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_cli_fetch.py

@@ -0,0 +1,38 @@
+"""pytest tests for axolotl CLI fetch command."""
+from unittest.mock import patch
+
+from axolotl.cli.main import fetch
+
+
+def test_fetch_cli_examples(cli_runner):
+    """Test fetch command with examples directory"""
+    with patch("axolotl.cli.main.fetch_from_github") as mock_fetch:
+        result = cli_runner.invoke(fetch, ["examples"])
+
+        assert result.exit_code == 0
+        mock_fetch.assert_called_once_with("examples/", None)
+
+
+def test_fetch_cli_deepspeed(cli_runner):
+    """Test fetch command with deepspeed_configs directory"""
+    with patch("axolotl.cli.main.fetch_from_github") as mock_fetch:
+        result = cli_runner.invoke(fetch, ["deepspeed_configs"])
+
+        assert result.exit_code == 0
+        mock_fetch.assert_called_once_with("deepspeed_configs/", None)
+
+
+def test_fetch_cli_with_dest(cli_runner, tmp_path):
+    """Test fetch command with custom destination"""
+    with patch("axolotl.cli.main.fetch_from_github") as mock_fetch:
+        custom_dir = tmp_path / "tmp_examples"
+        result = cli_runner.invoke(fetch, ["examples", "--dest", str(custom_dir)])
+
+        assert result.exit_code == 0
+        mock_fetch.assert_called_once_with("examples/", str(custom_dir))
+
+
+def test_fetch_cli_invalid_directory(cli_runner):
+    """Test fetch command with invalid directory choice"""
+    result = cli_runner.invoke(fetch, ["invalid"])
+    assert result.exit_code != 0