lightning/tests/tests_fabric/utilities/test_imports.py

64 lines
2.0 KiB
Python

# Copyright The PyTorch Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import subprocess
import sys
from textwrap import dedent
from tests_fabric.helpers.runif import RunIf
from lightning_fabric.strategies.deepspeed import _DEEPSPEED_AVAILABLE
def test_imports():
try:
import deepspeed # noqa
except ModuleNotFoundError:
assert not _DEEPSPEED_AVAILABLE
else:
assert _DEEPSPEED_AVAILABLE
def test_import_fabric_with_torch_dist_unavailable():
"""Test that the package can be imported regardless of whether torch.distributed is available."""
code = dedent(
"""
import torch
torch.distributed.is_available = lambda: False # pretend torch.distributed not available
import lightning_fabric
"""
)
# run in complete isolation
assert subprocess.call([sys.executable, "-c", code]) == 0
@RunIf(deepspeed=True)
def test_import_deepspeed_lazily():
"""Test that we are importing deepspeed only when necessary."""
code = dedent(
"""
import lightning_fabric
import sys
assert 'deepspeed' not in sys.modules
from lightning_fabric.strategies import DeepSpeedStrategy
from lightning_fabric.plugins import DeepSpeedPrecision
assert 'deepspeed' not in sys.modules
import deepspeed
assert 'deepspeed' in sys.modules
"""
)
# run in complete isolation
assert subprocess.call([sys.executable, "-c", code]) == 0