Fix arrow transformation when arguments is defined as variable

packages/babel-core/test/fixtures/transformation/misc/regression-2364/output.js

@@ -1,7 +1,9 @@
 function wrapper(fn) {
   return function () {
+    var _arguments = arguments;
+
     var _loop = function () {
-      var val = fn(...arguments);
+      var val = fn(..._arguments);
       return {
         v: val.test(function () {
           console.log(val);

packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/arguments-global-undeclared/input.js

@@ -0,0 +1,9 @@
+function fn() {
+  var foo = () => {
+    return arguments;
+  };
+}
+
+var bar = () => arguments;
+
+var baz = () => () => arguments;

packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/arguments-global-undeclared/output.js

@@ -0,0 +1,19 @@
+var _arguments2 = typeof arguments === "undefined" ? void 0 : arguments;
+
+function fn() {
+  var _arguments = arguments;
+
+  var foo = function () {
+    return _arguments;
+  };
+}
+
+var bar = function () {
+  return _arguments2;
+};
+
+var baz = function () {
+  return function () {
+    return _arguments2;
+  };
+};

packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/arguments-global-var/input.js

@@ -0,0 +1,10 @@
+var arguments = 1;
+function fn() {
+  var foo = () => {
+    return arguments;
+  };
+}
+
+var bar = () => arguments;
+
+var baz = () => () => arguments;

packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/arguments-global-var/output.js

@@ -0,0 +1,19 @@
+var _arguments2 = 1;
+
+function fn() {
+  var _arguments = _arguments2;
+
+  var foo = function () {
+    return _arguments;
+  };
+}
+
+var bar = function () {
+  return _arguments2;
+};
+
+var baz = function () {
+  return function () {
+    return _arguments2;
+  };
+};

packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/arguments/input.js

@@ -64,14 +64,6 @@ function nine() {
 }
 nine();
 
-var arguments = 1;
-function ten() {
-  var foo = () => {
-    return arguments;
-  };
-}
-ten();
-
 var eleven = () => {
   var arguments = 2;
   return function () {

packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/arguments/output.js

@@ -1,10 +1,8 @@
-var _arguments4 = arguments;
-
 function one() {
-  var _arguments2 = arguments;
+  var _arguments = arguments;
 
   var inner = function () {
-    return _arguments2;
+    return _arguments;
   };
 
   return [].slice.call(inner());
@@ -13,13 +11,17 @@ function one() {
 one(1, 2);
 
 function two() {
+  var _arguments2 = arguments;
+
   var inner = function () {
-    return _arguments;
+    return _arguments2;
   };
 
   var another = function () {
+    var _arguments3 = arguments;
+
     var inner2 = function () {
-      return _arguments;
+      return _arguments3;
     };
   };
 
@@ -29,8 +31,10 @@ function two() {
 two(1, 2);
 
 function three() {
+  var _arguments4 = arguments;
+
   var fn = function () {
-    return _arguments[0] + "bar";
+    return _arguments4[0] + "bar";
   };
 
   return fn();
@@ -39,8 +43,10 @@ function three() {
 three("foo");
 
 function four() {
+  var _arguments5 = arguments;
+
   var fn = function () {
-    return _arguments[0].foo + "bar";
+    return _arguments5[0].foo + "bar";
   };
 
   return fn();
@@ -65,7 +71,7 @@ five({
 function six(obj) {
   var fn = function () {
     var fn2 = function () {
-      return _arguments[0];
+      return arguments[0];
     };
 
     return fn2("foobar");
@@ -77,55 +83,45 @@ function six(obj) {
 six();
 
 var seven = function () {
-  var arguments = 1;
-  return arguments;
+  var _arguments6 = 1;
+  return _arguments6;
 };
 
 seven();
 
 var eight = function () {
-  var _arguments3 = 1;
+  var _arguments7 = 1;
   return function () {
-    return _arguments4;
+    return _arguments7;
   };
 };
 
 eight();
 
 function nine() {
-  var _arguments6 = arguments;
-  var _arguments5 = 1;
+  var _arguments8 = 1;
 
   var foo = function () {
-    return _arguments6;
+    return _arguments8;
   };
 }
 
 nine();
-var _arguments = 1;
-
-function ten() {
-  var foo = function () {
-    return _arguments;
-  };
-}
-
-ten();
 
 var eleven = function () {
-  var _arguments7 = 2;
+  var arguments = 2;
   return function () {
-    var _arguments8 = arguments;
+    var _arguments9 = arguments;
     return function () {
-      return _arguments8;
+      return _arguments9;
     };
   };
 };
 
 eleven()(1, 2, 3)();
 
 var twelve = function () {
-  var _arguments9 = 2;
+  var arguments = 2;
   return class {
     m() {
       var _arguments10 = arguments;

packages/babel-traverse/src/path/conversion.ts

@@ -231,9 +231,22 @@ function hoistFunctionEnvironment(
 
   // Convert all "arguments" references in the arrow to point at the alias.
   if (argumentsPaths.length > 0) {
-    const argumentsBinding = getBinding(thisEnvFn, "arguments", () =>
-      t.identifier("arguments"),
-    );
+    const argumentsBinding = getBinding(thisEnvFn, "arguments", () => {
+      const args = () => t.identifier("arguments");
+      if (thisEnvFn.scope.path.isProgram()) {
+        return t.conditionalExpression(
+          t.binaryExpression(
+            "===",
+            t.unaryExpression("typeof", args()),
+            t.stringLiteral("undefined"),
+          ),
+          thisEnvFn.scope.buildUndefinedNode(),
+          args(),
+        );
+      } else {
+        return args();
+      }
+    });
 
     argumentsPaths.forEach(argumentsChild => {
       const argsRef = t.identifier(argumentsBinding);
@@ -586,17 +599,20 @@ function getScopeInformation(fnPath) {
       if (child.get("object").isSuper()) superProps.push(child);
     },
     ReferencedIdentifier(child) {
+      if (child.node.name !== "arguments") return;
+
       let curr = child.scope;
       do {
-        if (curr.hasOwnBinding("arguments")) return;
+        if (curr.hasOwnBinding("arguments")) {
+          curr.rename("arguments");
+          return;
+        }
         if (curr.path.isFunction() && !curr.path.isArrowFunctionExpression()) {
           break;
         }
-        if (child.node.name !== "arguments") return;
-
-        curr.rename("arguments");
-        argumentsPaths.push(child);
       } while ((curr = curr.parent));
+
+      argumentsPaths.push(child);
     },
     MetaProperty(child) {
       if (!child.get("meta").isIdentifier({ name: "new" })) return;