Files
AstrAI/tests/trainer/test_loss_output.py
T
ViperEkura 020e2eff4e refactor: emit strategy metrics as floats
- Converts detached strategy metrics before returning loss output
- Removes redundant item conversion from the trainer loop
- Updates the documented contract and regression tests
2026-08-02 06:38:28 +08:00

106 lines
3.0 KiB
Python

from types import SimpleNamespace
import pytest
import torch
from astrai.model.transformer import AutoRegressiveLM
from astrai.trainer.strategy import BaseStrategy, SEQStrategy
from astrai.trainer.train_callback import MetricCallback
from tests.helpers import make_tiny_config
def test_seq_strategy_combines_and_reports_moe_aux_loss(device):
config = make_tiny_config(
ffn_type="moe",
n_routed_experts=4,
n_shared_experts=1,
n_activated_experts=2,
topk_method="greedy",
)
model = AutoRegressiveLM(config).to(device=device)
strategy = SEQStrategy(model, device, moe_aux_loss_coef=0.25)
batch = {
"input_ids": torch.randint(0, config.vocab_size, (2, 8), device=device),
"target_ids": torch.randint(0, config.vocab_size, (2, 8), device=device),
}
output = strategy(batch)
legacy_loss = strategy.compute_loss(batch)
assert isinstance(legacy_loss, torch.Tensor)
assert set(output["metrics"]) == {
"loss",
"task_loss",
"moe_aux_loss",
"moe_aux_loss_weighted",
}
assert output["loss"].item() == pytest.approx(
output["metrics"]["task_loss"] + output["metrics"]["moe_aux_loss_weighted"],
)
assert output["metrics"]["moe_aux_loss_weighted"] == pytest.approx(
0.25 * output["metrics"]["moe_aux_loss"],
)
assert output["loss"].requires_grad
assert all(isinstance(metric, float) for metric in output["metrics"].values())
def test_metric_callback_includes_dynamic_strategy_metrics(tmp_path):
callback = MetricCallback(
ckpt_dir=tmp_path,
save_interval=1,
metrics=["loss", "lr"],
)
context = SimpleNamespace(
metrics={"task_loss": 2.0, "moe_aux_loss": 1.0},
loss=2.01,
optimizer=SimpleNamespace(param_groups=[{"lr": 1e-3}]),
val_loss=None,
grad_norm=None,
grad_snr_tracker=None,
world_size=1,
)
metrics = callback._metrics(context, callback.metrics)
assert metrics == {
"loss": 2.01,
"lr": 1e-3,
"task_loss": 2.0,
"moe_aux_loss": 1.0,
}
def test_metric_callback_only_computes_requested_metrics(tmp_path):
def fail_metric(context):
_ = context
raise AssertionError("unrequested metric was computed")
callback = MetricCallback(
ckpt_dir=tmp_path,
save_interval=1,
metrics=["loss"],
)
callback._metric_funcs["grad_snr"] = fail_metric
context = SimpleNamespace(
metrics={},
loss=2.0,
world_size=1,
)
metrics = callback._metrics(context, callback.metrics)
assert metrics == {"loss": 2.0}
def test_legacy_strategy_tensor_loss_is_normalized():
class LegacyStrategy(BaseStrategy):
def compute_loss(self, batch):
return torch.tensor(2.0, requires_grad=True)
strategy = LegacyStrategy(torch.nn.Linear(1, 1), "cpu")
output = strategy({})
assert output["loss"].item() == 2.0
assert output["metrics"]["loss"] == 2.0