want the left parenthesis before the `return` keyword;
+      // therefore we prepend the `return (` to `node`.
+      //
+      // On the other hand, we do not want the right parenthesis after the
+      // semicolon. Since there can only be more right parentheses between
+      // node.expression.end and the semicolon, appending one more to
+      // node.expression should be fine.
+      state.prepend(node, 'return (');
+      state.append(node.expression, ')');
+    }
+    break;
   }
 
   return (
diff --git a/test/parallel/test-repl-preprocess-top-level-await.js b/test/parallel/test-repl-preprocess-top-level-await.js
index 656b616b71d9e6..51b15e107f53bc 100644
--- a/test/parallel/test-repl-preprocess-top-level-await.js
+++ b/test/parallel/test-repl-preprocess-top-level-await.js
@@ -22,6 +22,8 @@ const testCases = [
     `(async () => { return (await ${surrogate}) })()` ],
   [ 'await 0;',
     '(async () => { return (await 0); })()' ],
+  [ 'await 0;;;',
+    '(async () => { return (await 0);;; })()' ],
   [ `await ${surrogate};`,
     `(async () => { return (await ${surrogate}); })()` ],
   [ `await ${surrogate};`,