Tests: more Node.js tests.

test/node/has_header/app.js

@@ -0,0 +1,6 @@
+#!/usr/bin/env node
+
+require('unit-http').createServer(function (req, res) {
+    res.setHeader('X-Has-Header', res.hasHeader(req['headers']['X-Header']) + '');
+    res.end();
+}).listen(7080);