Initial commit: Developer Tools MVP with visual editor

- Complete React app with 7 developer tools
- JSON Tool with visual structured editor
- Serialize Tool with visual structured editor
- URL, Base64, CSV/JSON, Beautifier, Diff tools
- Responsive navigation with dropdown menu
- Dark/light mode toggle
- Mobile-responsive design with sticky header
- All tools working with copy/paste functionality

node_modules/workbox-window/messageSW.js

@@ -0,0 +1,34 @@
+/*
+  Copyright 2019 Google LLC
+
+  Use of this source code is governed by an MIT-style
+  license that can be found in the LICENSE file or at
+  https://opensource.org/licenses/MIT.
+*/
+import './_version.js';
+/**
+ * Sends a data object to a service worker via `postMessage` and resolves with
+ * a response (if any).
+ *
+ * A response can be set in a message handler in the service worker by
+ * calling `event.ports[0].postMessage(...)`, which will resolve the promise
+ * returned by `messageSW()`. If no response is set, the promise will not
+ * resolve.
+ *
+ * @param {ServiceWorker} sw The service worker to send the message to.
+ * @param {Object} data An object to send to the service worker.
+ * @return {Promise<Object|undefined>}
+ * @memberof workbox-window
+ */
+// Better not change type of data.
+// eslint-disable-next-line @typescript-eslint/ban-types
+function messageSW(sw, data) {
+    return new Promise((resolve) => {
+        const messageChannel = new MessageChannel();
+        messageChannel.port1.onmessage = (event) => {
+            resolve(event.data);
+        };
+        sw.postMessage(data, [messageChannel.port2]);
+    });
+}
+export { messageSW };