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-routing/src/utils/constants.ts

@@ -0,0 +1,37 @@
+/*
+  Copyright 2018 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';
+
+export type HTTPMethod = 'DELETE' | 'GET' | 'HEAD' | 'PATCH' | 'POST' | 'PUT';
+
+/**
+ * The default HTTP method, 'GET', used when there's no specific method
+ * configured for a route.
+ *
+ * @type {string}
+ *
+ * @private
+ */
+export const defaultMethod: HTTPMethod = 'GET';
+
+/**
+ * The list of valid HTTP methods associated with requests that could be routed.
+ *
+ * @type {Array<string>}
+ *
+ * @private
+ */
+export const validMethods: HTTPMethod[] = [
+  'DELETE',
+  'GET',
+  'HEAD',
+  'PATCH',
+  'POST',
+  'PUT',
+];

node_modules/workbox-routing/src/utils/getOrCreateDefaultRouter.ts

@@ -0,0 +1,30 @@
+/*
+  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 {Router} from '../Router.js';
+import '../_version.js';
+
+let defaultRouter: Router;
+
+/**
+ * Creates a new, singleton Router instance if one does not exist. If one
+ * does already exist, that instance is returned.
+ *
+ * @private
+ * @return {Router}
+ */
+export const getOrCreateDefaultRouter = (): Router => {
+  if (!defaultRouter) {
+    defaultRouter = new Router();
+
+    // The helpers that use the default Router assume these listeners exist.
+    defaultRouter.addFetchListener();
+    defaultRouter.addCacheListener();
+  }
+  return defaultRouter;
+};

node_modules/workbox-routing/src/utils/normalizeHandler.ts

@@ -0,0 +1,43 @@
+/*
+  Copyright 2018 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 {assert} from 'workbox-core/_private/assert.js';
+import {RouteHandler, RouteHandlerObject} from 'workbox-core/types.js';
+
+import '../_version.js';
+
+/**
+ * @param {function()|Object} handler Either a function, or an object with a
+ * 'handle' method.
+ * @return {Object} An object with a handle method.
+ *
+ * @private
+ */
+export const normalizeHandler = (handler: RouteHandler): RouteHandlerObject => {
+  if (handler && typeof handler === 'object') {
+    if (process.env.NODE_ENV !== 'production') {
+      assert!.hasMethod(handler, 'handle', {
+        moduleName: 'workbox-routing',
+        className: 'Route',
+        funcName: 'constructor',
+        paramName: 'handler',
+      });
+    }
+    return handler;
+  } else {
+    if (process.env.NODE_ENV !== 'production') {
+      assert!.isType(handler, 'function', {
+        moduleName: 'workbox-routing',
+        className: 'Route',
+        funcName: 'constructor',
+        paramName: 'handler',
+      });
+    }
+    return {handle: handler};
+  }
+};