test: add http.ClientRequest defaults test

PR-URL: nodejs#10654
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>

test/parallel/test-http-client-defaults.js

@@ -0,0 +1,24 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+const ClientRequest = require('http').ClientRequest;
+
+function noop() {}
+
+{
+  const req = new ClientRequest({ createConnection: noop });
+  assert.strictEqual(req.path, '/');
+  assert.strictEqual(req.method, 'GET');
+}
+
+{
+  const req = new ClientRequest({ method: '', createConnection: noop });
+  assert.strictEqual(req.path, '/');
+  assert.strictEqual(req.method, 'GET');
+}
+
+{
+  const req = new ClientRequest({ path: '', createConnection: noop });
+  assert.strictEqual(req.path, '/');
+  assert.strictEqual(req.method, 'GET');
+}