1 files changed, 43 insertions, 0 deletions
diff --git a/toolkit/jetpack/sdk/webextension.js b/toolkit/jetpack/sdk/webextension.js
new file mode 100644
index 0000000000..d1c4385e2b
--- /dev/null
+++ b/toolkit/jetpack/sdk/webextension.js
@@ -0,0 +1,43 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+module.metadata = {
+  "stability": "experimental"
+};
+
+let webExtension;
+let waitForWebExtensionAPI;
+
+module.exports = {
+  initFromBootstrapAddonParam(data) {
+    if (webExtension) {
+      throw new Error("'sdk/webextension' module has been already initialized");
+    }
+
+    webExtension = data.webExtension;
+  },
+
+  startup() {
+    if (!webExtension) {
+      return Promise.reject(new Error(
+        "'sdk/webextension' module is currently disabled. " +
+        "('hasEmbeddedWebExtension' option is missing or set to false)"
+      ));
+    }
+
+    // NOTE: calling `startup` more than once raises an "Embedded Extension already started"
+    // error, but given that SDK addons are going to have access to the startup method through
+    // an SDK module that can be required in any part of the addon, it will be nicer if any
+    // additional startup calls return the startup promise instead of raising an exception,
+    // so that the SDK addon can access the API object in the other addon modules without the
+    // need to manually pass this promise around.
+    if (!waitForWebExtensionAPI) {
+      waitForWebExtensionAPI = webExtension.startup();
+    }
+
+    return waitForWebExtensionAPI;
+  }
+};