From 8e80f8bd72519a00ccc2c7ef364a1ed5b3063db3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Ribaudo?= <nicolo.ribaudo@gmail.com>
Date: Fri, 25 Nov 2022 10:30:54 +0100
Subject: [PATCH] Fix block scoped vars shadowing globals

---
 .../src/index.ts                              |  1 +
 .../general/block-not-shadow-global/input.js  | 15 ++++++++++
 .../general/block-not-shadow-global/output.js | 28 +++++++++++++++++++
 .../exec.js                                   |  0
 .../input.js                                  |  0
 .../output.js                                 |  0
 6 files changed, 44 insertions(+)
 create mode 100644 packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-global/input.js
 create mode 100644 packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-global/output.js
 rename packages/babel-plugin-transform-block-scoping/test/fixtures/general/{block-outer-variable => block-not-shadow-outer-variable}/exec.js (100%)
 rename packages/babel-plugin-transform-block-scoping/test/fixtures/general/{block-outer-variable => block-not-shadow-outer-variable}/input.js (100%)
 rename packages/babel-plugin-transform-block-scoping/test/fixtures/general/{block-outer-variable => block-not-shadow-outer-variable}/output.js (100%)

diff --git a/packages/babel-plugin-transform-block-scoping/src/index.ts b/packages/babel-plugin-transform-block-scoping/src/index.ts
index 0a2632bce2b8..9f664f3efc2f 100644
--- a/packages/babel-plugin-transform-block-scoping/src/index.ts
+++ b/packages/babel-plugin-transform-block-scoping/src/index.ts
@@ -202,6 +202,7 @@ function transformBlockScopedVariable(
         // a nested scope and thus we don't need to assume that it
         // may be declared (but not registered yet) in an upper one.
         blockScope.parent.hasBinding(name, { noUids: true }) ||
+        blockScope.parent.hasGlobal(name) ||
         (isProgramScope && varScope.hasGlobal(name))
       ) {
         newName = blockScope.generateUid(name);
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-global/input.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-global/input.js
new file mode 100644
index 000000000000..d0d3db172019
--- /dev/null
+++ b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-global/input.js
@@ -0,0 +1,15 @@
+{ a; }
+{ let a; }
+
+(function () {
+  { b; }
+  { let b; }
+})();
+
+{ c = 0; }
+{ let c; }
+
+(function () {
+  { d = 0; }
+  { let d; }
+})
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-global/output.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-global/output.js
new file mode 100644
index 000000000000..eb2ad37b81c8
--- /dev/null
+++ b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-global/output.js
@@ -0,0 +1,28 @@
+{
+  a;
+}
+{
+  var _a;
+}
+(function () {
+  {
+    b;
+  }
+  {
+    var _b;
+  }
+})();
+{
+  c = 0;
+}
+{
+  var _c;
+}
+(function () {
+  {
+    d = 0;
+  }
+  {
+    var _d;
+  }
+});
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-outer-variable/exec.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-outer-variable/exec.js
similarity index 100%
rename from packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-outer-variable/exec.js
rename to packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-outer-variable/exec.js
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-outer-variable/input.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-outer-variable/input.js
similarity index 100%
rename from packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-outer-variable/input.js
rename to packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-outer-variable/input.js
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-outer-variable/output.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-outer-variable/output.js
similarity index 100%
rename from packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-outer-variable/output.js
rename to packages/babel-plugin-transform-block-scoping/test/fixtures/general/block-not-shadow-outer-variable/output.js