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/json-stable-stringify-without-jsonify/test/str.js

@@ -0,0 +1,32 @@
+var test = require('tape');
+var stringify = require('../');
+
+test('simple object', function (t) {
+    t.plan(1);
+    var obj = { c: 6, b: [4,5], a: 3, z: null };
+    t.equal(stringify(obj), '{"a":3,"b":[4,5],"c":6,"z":null}');
+});
+
+test('object with undefined', function (t) {
+	t.plan(1);
+	var obj = { a: 3, z: undefined };
+	t.equal(stringify(obj), '{"a":3}');
+});
+
+test('array with undefined', function (t) {
+	t.plan(1);
+	var obj = [4, undefined, 6];
+	t.equal(stringify(obj), '[4,null,6]');
+});
+
+test('object with empty string', function (t) {
+	t.plan(1);
+	var obj = { a: 3, z: '' };
+	t.equal(stringify(obj), '{"a":3,"z":""}');
+});
+
+test('array with empty string', function (t) {
+	t.plan(1);
+	var obj = [4, '', 6];
+	t.equal(stringify(obj), '[4,"",6]');
+});