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/conftest.py

@@ -0,0 +1,36 @@
+"""Shared pytest fixtures for cli module."""
+import pytest
+from click.testing import CliRunner
+
+VALID_TEST_CONFIG = """
+base_model: HuggingFaceTB/SmolLM2-135M
+datasets:
+  - path: mhenrichsen/alpaca_2k_test
+    type: alpaca
+sequence_len: 2048
+max_steps: 1
+micro_batch_size: 1
+gradient_accumulation_steps: 1
+learning_rate: 1e-3
+special_tokens:
+  pad_token: <|endoftext|>
+"""
+
+
+@pytest.fixture
+def cli_runner():
+    return CliRunner()
+
+
+@pytest.fixture
+def valid_test_config():
+    return VALID_TEST_CONFIG
+
+
+@pytest.fixture
+def config_path(tmp_path):
+    """Creates a temporary config file"""
+    path = tmp_path / "config.yml"
+    path.write_text(VALID_TEST_CONFIG)
+
+    return path