Bug 1580976 - Check that moz-http2.js is working before running test_trr.js r=JuniorHsu

Differential Revision: https://phabricator.services.mozilla.com/D49309

--HG--
extra : moz-landing-system : lando

netwerk/test/unit/test_trr.js

@@ -1,5 +1,6 @@
 "use strict";
 
+const { NodeServer } = ChromeUtils.import("resource://testing-common/httpd.js");
 const dns = Cc["@mozilla.org/network/dns-service;1"].getService(
   Ci.nsIDNSService
 );
@@ -140,6 +141,17 @@ class DNSListener {
   }
 }
 
+add_task(async function test0_nodeExecute() {
+  // This test checks that moz-http2.js running in node is working.
+  // This should always be the first test in this file (except for setup)
+  // otherwise we may encounter random failures when the http2 server is down.
+  equal(
+    await NodeServer.execute(`"hello"`),
+    "hello",
+    "Check that moz-http2.js is running"
+  );
+});
+
 // verify basic A record
 add_task(async function test1() {
   dns.clearCache(true);