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/@testing-library/user-event/dist/clear.js

@@ -0,0 +1,48 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.clear = clear;
+
+var _utils = require("./utils");
+
+var _type = require("./type");
+
+function clear(element) {
+  var _element$selectionSta, _element$selectionEnd;
+
+  if (!(0, _utils.isElementType)(element, ['input', 'textarea'])) {
+    // TODO: support contenteditable
+    throw new Error('clear currently only supports input and textarea elements.');
+  }
+
+  if ((0, _utils.isDisabled)(element)) {
+    return;
+  } // TODO: track the selection range ourselves so we don't have to do this input "type" trickery
+  // just like cypress does: https://github.com/cypress-io/cypress/blob/8d7f1a0bedc3c45a2ebf1ff50324b34129fdc683/packages/driver/src/dom/selection.ts#L16-L37
+
+
+  const elementType = element.type;
+
+  if (elementType !== 'textarea') {
+    // setSelectionRange is not supported on certain types of inputs, e.g. "number" or "email"
+    ;
+    element.type = 'text';
+  }
+
+  (0, _type.type)(element, '{selectall}{del}', {
+    delay: 0,
+    initialSelectionStart: (_element$selectionSta = element.selectionStart) != null ? _element$selectionSta :
+    /* istanbul ignore next */
+    undefined,
+    initialSelectionEnd: (_element$selectionEnd = element.selectionEnd) != null ? _element$selectionEnd :
+    /* istanbul ignore next */
+    undefined
+  });
+
+  if (elementType !== 'textarea') {
+    ;
+    element.type = elementType;
+  }
+}