def test_error_on_dataloader_passed_to_fit(tmp_path):
    """Verify that when the auto-scale batch size feature raises an error if a train dataloader is passed to fit."""

    # only train passed to fit
    model = BatchSizeModel(batch_size=2)
    trainer = Trainer(
        default_root_dir=tmp_path,
        max_epochs=1,
        limit_val_batches=0.1,
        limit_train_batches=0.2,
    )
    tuner = Tuner(trainer)

    with pytest.raises(
        MisconfigurationException,
        match="Batch size finder cannot be used with dataloaders passed directly",
    ):
        tuner.scale_batch_size(model, train_dataloaders=model.train_dataloader(), mode="power")
Verify that when the auto-scale batch size feature raises an error if a train dataloader is passed to fit.
tests/tests_pytorch/tuner/test_scale_batch_size.py