From 44c2791849f37e2082b080faf2677e8e56bcdba6 Mon Sep 17 00:00:00 2001
From: Logan Smyth <loganfsmyth@gmail.com>
Date: Mon, 13 Nov 2017 11:33:08 -0800
Subject: [PATCH] Expose a function for plugins to check if async plugins are
 supported by the current compilation.

---
 packages/babel-core/src/config/loading/files/configuration.js | 1 +
 packages/babel-core/src/config/option-manager.js              | 1 +
 2 files changed, 2 insertions(+)

diff --git a/packages/babel-core/src/config/loading/files/configuration.js b/packages/babel-core/src/config/loading/files/configuration.js
index 663fdcb4a7..1c44439092 100644
--- a/packages/babel-core/src/config/loading/files/configuration.js
+++ b/packages/babel-core/src/config/loading/files/configuration.js
@@ -142,6 +142,7 @@ const readConfigJS = makeStrongCache((filepath, cache) => {
       cache,
       // Expose ".env()" so people can easily get the same env that we expose using the "env" key.
       env: () => cache.using(() => getEnv()),
+      async: () => false,
     });
   } else {
     cache.forever();
diff --git a/packages/babel-core/src/config/option-manager.js b/packages/babel-core/src/config/option-manager.js
index 394f89d9f6..b9ea81c796 100644
--- a/packages/babel-core/src/config/option-manager.js
+++ b/packages/babel-core/src/config/option-manager.js
@@ -189,6 +189,7 @@ const loadDescriptor = makeWeakCache(
       const api = Object.assign(Object.create(context), {
         cache,
         env: () => cache.using(() => getEnv()),
+        async: () => false,
       });
 
       try {