source/tests/unit/train/test_cli_args.py

"""Tests for CLI arguments."""

import argparse

import pytest

from speculators import losses
from speculators.losses import eager
from speculators.models.dflash.core import DFlashDraftModel
from speculators.models.dspark.core import DSparkDraftModel
from speculators.models.eagle3.core import Eagle3DraftModel
from speculators.models.peagle.core import PEagleDraftModel
from speculators.train.config import TrainConfig


def _parse(monkeypatch, extra: list[str]) -> argparse.Namespace:
    cfg = TrainConfig.resolve(["--verifier-name-or-path", "dummy", *extra])
    return argparse.Namespace(**cfg.flatten())


# ---------------------------------------------------------------------------
# Ensure CLI args flow correctly through vars(args) into get_trainer_kwargs
# ---------------------------------------------------------------------------


def test_dflash_default_uses_kl(monkeypatch):
    args = _parse(monkeypatch, [])
    train_kw, val_kw = DFlashDraftModel.get_trainer_kwargs(**vars(args))
    assert "kl_div" in train_kw["loss_config"]
    assert train_kw["loss_config"]["kl_div"][0] is losses.kl_div_loss
    assert "kl_div" in val_kw["loss_config"]
    assert train_kw["gamma"] == 4.0
    assert val_kw["gamma"] == 4.0


def test_dflash_explicit_ce(monkeypatch):
    args = _parse(monkeypatch, ["--loss-fn", "ce"])
    train_kw, val_kw = DFlashDraftModel.get_trainer_kwargs(**vars(args))
    assert "ce" in train_kw["loss_config"]
    assert train_kw["loss_config"]["ce"][0] is losses.ce_loss
    assert "ce" in val_kw["loss_config"]
    assert train_kw["gamma"] == 4.0
    assert val_kw["gamma"] == 4.0


def test_dflash_explicit_decay_gamma(monkeypatch):
    args = _parse(monkeypatch, ["--dflash-decay-gamma", "7.0"])
    train_kw, val_kw = DFlashDraftModel.get_trainer_kwargs(**vars(args))
    assert train_kw["gamma"] == 7.0
    assert val_kw["gamma"] == 7.0


def test_dflash_decay_gamma_falls_back_when_omitted():
    train_kw, val_kw = DFlashDraftModel.get_trainer_kwargs(loss_fn="kl_div")
    assert train_kw["gamma"] == 4.0
    assert val_kw["gamma"] == 4.0


def test_dflash_compound_loss(monkeypatch):
    args = _parse(monkeypatch, ["--loss-fn", '{"ce": 0.1, "tv": 0.9}'])
    train_kw, val_kw = DFlashDraftModel.get_trainer_kwargs(**vars(args))
    assert "ce" in train_kw["loss_config"]
    assert "tv" in train_kw["loss_config"]
    assert train_kw["loss_config"]["ce"][1] == 0.1
    assert train_kw["loss_config"]["tv"][1] == 0.9
    assert "ce" in val_kw["loss_config"]
    assert "tv" in val_kw["loss_config"]


def test_eagle3_default_uses_kl(monkeypatch):
    args = _parse(monkeypatch, [])
    train_kw, val_kw = Eagle3DraftModel.get_trainer_kwargs(**vars(args))
    assert "kl_div" in train_kw["loss_config"]
    assert train_kw["loss_config"]["kl_div"][0] is losses.kl_div_loss
    assert "kl_div" in val_kw["loss_config"]


def test_eagle3_explicit_ce(monkeypatch):
    args = _parse(monkeypatch, ["--loss-fn", "ce"])
    train_kw, val_kw = Eagle3DraftModel.get_trainer_kwargs(**vars(args))
    assert "ce" in train_kw["loss_config"]
    assert train_kw["loss_config"]["ce"][0] is losses.ce_loss
    assert "ce" in val_kw["loss_config"]


def test_peagle_default_uses_kl(monkeypatch):
    args = _parse(monkeypatch, [])
    train_kw, val_kw = PEagleDraftModel.get_trainer_kwargs(**vars(args))
    assert "kl_div" in train_kw["loss_config"]
    assert train_kw["loss_config"]["kl_div"][0] is losses.kl_div_loss
    assert "kl_div" in val_kw["loss_config"]


def test_peagle_explicit_ce(monkeypatch):
    args = _parse(monkeypatch, ["--loss-fn", "ce"])
    train_kw, val_kw = PEagleDraftModel.get_trainer_kwargs(**vars(args))
    assert "ce" in train_kw["loss_config"]
    assert train_kw["loss_config"]["ce"][0] is losses.ce_loss
    assert "ce" in val_kw["loss_config"]


def test_dspark_default_uses_kl(monkeypatch):
    args = _parse(monkeypatch, [])
    train_kw, val_kw = DSparkDraftModel.get_trainer_kwargs(**vars(args))
    assert "kl_div" in train_kw["loss_config"]
    assert train_kw["loss_config"]["kl_div"][0] is losses.kl_div_loss
    assert train_kw["tv_loss_fn"] is losses.tv_loss
    assert "kl_div" in val_kw["loss_config"]
    assert train_kw["confidence_head_alpha"] == 1.0
    assert val_kw["confidence_head_alpha"] == 1.0


