From 7f501f9fedfb72faf7665cf223a313e9dbb30484 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Thu, 17 Sep 2020 17:26:31 +0100
Subject: [PATCH] add tests (#4122)

---
 test/compress/concat-strings.js | 35 +++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/test/compress/concat-strings.js b/test/compress/concat-strings.js
index 5e8c512a..48b8d21c 100644
--- a/test/compress/concat-strings.js
+++ b/test/compress/concat-strings.js
@@ -238,6 +238,41 @@ concat_8: {
     expect_stdout: true
 }
 
+concat_9: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        reduce_vars: true,
+        strings: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "foo";
+        console.log(
+            12 + (34 + a),
+            null + (34 + a),
+            12 + (null + a),
+            false + (34 + a),
+            12 + (false + a),
+            "bar" + (34 + a),
+            12 + ("bar" + a)
+        );
+    }
+    expect: {
+        var a = "foo";
+        console.log(
+            "1234" + a,
+            "null34" + a,
+            "12null" + a,
+            !1 + (34 + a),
+            12 + (!1 + a),
+            "bar34" + a,
+            "12bar" + a
+        );
+    }
+    expect_stdout: true
+}
+
 issue_3689: {
     options = {
         strings: true,
-- 
2.34.1