[http] add unix socket test

Open random unix socket and try communication with curl.
Require minimum curl 7.50

Author: linev

net/http/test/CMakeLists.txt

@@ -34,7 +34,10 @@ execute_process(
 # curl introduce support from 8.11 but it works reliably only with 8.18
 if(CURL_CLI_OUTPUT MATCHES "curl ([0-9]+\\.[0-9]+\\.[0-9]+)")
   set(CURL_CLI_VERSION "${CMAKE_MATCH_1}")
-  message(STATUS "Find curl ${CURL_CLI_VERSION} for http server tests")
+  message(STATUS "Found curl ${CURL_CLI_VERSION} for http server tests")
+  if(CURL_CLI_VERSION VERSION_GREATER_EQUAL "7.50.0")
+    ROOT_ADD_GTEST(testUnixSocket test_xsocket.cxx LIBRARIES RHTTP RHTTPSniff Hist)
+  endif()
   if(CURL_CLI_VERSION VERSION_GREATER_EQUAL "8.18.0")
     ROOT_ADD_GTEST(testWebSocket test_websocket.cxx LIBRARIES RHTTP Hist)
   endif()

net/http/test/test_xsocket.cxx

@@ -0,0 +1,52 @@
+#include "gtest/gtest.h"
+
+#include <string>
+#include <fstream>
+
+#include "THttpServer.h"
+#include "TROOT.h"
+
+#include "TSystem.h"
+#include "TNamed.h"
+#include "TRandom.h"
+
+#include "ROOT/TestSupport.hxx"
+
+
+#include "./test_suite.cxx"
+
+// main http server
+TEST(THttpServer, main)
+{
+   THttpServer serv("");
+
+   TString fname;
+   Bool_t create = kFALSE;
+
+   for (Int_t ntry = 0; ntry < 10; ++ntry) {
+      fname = "root_test_";
+      auto f = gSystem->TempFileName(fname, nullptr, ".socket");
+      if (!f)
+         continue;
+      fclose(f);
+
+      EXPECT_EQ(fname[0], '/') << "first symbol in temporary file must be slash";
+      create = serv.CreateEngine("socket:" + fname + "?socket_mode=0700");
+
+      if (create)
+         break;
+
+      gSystem->Unlink(fname);
+   }
+
+   EXPECT_EQ(create, kTRUE) << "create unix socket";
+
+   if (!create)
+      return;
+
+   server_hash = fname.Hash();  // dummy number for file suffix
+   unix_socket = "--unix-socket " + fname; // curl argument
+   server_url = "http://localhost"; // dummy host name for curl
+
+   test_suite(serv);
+}