Merge pull request #6156 from jridgewell/pr/5502

Fix overshadowing local binding

packages/babel-plugin-check-es2015-constants/test/fixtures/general/shadowing-function-declaration/actual.js

@@ -0,0 +1,3 @@
+function B() {
+  const B = 1;
+}

packages/babel-plugin-check-es2015-constants/test/fixtures/general/shadowing-function-declaration/expected.js

@@ -0,0 +1,3 @@
+function B() {
+  var B = 1;
+}

packages/babel-plugin-check-es2015-constants/test/fixtures/general/shadowing-function-expression/actual.js

@@ -0,0 +1,3 @@
+(function B() {
+  const B = 1;
+});

packages/babel-plugin-check-es2015-constants/test/fixtures/general/shadowing-function-expression/expected.js

@@ -0,0 +1,3 @@
+(function B() {
+  var B = 1;
+});

packages/babel-plugin-transform-es2015-block-scoping/test/fixtures/general/issue-4946/actual.js

@@ -0,0 +1,3 @@
+(function foo() {
+  let foo = true;
+});

packages/babel-plugin-transform-es2015-block-scoping/test/fixtures/general/issue-4946/expected.js

@@ -0,0 +1,3 @@
+(function foo() {
+  var foo = true;
+});

packages/babel-traverse/src/scope/index.js

@@ -346,6 +346,10 @@ export default class Scope {
     // ignore parameters
     if (kind === "param") return;
 
+    // Ignore existing binding if it's the name of the current function or
+    // class expression
+    if (local.kind === "local") return;
+
     // ignore hoisted functions if there's also a local let
     if (kind === "hoisted" && local.kind === "let") return;
 
@@ -519,6 +523,7 @@ export default class Scope {
     for (const name in ids) {
       for (const id of (ids[name]: Array<Object>)) {
         let local = this.getOwnBinding(name);
+
         if (local) {
           // same identifier so continue safely as we're likely trying to register it
           // multiple times

packages/babel-traverse/test/fixtures/regression/constant-shadows-function-name/actual.js

@@ -0,0 +1,8 @@
+let obj = {
+  foo: function foo() {
+    let foo = true;
+    console.log('foo ran');
+  }
+};
+
+obj.foo();

packages/babel-traverse/test/fixtures/regression/constant-shadows-function-name/expected.js

@@ -0,0 +1,7 @@
+let obj = {
+  foo: function foo() {
+    let foo = true;
+    console.log('foo ran');
+  }
+};
+obj.foo();