// Tests that domains longer than 253 characters fail to load when pref is true add_task(async function test_long_domain_fails() { let domain = "http://" + "a".repeat(254); let req = await new Promise(resolve => { let chan = NetUtil.newChannel({ uri: domain, loadUsingSystemPrincipal: true, }); chan.asyncOpen(new ChannelListener(resolve, null, CL_EXPECT_FAILURE)); }); Assert.equal(req.status, Cr.NS_ERROR_UNKNOWN_HOST, "Request should fail"); });