From 630e09bf949aca33ba02a18e19b8d17431fb8bbe Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 4 Mar 2026 08:08:22 +0000
Subject: [PATCH] test: add unit tests for the CLI commands

Adds comprehensive unit tests for `neuroscope/cli.py` to ensure proper argument parsing, command routing, and correct behavior of `main()`, `run_server()`, `run_demo()`, and `show_version()`. Mocking is used heavily to verify behavior deterministically without the need to bind network ports, load slow machine learning framework binaries, or start infinite sleep loops.

Co-authored-by: harshithluc073 <101515387+harshithluc073@users.noreply.github.com>
---
 patch.diff        |  32 ++++++++
 tests/test_cli.py | 195 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 227 insertions(+)
 create mode 100644 patch.diff
 create mode 100644 tests/test_cli.py

diff --git a/patch.diff b/patch.diff
new file mode 100644
index 0000000..bc406e8
--- /dev/null
+++ b/patch.diff
@@ -0,0 +1,32 @@
+<<<<<<< SEARCH
+@patch("builtins.__import__", side_effect=ImportError)
+def test_run_demo_no_torch(mock_import, capsys):
+    """Test running the demo when torch is not installed."""
+    # We only want to mock torch import, let others pass
+    original_import = __import__
+    def side_effect(name, *args, **kwargs):
+        if name == "torch":
+            raise ImportError("No module named 'torch'")
+        return original_import(name, *args, **kwargs)
+
+    mock_import.side_effect = side_effect
+
+    args = MagicMock()
+    args.model = "mlp"
+
+    assert run_demo(args) == 1
+
+    out, err = capsys.readouterr()
+    assert "[ERROR] PyTorch is required for demo" in out
+=======
+def test_run_demo_no_torch(capsys):
+    """Test running the demo when torch is not installed."""
+    args = MagicMock()
+    args.model = "mlp"
+
+    with patch.dict("sys.modules", {"torch": None}):
+        assert run_demo(args) == 1
+
+    out, err = capsys.readouterr()
+    assert "[ERROR] PyTorch is required for demo" in out
+>>>>>>> REPLACE
diff --git a/tests/test_cli.py b/tests/test_cli.py
new file mode 100644
index 0000000..b4eafdc
--- /dev/null
+++ b/tests/test_cli.py
@@ -0,0 +1,195 @@
+"""Tests for the command-line interface."""
+
+import sys
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from neuroscope.cli import main, run_demo, run_server, show_version
+
+
+@pytest.fixture
+def mock_argv(monkeypatch):
+    """Fixture to easily mock sys.argv."""
+    def _mock(*args):
+        monkeypatch.setattr(sys, "argv", ["neuroscope", *args])
+    return _mock
+
+
+def test_main_no_args(mock_argv, capsys):
+    """Test that main with no args prints help and returns 0."""
+    mock_argv()
+
+    # We need to mock parser.print_help since argparse's default behavior
+    # might differ slightly, but we can just let it print and capture it.
+    with patch("argparse.ArgumentParser.print_help") as mock_print_help:
+        assert main() == 0
+        mock_print_help.assert_called_once()
+
+
+@patch("neuroscope.cli.run_server")
+def test_main_server_command(mock_run_server, mock_argv):
+    """Test routing to server command."""
+    mock_run_server.return_value = 0
+    mock_argv("server", "--port", "9000", "--host", "0.0.0.0", "--no-browser")
+
+    assert main() == 0
+
+    mock_run_server.assert_called_once()
+    args = mock_run_server.call_args[0][0]
+    assert args.port == 9000
+    assert args.host == "0.0.0.0"
+    assert args.no_browser is True
+
+
+@patch("neuroscope.cli.run_demo")
+def test_main_demo_command(mock_run_demo, mock_argv):
+    """Test routing to demo command."""
+    mock_run_demo.return_value = 0
+    mock_argv("demo", "--model", "cnn")
+
+    assert main() == 0
+
+    mock_run_demo.assert_called_once()
+    args = mock_run_demo.call_args[0][0]
+    assert args.model == "cnn"
+
+
+@patch("neuroscope.cli.show_version")
+def test_main_version_command(mock_show_version, mock_argv):
+    """Test routing to version command."""
+    mock_show_version.return_value = 0
+    mock_argv("version")
+
+    assert main() == 0
