cli[minor]: Add langgraph new command (#2369)

Adds a "new" command to create langgraph application from a template.

libs/cli/tests/unit_tests/cli/test_templates.py

@@ -0,0 +1,70 @@
+"""Unit tests for the 'new' CLI command.
+
+This command creates a new LangGraph project using a specified template.
+"""
+
+import os
+from io import BytesIO
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from unittest.mock import MagicMock, patch
+from urllib import request
+from zipfile import ZipFile
+
+from click.testing import CliRunner
+
+from langgraph_cli.cli import cli
+from langgraph_cli.templates import TEMPLATE_ID_TO_CONFIG
+
+
+@patch.object(request, "urlopen")
+def test_create_new_with_mocked_download(mock_urlopen: MagicMock) -> None:
+    """Test the 'new' CLI command with a mocked download response using urllib."""
+    # Mock the response content to simulate a ZIP file
+    mock_zip_content = BytesIO()
+    with ZipFile(mock_zip_content, "w") as mock_zip:
+        mock_zip.writestr("test-file.txt", "Test content.")
+
+    # Create a mock response that behaves like a context manager
+    mock_response = MagicMock()
+    mock_response.read.return_value = mock_zip_content.getvalue()
+    mock_response.__enter__.return_value = mock_response  # Setup enter context
+    mock_response.status = 200
+
+    mock_urlopen.return_value = mock_response
+
+    with TemporaryDirectory() as temp_dir:
+        runner = CliRunner()
+        template = next(
+            iter(TEMPLATE_ID_TO_CONFIG)
+        )  # Select the first template for the test
+        result = runner.invoke(cli, ["new", temp_dir, "--template", template])
+
+        # Verify CLI command execution and success
+        assert result.exit_code == 0, result.output
+        assert (
+            "New project created" in result.output
+        ), "Expected success message in output."
+
+        # Verify that the directory is not empty
+        assert os.listdir(temp_dir), "Expected files to be created in temp directory."
+
+        # Check for a known file in the extracted content
+        extracted_files = [f.name for f in Path(temp_dir).glob("*")]
+        assert (
+            "test-file.txt" in extracted_files
+        ), "Expected 'test-file.txt' in the extracted content."
+
+
+def test_invalid_template_id() -> None:
+    """Test that an invalid template ID passed via CLI results in a graceful error."""
+    runner = CliRunner()
+    result = runner.invoke(
+        cli, ["new", "dummy_path", "--template", "invalid-template-id"]
+    )
+
+    # Verify the command failed and proper message is displayed
+    assert result.exit_code != 0, "Expected non-zero exit code for invalid template."
+    assert (
+        "Template 'invalid-template-id' not found" in result.output
+    ), "Expected error message in output."

libs/cli/tests/unit_tests/conftest.py

@@ -0,0 +1,16 @@
+import os
+from unittest.mock import patch
+
+import pytest
+
+
+@pytest.fixture(autouse=True)
+def disable_analytics_env() -> None:
+    """Disable analytics for unit tests LANGGRAPH_CLI_NO_ANALYTICS."""
+    # First check if the environment variable is already set, if so, log a warning prior
+    # to overriding it.
+    if "LANGGRAPH_CLI_NO_ANALYTICS" in os.environ:
+        print("⚠️ LANGGRAPH_CLI_NO_ANALYTICS is set. Overriding it for the test.")
+
+    with patch.dict(os.environ, {"LANGGRAPH_CLI_NO_ANALYTICS": "0"}):
+        yield