From 256fcbc58f3bed051b13523fcc2603cd3169c3a1 Mon Sep 17 00:00:00 2001
From: Diogo Franco <diogomfranco@gmail.com>
Date: Sun, 19 Mar 2017 11:28:52 +0900
Subject: [PATCH] Treat "await" as an invalid identifier (#4954)

It is valid (outside `async` functions) in the "script" parse goal, but always invalid in the "module" parse goal.

Fixes #4952.
---
 .../test/fixtures/function-name/await/actual.js               | 3 +++
 .../test/fixtures/function-name/await/expected.js             | 3 +++
 packages/babel-types/src/validators.js                        | 3 +++
 packages/babel-types/test/validators.js                       | 4 ++++
 4 files changed, 13 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/await/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/await/expected.js

diff --git a/packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/await/actual.js b/packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/await/actual.js
new file mode 100644
index 0000000000..8f9c647db8
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/await/actual.js
@@ -0,0 +1,3 @@
+export {};
+
+var obj = { await: function () {} };
diff --git a/packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/await/expected.js b/packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/await/expected.js
new file mode 100644
index 0000000000..4289b26aa5
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/await/expected.js
@@ -0,0 +1,3 @@
+export {};
+
+var obj = { await: function _await() {} };
\ No newline at end of file
diff --git a/packages/babel-types/src/validators.js b/packages/babel-types/src/validators.js
index c5f25327bd..dc8143ae9d 100644
--- a/packages/babel-types/src/validators.js
+++ b/packages/babel-types/src/validators.js
@@ -167,6 +167,9 @@ export function isReferenced(node: Object, parent: Object): boolean {
 export function isValidIdentifier(name: string): boolean {
   if (typeof name !== "string" || esutils.keyword.isReservedWordES6(name, true)) {
     return false;
+  } else if (name === "await") {
+    // invalid in module, valid in script; better be safe (see #4952)
+    return false;
   } else {
     return esutils.keyword.isIdentifierNameES6(name);
   }
diff --git a/packages/babel-types/test/validators.js b/packages/babel-types/test/validators.js
index 2e7e55d085..ccc83f665b 100644
--- a/packages/babel-types/test/validators.js
+++ b/packages/babel-types/test/validators.js
@@ -26,5 +26,9 @@ suite("validators", function () {
 
       assert(t.isNodesEquivalent(parse(program), parse(program2)) === false);
     });
+
+    it("rejects 'await' as an identifier", function () {
+      assert(t.isValidIdentifier("await") === false);
+    });
   });
 });