Hide Windows console when launching pg0

Merges the Windows console suppression fix for issue #32.

Author: nicoloboschi

sdk/python/pg0/__init__.py

@@ -143,6 +143,9 @@ def _run_pg0(*args: str, check: bool = True) -> subprocess.CompletedProcess:
                     [pg0_path, *args],
                     stdout=out_f,
                     stderr=err_f,
+                    # pg0 is a console executable. Suppress the transient console
+                    # window when it is launched from a GUI Python application.
+                    creationflags=subprocess.CREATE_NO_WINDOW,
                 )
                 out_f.seek(0)
                 err_f.seek(0)

sdk/python/tests/test_pg0.py

@@ -6,6 +6,7 @@
 import sys
 import tempfile
 import time
+from unittest.mock import patch
 
 import pytest
 import pg0
@@ -32,6 +33,19 @@ def clean_instance():
 class TestPg0:
     """Tests for Pg0 class."""
 
+    @pytest.mark.skipif(sys.platform != "win32", reason="Windows-specific subprocess flags")
+    def test_windows_runner_hides_console_window(self):
+        """The Python wrapper must not create a console window for pg0.exe.
+
+        Regression test for https://github.com/vectorize-io/pg0/issues/32.
+        """
+        with patch.object(pg0, "_find_pg0", return_value="pg0.exe"), patch.object(
+            pg0.subprocess, "call", return_value=0
+        ) as call:
+            pg0._run_pg0("start")
+
+        assert call.call_args.kwargs["creationflags"] == subprocess.CREATE_NO_WINDOW
+
     def test_start_stop(self, clean_instance):
         """Test starting and stopping Pg0."""
         pg = Pg0(name=TEST_NAME, port=TEST_PORT)