From b84f8e9234df47903e6bd90334e047d9ea32358f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Ribaudo?= <nicolo.ribaudo@gmail.com>
Date: Mon, 14 Aug 2017 17:11:05 +0200
Subject: [PATCH] Don't use _possibleConstructorReturn inside arrow functions
 (#6103)

Arrow functions can't be entrly skipped while traversing because this
references inside of them needs to be transformed, so I added a check
which prevents return statements inside arrow functions from being
saved for the transformation.

Fixes #5817 (regression)
---
 .../babel-helper-replace-supers/src/index.js  |  4 +++-
 .../test/fixtures/regression/5817/actual.js   |  8 +++++++
 .../test/fixtures/regression/5817/exec.js     | 16 +++++++++++++
 .../test/fixtures/regression/5817/expected.js | 24 +++++++++++++++++++
 4 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/exec.js
 create mode 100644 packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/expected.js

diff --git a/packages/babel-helper-replace-supers/src/index.js b/packages/babel-helper-replace-supers/src/index.js
index 6af12830dc..dff7328e68 100644
--- a/packages/babel-helper-replace-supers/src/index.js
+++ b/packages/babel-helper-replace-supers/src/index.js
@@ -53,7 +53,9 @@ const visitor = {
   },
 
   ReturnStatement(path, state) {
-    state.returns.push(path);
+    if (!path.getFunctionParent().isArrowFunctionExpression()) {
+      state.returns.push(path);
+    }
   },
 
   ThisExpression(path, state) {
diff --git a/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/actual.js b/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/actual.js
new file mode 100644
index 0000000000..b4ffadfbba
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/actual.js
@@ -0,0 +1,8 @@
+class A extends B {
+  constructor() {
+    super();
+
+    this.arrow1 = (x) => { return x; };
+    this.arrow2 = (x) => x;
+  }
+}
diff --git a/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/exec.js b/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/exec.js
new file mode 100644
index 0000000000..16c12bc3c2
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/exec.js
@@ -0,0 +1,16 @@
+// https://github.com/babel/babel/issues/5817
+
+class Parent {}
+
+class Table extends Parent {
+  constructor() {
+    super();
+    this.returnParam = (param) => {
+      return param;
+    }
+  }
+}
+
+const table = new Table();
+
+assert(table.returnParam(false) === false);
diff --git a/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/expected.js b/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/expected.js
new file mode 100644
index 0000000000..15d9c7f2a5
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-classes/test/fixtures/regression/5817/expected.js
@@ -0,0 +1,24 @@
+"use strict";
+
+var A = function (_B) {
+  babelHelpers.inherits(A, _B);
+
+  function A() {
+    var _this;
+
+    babelHelpers.classCallCheck(this, A);
+    _this = babelHelpers.possibleConstructorReturn(this, (A.__proto__ || Object.getPrototypeOf(A)).call(this));
+
+    _this.arrow1 = function (x) {
+      return x;
+    };
+
+    _this.arrow2 = function (x) {
+      return x;
+    };
+
+    return _this;
+  }
+
+  return A;
+}(B);