Roughing out the demo app

node_modules/semver-diff/index.js

@@ -0,0 +1,27 @@
+'use strict';
+var semver = require('semver');
+
+module.exports = function (a, b) {
+	if (semver.gt(a, b)) {
+		return null;
+	}
+
+	a = semver.parse(a);
+	b = semver.parse(b);
+
+	for (var key in a) {
+		if (key === 'major' || key === 'minor' || key === 'patch') {
+			if (a[key] !== b[key]) {
+				return key;
+			}
+		}
+
+		if (key === 'prerelease' || key === 'build') {
+			if (JSON.stringify(a[key]) !== JSON.stringify(b[key])) {
+				return key;
+			}
+		}
+	}
+
+	return null;
+};