From 0ae7e9f4f5107ee37364fa385b040f16182b3f26 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gr=C3=A9goire=20Geis?= <git@gregoirege.is>
Date: Sat, 26 Jan 2019 14:56:51 +0100
Subject: [PATCH 1/3] @babel/traverse: Fix NodePath.getData

Currently, if the obtained value is `false`, it will be replaced by the given default value, which is invalid. This makes sure that we only set the default value when the value is `undefined`, instead of falsy.
---
 packages/babel-traverse/src/path/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-traverse/src/path/index.js b/packages/babel-traverse/src/path/index.js
index 506a25e95ded..abc268453cf3 100644
--- a/packages/babel-traverse/src/path/index.js
+++ b/packages/babel-traverse/src/path/index.js
@@ -116,7 +116,7 @@ export default class NodePath {
 
   getData(key: string, def?: any): any {
     let val = this.data[key];
-    if (!val && def) val = this.data[key] = def;
+    if (val === undefined && def) val = this.data[key] = def;
     return val;
   }
 

From 196b24d52a554eee3e1368c3ea7e907c3ba93a08 Mon Sep 17 00:00:00 2001
From: Daniel Tschinder <daniel@tschinder.de>
Date: Tue, 26 Mar 2019 16:03:39 -0700
Subject: [PATCH 2/3] Add test and fix object protoype

---
 packages/babel-traverse/src/path/index.js  |  2 +-
 packages/babel-traverse/test/path/index.js | 37 ++++++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 packages/babel-traverse/test/path/index.js

diff --git a/packages/babel-traverse/src/path/index.js b/packages/babel-traverse/src/path/index.js
index abc268453cf3..bbb2ebbd7bff 100644
--- a/packages/babel-traverse/src/path/index.js
+++ b/packages/babel-traverse/src/path/index.js
@@ -28,7 +28,7 @@ export default class NodePath {
     this.parent = parent;
     this.hub = hub;
     this.contexts = [];
-    this.data = {};
+    this.data = Object.create(null);
     this.shouldSkip = false;
     this.shouldStop = false;
     this.removed = false;
diff --git a/packages/babel-traverse/test/path/index.js b/packages/babel-traverse/test/path/index.js
new file mode 100644
index 000000000000..400cfe1382a9
--- /dev/null
+++ b/packages/babel-traverse/test/path/index.js
@@ -0,0 +1,37 @@
+import { NodePath } from "../../lib";
+
+describe("NodePath", () => {
+  describe("setData/getData", () => {
+    it("can set default value", function() {
+      const path = new NodePath({}, {});
+
+      expect(path.getData("foo", "test")).toBe("test");
+    });
+    it("can set false", function() {
+      const path = new NodePath({}, {});
+      path.setData("foo", false);
+
+      expect(path.getData("foo", true)).toBe(false);
+    });
+
+    it("can set true", function() {
+      const path = new NodePath({}, {});
+      path.setData("foo", true);
+
+      expect(path.getData("foo", false)).toBe(true);
+    });
+
+    it("can set null", function() {
+      const path = new NodePath({}, {});
+      path.setData("foo", null);
+
+      expect(path.getData("foo", true)).toBe(null);
+    });
+
+    it("does not use object base properties", function() {
+      const path = new NodePath({}, {});
+
+      expect(path.getData("__proto__", "test")).toBe("test");
+    });
+  });
+});

From 16909beb110a9e18d44f45a79b33a97e3b5ebc23 Mon Sep 17 00:00:00 2001
From: Daniel Tschinder <daniel@tschinder.de>
Date: Tue, 26 Mar 2019 16:06:28 -0700
Subject: [PATCH 3/3] Allow false as default value

---
 packages/babel-traverse/src/path/index.js  |  2 +-
 packages/babel-traverse/test/path/index.js | 16 +++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/packages/babel-traverse/src/path/index.js b/packages/babel-traverse/src/path/index.js
index bbb2ebbd7bff..1fd58461477b 100644
--- a/packages/babel-traverse/src/path/index.js
+++ b/packages/babel-traverse/src/path/index.js
@@ -116,7 +116,7 @@ export default class NodePath {
 
   getData(key: string, def?: any): any {
     let val = this.data[key];
-    if (val === undefined && def) val = this.data[key] = def;
+    if (val === undefined && def !== undefined) val = this.data[key] = def;
     return val;
   }
 
diff --git a/packages/babel-traverse/test/path/index.js b/packages/babel-traverse/test/path/index.js
index 400cfe1382a9..5758a13cf838 100644
--- a/packages/babel-traverse/test/path/index.js
+++ b/packages/babel-traverse/test/path/index.js
@@ -2,33 +2,39 @@ import { NodePath } from "../../lib";
 
 describe("NodePath", () => {
   describe("setData/getData", () => {
-    it("can set default value", function() {
+    it("can set default value", () => {
       const path = new NodePath({}, {});
 
       expect(path.getData("foo", "test")).toBe("test");
     });
-    it("can set false", function() {
+    it("can set false", () => {
       const path = new NodePath({}, {});
       path.setData("foo", false);
 
       expect(path.getData("foo", true)).toBe(false);
     });
 
-    it("can set true", function() {
+    it("can set true", () => {
       const path = new NodePath({}, {});
       path.setData("foo", true);
 
       expect(path.getData("foo", false)).toBe(true);
     });
 
-    it("can set null", function() {
+    it("can set null", () => {
       const path = new NodePath({}, {});
       path.setData("foo", null);
 
       expect(path.getData("foo", true)).toBe(null);
     });
 
-    it("does not use object base properties", function() {
+    it("can use false as default", () => {
+      const path = new NodePath({}, {});
+
+      expect(path.getData("foo", false)).toBe(false);
+    });
+
+    it("does not use object base properties", () => {
       const path = new NodePath({}, {});
 
       expect(path.getData("__proto__", "test")).toBe("test");