From 303293e4aada63d7f1854df2c5b3da9036f0e1b3 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Wed, 31 May 2017 01:44:29 +0800
Subject: [PATCH] fix `side_effects` on `AST_Class` (#2031)

fixes #2028
---
 lib/compress.js          |  2 +-
 test/compress/harmony.js | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/lib/compress.js b/lib/compress.js
index d1ba2986..b527557f 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -251,7 +251,7 @@ merge(Compressor.prototype, {
                     })
                 });
             }
-            if (node instanceof AST_Lambda && node !== self) {
+            if (node instanceof AST_Class || node instanceof AST_Lambda && node !== self) {
                 return node;
             }
             if (node instanceof AST_Block) {
diff --git a/test/compress/harmony.js b/test/compress/harmony.js
index f92668ab..3b772976 100644
--- a/test/compress/harmony.js
+++ b/test/compress/harmony.js
@@ -583,3 +583,39 @@ class_extends_regex: {
     }
     expect_exact: "function f(){class rx1 extends(/rx/){}}"
 }
+
+issue_2028: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        var a = {};
+        (function(x) {
+            x.X = function() {
+                return X;
+            };
+            class X {
+                static hello() {
+                    console.log("hello");
+                }
+            }
+        }(a));
+        a.X().hello();
+    }
+    expect: {
+        var a = {};
+        (function(x) {
+            x.X = function() {
+                return X;
+            };
+            class X {
+                static hello() {
+                    console.log("hello");
+                }
+            }
+        }(a));
+        a.X().hello();
+    }
+    expect_stdout: "hello"
+    node_version: ">=6"
+}