CLI Implementation with Click (#2107)

* Initial CLI implementation with click package

* Adding fetch command for pulling examples and deepspeed configs

* Automating default options for CliArgs classes

* Mimicking existing no config behavior

* bugfix in choose_config

* Updating fetch to sync instead of re-download

* bugfix

* isort fix

* fixing yaml isort order

* pre-commit fixes

* simplifying argument parsing -- pass through kwargs to do_cli

* make accelerate launch default for non-preprocess commands

* fixing arg handling

* testing None placeholder approach

* removing hacky --use-gpu argument to preprocess command

* Adding brief README documentation for CLI

* remove (New)

* Initial CLI pytest tests

* progress on CLI pytest

* adding inference CLI tests; cleanup

* Refactor train CLI tests to remove various mocking

* Major CLI test refator; adding remaining CLI codepath test coverage

* pytest fixes

* remove integration markers

* parallelizing examples, deepspeed config downloads; rename test to match other CLI test naming

* moving cli pytest due to isolation issues; cleanup

* testing fixes; various minor improvements

* fix

* tests fix

* Update tests/cli/conftest.py

Co-authored-by: Wing Lian <wing.lian@gmail.com>

---------

Co-authored-by: Dan Saunders <dan@axolotl.ai>
Co-authored-by: Wing Lian <wing.lian@gmail.com>

tests/cli/test_utils.py

@@ -0,0 +1,89 @@
+"""pytest tests for axolotl CLI utils."""
+# pylint: disable=redefined-outer-name
+import json
+from unittest.mock import Mock, patch
+
+import click
+import pytest
+import requests
+
+from axolotl.cli.utils import fetch_from_github
+
+# Sample GitHub API response
+MOCK_TREE_RESPONSE = {
+    "tree": [
+        {"path": "examples/config1.yml", "type": "blob", "sha": "abc123"},
+        {"path": "examples/config2.yml", "type": "blob", "sha": "def456"},
+        {"path": "other/file.txt", "type": "blob", "sha": "xyz789"},
+    ]
+}
+
+
+@pytest.fixture
+def mock_responses():
+    """Mock responses for API and file downloads"""
+
+    def mock_get(url, timeout=None):  # pylint: disable=unused-argument
+        response = Mock()
+        if "api.github.com" in url:
+            response.text = json.dumps(MOCK_TREE_RESPONSE)
+        else:
+            response.content = b"file content"
+        return response
+
+    return mock_get
+
+
+def test_fetch_from_github_new_files(tmp_path, mock_responses):
+    """Test fetching new files"""
+    with patch("requests.get", mock_responses):
+        fetch_from_github("examples/", tmp_path)
+
+        # Verify files were created
+        assert (tmp_path / "config1.yml").exists()
+        assert (tmp_path / "config2.yml").exists()
+        assert not (tmp_path / "file.txt").exists()
+
+
+def test_fetch_from_github_unchanged_files(tmp_path, mock_responses):
+    """Test handling of unchanged files"""
+    # Create existing file with matching SHA
+    existing_file = tmp_path / "config1.yml"
+    existing_file.write_bytes(b"file content")
+
+    with patch("requests.get", mock_responses):
+        fetch_from_github("examples/", tmp_path)
+
+        # File should not be downloaded again
+        assert existing_file.read_bytes() == b"file content"
+
+
+def test_fetch_from_github_invalid_prefix(mock_responses):
+    """Test error handling for invalid directory prefix"""
+    with patch("requests.get", mock_responses):
+        with pytest.raises(click.ClickException):
+            fetch_from_github("nonexistent/", None)
+
+
+def test_fetch_from_github_network_error():
+    """Test handling of network errors"""
+    with patch("requests.get", side_effect=requests.RequestException):
+        with pytest.raises(requests.RequestException):
+            fetch_from_github("examples/", None)
+
+
+@pytest.fixture
+def integration_test_dir(tmp_path):
+    """Fixture for integration test directory that cleans up after itself"""
+    test_dir = tmp_path / "github_downloads"
+    test_dir.mkdir(parents=True)
+    yield test_dir
+
+
+def test_fetch_from_github_real(integration_test_dir):
+    """Test actual GitHub API interaction"""
+    fetch_from_github("examples/", integration_test_dir)
+
+    # Verify some known files exist
+    assert (integration_test_dir / "openllama-3b" / "lora.yml").exists()
+    assert (integration_test_dir / "openllama-3b" / "qlora.yml").exists()