def test_dspark_explicit_eager(monkeypatch):
    args = _parse(monkeypatch, ["--loss-implementation", "eager"])
    train_kw, val_kw = DSparkDraftModel.get_trainer_kwargs(**vars(args))
    assert train_kw["loss_config"]["kl_div"][0] is eager.kl_div_loss
    assert train_kw["tv_loss_fn"] is eager.tv_loss
    assert val_kw["tv_loss_fn"] is eager.tv_loss


def test_dspark_compound_loss(monkeypatch):
    args = _parse(monkeypatch, ["--loss-fn", '{"ce": 0.1, "tv": 0.9}'])
    train_kw, val_kw = DSparkDraftModel.get_trainer_kwargs(**vars(args))
    assert "ce" in train_kw["loss_config"]
    assert train_kw["loss_config"]["ce"][0] is losses.ce_loss
    assert train_kw["loss_config"]["ce"][1] == 0.1
    assert "tv" in train_kw["loss_config"]
    assert train_kw["loss_config"]["tv"][0] is losses.tv_loss
    assert train_kw["loss_config"]["tv"][1] == 0.9
    assert "ce" in val_kw["loss_config"]
    assert "tv" in val_kw["loss_config"]


def test_dspark_confidence_head_alpha(monkeypatch):
    args = _parse(monkeypatch, ["--confidence-head-alpha", "0.5"])
    train_kw, val_kw = DSparkDraftModel.get_trainer_kwargs(**vars(args))
    assert train_kw["confidence_head_alpha"] == 0.5
    assert val_kw["confidence_head_alpha"] == 0.5


# ---------------------------------------------------------------------------
# Per-speculator-type defaults for draft_arch, norm_before_fc, norm_output
# ---------------------------------------------------------------------------


def test_eagle3_defaults_to_llama_arch(monkeypatch):
    args = _parse(monkeypatch, [])
    assert args.draft_arch == "llama"


def test_eagle3_defaults_norm_before_fc_true(monkeypatch):
    args = _parse(monkeypatch, [])
    assert args.norm_before_fc is True


def test_eagle3_defaults_norm_output_true(monkeypatch):
    args = _parse(monkeypatch, [])
    assert args.norm_output is True


def test_dflash_defaults_to_qwen3_arch(monkeypatch):
    args = _parse(monkeypatch, ["--speculator-type", "dflash"])
    assert args.draft_arch == "qwen3"


def test_dflash_defaults_norm_before_fc_false(monkeypatch):
    args = _parse(monkeypatch, ["--speculator-type", "dflash"])
    assert args.norm_before_fc is False


def test_dflash_defaults_norm_output_false(monkeypatch):
    args = _parse(monkeypatch, ["--speculator-type", "dflash"])
    assert args.norm_output is False


# ---------------------------------------------------------------------------
# Per-speculator-type defaults for num_layers, per_position_loss_weight, loss_fn
# (best-practices recipe from https://github.com/vllm-project/speculators/issues/979)
# ---------------------------------------------------------------------------


def test_dflash_defaults_num_layers_to_5(monkeypatch):
    args = _parse(monkeypatch, ["--speculator-type", "dflash"])
    assert args.num_layers == 5


def test_dflash_defaults_per_position_loss_weight_to_dpace(monkeypatch):
    args = _parse(monkeypatch, ["--speculator-type", "dflash"])
    assert args.per_position_loss_weight == "dpace"


def test_dflash_defaults_loss_fn_to_ce(monkeypatch):
    args = _parse(monkeypatch, ["--speculator-type", "dflash"])
    assert args.loss_fn == "ce"


def test_dflash_defaults_block_size_to_16(monkeypatch):
    args = _parse(monkeypatch, ["--speculator-type", "dflash"])
    assert args.block_size == 16


def test_dspark_defaults_block_size_to_8(monkeypatch):
    # block_size is shared with dspark, which never had block_size=16 validated.
    args = _parse(monkeypatch, ["--speculator-type", "dspark"])
    assert args.block_size == 8


def test_dflash_explicit_flags_override_new_defaults(monkeypatch):
    args = _parse(
        monkeypatch,
        [
            "--speculator-type",
            "dflash",
            "--num-layers",
            "3",
            "--per-position-loss-weight",
            "fixed-exp-decay",
            "--loss-fn",
            "kl_div",
            "--block-size",
            "8",
        ],
    )
    assert args.num_layers == 3
    assert args.per_position_loss_weight == "fixed-exp-decay"
    assert args.loss_fn == "kl_div"
    assert args.block_size == 8


def test_eagle3_num_layers_and_loss_defaults_unchanged(monkeypatch):
    args = _parse(monkeypatch, [])
    assert args.num_layers == 1
    assert args.per_position_loss_weight == "fixed-exp-decay"
    assert args.loss_fn == "kl_div"
    assert args.block_size == 8


def test_no_norm_before_fc_flag(monkeypatch):
    args = _parse(monkeypatch, ["--no-norm-before-fc"])
    assert args.norm_before_fc is False


def test_no_norm_output_flag(monkeypatch):
    args = _parse(monkeypatch, ["--no-norm-output"])
    assert args.norm_output is False


# ---------------------------------------------------------------------------
# --max-steps
# ---------------------------------------------------------------------------


def test_max_steps_default_is_none(monkeypatch):
    args = _parse(monkeypatch, [])
    assert args.max_steps is None


def test_max_steps_explicit(monkeypatch):
    args = _parse(monkeypatch, ["--max-steps", "15"])
    assert args.max_steps == 15


def test_max_steps_rejects_non_positive(monkeypatch):
    with pytest.raises(SystemExit):
        _parse(monkeypatch, ["--max-steps", "0"])