From 9a58270b70a2cf575cdb74aaa6e9a0a899644e4d Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Wed, 12 Jan 2022 08:24:04 +0000
Subject: [PATCH] enhance `imports` (#5287)

---
 lib/compress.js          |  1 +
 test/compress/imports.js | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/lib/compress.js b/lib/compress.js
index b1838a1c..daebc1f8 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -459,6 +459,7 @@ Compressor.prototype.compress = function(node) {
         if (ref.in_arg && is_funarg(def)) return false;
         return all(def.orig, function(sym) {
             if (sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet) {
+                if (sym instanceof AST_SymbolImport) return true;
                 return compressor && can_varify(compressor, sym);
             }
             return !(keep_lambda && sym instanceof AST_SymbolLambda);
diff --git a/test/compress/imports.js b/test/compress/imports.js
index 0accb3ec..c9b59e93 100644
--- a/test/compress/imports.js
+++ b/test/compress/imports.js
@@ -106,6 +106,22 @@ drop_unused: {
     }
 }
 
+drop_side_effect_free: {
+    options = {
+        imports: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        import foo from "bar";
+        var a = foo;
+    }
+    expect: {
+        import "bar";
+    }
+}
+
 mangle: {
     rename = false
     mangle = {