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/compressible/index.js

@@ -0,0 +1,58 @@
+/*!
+ * compressible
+ * Copyright(c) 2013 Jonathan Ong
+ * Copyright(c) 2014 Jeremiah Senkpiel
+ * Copyright(c) 2015 Douglas Christopher Wilson
+ * MIT Licensed
+ */
+
+'use strict'
+
+/**
+ * Module dependencies.
+ * @private
+ */
+
+var db = require('mime-db')
+
+/**
+ * Module variables.
+ * @private
+ */
+
+var COMPRESSIBLE_TYPE_REGEXP = /^text\/|\+(?:json|text|xml)$/i
+var EXTRACT_TYPE_REGEXP = /^\s*([^;\s]*)(?:;|\s|$)/
+
+/**
+ * Module exports.
+ * @public
+ */
+
+module.exports = compressible
+
+/**
+ * Checks if a type is compressible.
+ *
+ * @param {string} type
+ * @return {Boolean} compressible
+ * @public
+ */
+
+function compressible (type) {
+  if (!type || typeof type !== 'string') {
+    return false
+  }
+
+  // strip parameters
+  var match = EXTRACT_TYPE_REGEXP.exec(type)
+  var mime = match && match[1].toLowerCase()
+  var data = db[mime]
+
+  // return database information
+  if (data && data.compressible !== undefined) {
+    return data.compressible
+  }
+
+  // fallback to regexp or unknown
+  return COMPRESSIBLE_TYPE_REGEXP.test(mime) || undefined
+}