WIP - add extractor, generate snippet_data

node_modules/workbox-streams/isSupported.mjs

@@ -0,0 +1,45 @@
+/*
+ Copyright 2018 Google Inc. All Rights Reserved.
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+import './_version.mjs';
+
+let cachedIsSupported = undefined;
+
+/**
+ * This is a utility method that determines whether the current browser supports
+ * the features required to create streamed responses. Currently, it checks if
+ * [`ReadableStream`](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream/ReadableStream)
+ * can be created.
+ *
+ * @return {boolean} `true`, if the current browser meets the requirements for
+ * streaming responses, and `false` otherwise.
+ *
+ * @memberof workbox.streams
+ */
+function isSupported() {
+  if (cachedIsSupported === undefined) {
+    // See https://github.com/GoogleChrome/workbox/issues/1473
+    try {
+      new ReadableStream({start() {}});
+      cachedIsSupported = true;
+    } catch (error) {
+      cachedIsSupported = false;
+    }
+  }
+
+  return cachedIsSupported;
+}
+
+export {isSupported};