From a815a4955beac675f0aadc050f840c57b80c659a Mon Sep 17 00:00:00 2001
From: MO <fengzilong1992@gmail.com>
Date: Mon, 16 May 2022 00:47:18 +0800
Subject: [PATCH] fix: cannot remove var declaration after return

---
 lib/index.js | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/lib/index.js b/lib/index.js
index c9d5f55..6218eb0 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -560,16 +560,18 @@ module.exports = function (_ref) {
       var paths = path.get("body");
 
       var purge = false;
+      var completionPath = null;
 
       for (var i = 0; i < paths.length; i++) {
         var p = paths[i];
 
         if (!purge && p.isCompletionStatement()) {
           purge = true;
+          completionPath = p;
           continue;
         }
 
-        if (purge && !canExistAfterCompletion(p)) {
+        if (purge && (!canExistAfterCompletion(p) || canSafelyRemoved(p, completionPath))) {
           removeOrVoid(p);
         }
       }
@@ -1387,6 +1389,35 @@ module.exports = function (_ref) {
   function canExistAfterCompletion(path) {
     return path.isFunctionDeclaration() || path.isVariableDeclaration({ kind: "var" });
   }
+  
+  function canSafelyRemoved(path, completionPath) {
+    if (
+      completionPath &&
+      path.isVariableDeclaration({ kind: 'var' }) &&
+      completionPath.isReturnStatement()
+    ) {
+      var completionEnd = completionPath.node.end;
+
+      return path.node.declarations.every(function (decl) {
+        var name = decl.id.name || '';
+        var binding = path.scope.getBinding(name);
+
+        if (!binding) {
+          return false;
+        }
+
+        if (binding.referencePaths.length === 0) {
+          return true;
+        }
+
+        return binding.referencePaths.every(function (refPath) {
+          return refPath.node.start > completionEnd;
+        });
+      });
+    }
+
+    return false;
+  }
 
   function getLabel(name, _path) {
     var label = void 0,
@@ -1420,4 +1451,4 @@ module.exports = function (_ref) {
     }
     return t.sequenceExpression(result);
   }
-};
\ No newline at end of file
+};