Fix #305: Add "pythonArgs" config property for interpreter arguments

Expose "pythonArgs" to clients.

Make "python" usable in tests in lieu of "pythonPath", and make the runners use it.

Add tests for all combinations of "python"/"pythonPath" and "pythonArgs".

src/debugpy/adapter/clients.py

@@ -302,6 +302,8 @@ def property_or_debug_option(prop_name, flag_name):
         python = request(python_key, json.array(unicode, vectorize=True, size=(0,)))
         if not len(python):
             python = [compat.filename(sys.executable)]
+
+        python += request("pythonArgs", json.array(unicode, size=(0,)))
         request.arguments["pythonArgs"] = python[1:]
 
         program = module = code = ()

tests/debug/config.py

@@ -42,6 +42,8 @@ class DebugConfig(collections.MutableMapping):
         "postDebugTask": (),
         "preLaunchTask": (),
         "pyramid": False,
+        "python": (),
+        "pythonArgs": [],
         "pythonPath": (),
         "redirectOutput": False,
         "rules": [],

tests/debug/runners.py

@@ -117,23 +117,22 @@ def pytest_id(self):
 
 
 @_runner
-def launch(session, target, console="integratedTerminal", cwd=None):
-    assert console in ("internalConsole", "integratedTerminal", "externalTerminal")
+def launch(session, target, console=None, cwd=None):
+    assert console in (None, "internalConsole", "integratedTerminal", "externalTerminal")
 
     log.info("Launching {0} in {1} using {2!j}.", target, session, console)
 
     target.configure(session)
     config = session.config
     config.setdefaults(
-        {
-            "console": "externalTerminal",
-            "internalConsoleOptions": "neverOpen",
-            "pythonPath": sys.executable,
-        }
+        {"console": "externalTerminal", "internalConsoleOptions": "neverOpen"}
     )
-    config["console"] = console
+    if console is not None:
+        config["console"] = console
     if cwd is not None:
         config["cwd"] = cwd
+    if "python" not in config and "pythonPath" not in config:
+        config["python"] = sys.executable
 
     env = (
         session.spawn_adapter.env

tests/debugpy/test_run.py

@@ -138,27 +138,43 @@ def code_to_debug():
 
 
 @pytest.mark.parametrize("run", runners.all_launch_terminal)
-def test_custom_python(pyfile, run, target):
+@pytest.mark.parametrize("python_args", ["", "-v"])
+@pytest.mark.parametrize("python", ["", "custompy", "custompy -O"])
+@pytest.mark.parametrize("python_key", ["python", "pythonPath"])
+def test_custom_python(pyfile, run, target, python_key, python, python_args):
     @pyfile
     def code_to_debug():
         import sys
         import debuggee
         from debuggee import backchannel
 
         debuggee.setup()
-        backchannel.send(sys.executable)
+        backchannel.send([sys.executable, sys.flags.optimize, sys.flags.verbose])
+
+    python = python.split()
+    python_args = python_args.split()
+    python_cmd = (python if len(python) else [sys.executable]) + python_args
 
     class Session(debug.Session):
         def run_in_terminal(self, args, cwd, env):
-            assert args[:2] == ["CUSTOMPY", "-O"]
+            assert args[: len(python_cmd)] == python_cmd
             args[0] = sys.executable
             return super(Session, self).run_in_terminal(args, cwd, env)
 
     with Session() as session:
-        session.config["pythonPath"] = ["CUSTOMPY", "-O"]
+        session.config.pop("python", None)
+        session.config.pop("pythonPath", None)
+        if len(python):
+            session.config[python_key] = python[0] if len(python) == 1 else python
+        if len(python_args):
+            session.config["pythonArgs"] = python_args
 
         backchannel = session.open_backchannel()
         with run(session, target(code_to_debug)):
             pass
 
-        assert backchannel.receive() == sys.executable
+        assert backchannel.receive() == [
+            sys.executable,
+            "-O" in python_cmd,
+            "-v" in python_cmd,
+        ]