+    mock_show_version.assert_called_once()
+
+
+@patch("neuroscope.core.server.NeuroScopeServer")
+@patch("time.sleep", side_effect=KeyboardInterrupt)
+def test_run_server_normal(mock_sleep, mock_server_cls, capsys):
+    """Test running the server with normal shutdown."""
+    # Setup mock server
+    mock_server = MagicMock()
+    mock_server_cls.return_value = mock_server
+
+    # Setup args
+    args = MagicMock()
+    args.host = "localhost"
+    args.port = 8765
+    args.no_browser = False
+
+    assert run_server(args) == 0
+
+    mock_server_cls.assert_called_once_with(host="localhost", port=8765)
+    mock_server.start.assert_called_once_with(open_browser=True)
+    mock_server.stop.assert_called_once()
+
+    out, err = capsys.readouterr()
+    assert "Starting server..." in out
+    assert "Shutting down..." in out
+
+
+def test_show_version(capsys):
+    """Test the version display."""
+    from neuroscope import __version__
+    assert show_version() == 0
+    out, err = capsys.readouterr()
+    assert f"NeuroScope {__version__}" in out
+
+
+@patch("neuroscope.cli.run_server")
+def test_main_server_default_args(mock_run_server, mock_argv):
+    """Test routing to server command with default arguments."""
+    mock_run_server.return_value = 0
+    mock_argv("server")
+
+    assert main() == 0
+
+    mock_run_server.assert_called_once()
+    args = mock_run_server.call_args[0][0]
+    assert args.port == 8765
+    assert args.host == "localhost"
+    assert args.no_browser is False
+
+
+@patch("neuroscope.cli.run_demo")
+def test_main_demo_default_args(mock_run_demo, mock_argv):
+    """Test routing to demo command with default arguments."""
+    mock_run_demo.return_value = 0
+    mock_argv("demo")
+
+    assert main() == 0
+
+    mock_run_demo.assert_called_once()
+    args = mock_run_demo.call_args[0][0]
+    assert args.model == "mlp"
+
+
+@patch("neuroscope.attach")
+@patch("neuroscope.start_server")
+@patch("neuroscope.detach")
+@patch("neuroscope.stop_server")
+@patch("time.sleep", side_effect=KeyboardInterrupt)
+def test_run_demo_mlp(mock_sleep, mock_stop, mock_detach, mock_start, mock_attach, capsys):
+    """Test running the demo with mlp model."""
+    args = MagicMock()
+    args.model = "mlp"
+
+    assert run_demo(args) == 0
+
+    mock_attach.assert_called_once()
+    mock_start.assert_called_once()
+    mock_detach.assert_called_once()
+    mock_stop.assert_called_once()
+
+    out, err = capsys.readouterr()
+    assert "Creating mlp model..." in out
+    assert "Attaching tracer..." in out
+    assert "Running forward pass..." in out
+
+
+@patch("neuroscope.attach")
+@patch("neuroscope.start_server")
+@patch("neuroscope.detach")
+@patch("neuroscope.stop_server")
+@patch("time.sleep", side_effect=KeyboardInterrupt)
+def test_run_demo_cnn(mock_sleep, mock_stop, mock_detach, mock_start, mock_attach, capsys):
+    """Test running the demo with cnn model."""
+    args = MagicMock()
+    args.model = "cnn"
+
+    assert run_demo(args) == 0
+
+    mock_attach.assert_called_once()
+    out, err = capsys.readouterr()
+    assert "Creating cnn model..." in out
+
+
+@patch("neuroscope.attach")
+@patch("neuroscope.start_server")
+@patch("neuroscope.detach")
+@patch("neuroscope.stop_server")
+@patch("time.sleep", side_effect=KeyboardInterrupt)
+def test_run_demo_transformer(mock_sleep, mock_stop, mock_detach, mock_start, mock_attach, capsys):
+    """Test running the demo with transformer model."""
+    args = MagicMock()
+    args.model = "transformer"
+
+    assert run_demo(args) == 0
+
+    mock_attach.assert_called_once()
+    out, err = capsys.readouterr()
+    assert "Creating transformer model..." in out
+
+
+def test_run_demo_no_torch(capsys):
+    """Test running the demo when torch is not installed."""
+    args = MagicMock()
+    args.model = "mlp"
+
+    with patch.dict("sys.modules", {"torch": None}):
+        assert run_demo(args) == 1
+
+    out, err = capsys.readouterr()
+    assert "[ERROR] PyTorch is required for demo" in out