From 1f95f2eae232b0b321f124618c9995b5b7f287e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <i@jhuang.me>
Date: Thu, 15 Aug 2019 17:10:07 -0400
Subject: [PATCH] fix: should not remove let binding even it is wrapped in
 closure

Fixes #10339
---
 .../src/index.js                                 |  4 +---
 .../test/fixtures/general/issue-10339/input.js   |  4 ++++
 .../fixtures/general/issue-10339/options.json    |  3 +++
 .../test/fixtures/general/issue-10339/output.js  | 16 ++++++++++++++++
 4 files changed, 24 insertions(+), 3 deletions(-)
 create mode 100644 packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/input.js
 create mode 100644 packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/options.json
 create mode 100644 packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/output.js

diff --git a/packages/babel-plugin-transform-block-scoping/src/index.js b/packages/babel-plugin-transform-block-scoping/src/index.js
index 50c254c848a8..35b8c3704556 100644
--- a/packages/babel-plugin-transform-block-scoping/src/index.js
+++ b/packages/babel-plugin-transform-block-scoping/src/index.js
@@ -453,9 +453,7 @@ class BlockScoping {
       if (binding.kind === "let" || binding.kind === "const") {
         binding.kind = "var";
 
-        if (wrappedInClosure) {
-          scope.removeBinding(ref.name);
-        } else {
+        if (!wrappedInClosure) {
           scope.moveBindingTo(ref.name, parentScope);
         }
       }
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/input.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/input.js
new file mode 100644
index 000000000000..39b916698335
--- /dev/null
+++ b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/input.js
@@ -0,0 +1,4 @@
+for (const {foo, ...bar} of {}) {
+  () => foo;
+  bar;
+}
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/options.json b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/options.json
new file mode 100644
index 000000000000..d829970edd1b
--- /dev/null
+++ b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-block-scoping", ["proposal-object-rest-spread", { "loose": true }]]
+}
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/output.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/output.js
new file mode 100644
index 000000000000..397561aef9f6
--- /dev/null
+++ b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/output.js
@@ -0,0 +1,16 @@
+function _objectWithoutPropertiesLoose(source, excluded) { if (source == null) return {}; var target = {}; var sourceKeys = Object.keys(source); var key, i; for (i = 0; i < sourceKeys.length; i++) { key = sourceKeys[i]; if (excluded.indexOf(key) >= 0) continue; target[key] = source[key]; } return target; }
+
+var _loop = function (foo, bar) {
+  () => foo;
+
+  bar;
+};
+
+for (var _ref of {}) {
+  var {
+    foo
+  } = _ref,
+      bar = _objectWithoutPropertiesLoose(_ref, ["foo"]);
+
+  _loop(foo, bar);
+}