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giant/tests/test_router.py
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Fix conditioning="physical" so it can actually generalize past training vocab
The whole point of conditioning="physical" is generalizing to a
species/material outside the training menu, but two independent code
paths still hard-required training-vocab membership:

- giant/data/transforms.py: build_cond_features unconditionally raised
  KeyError on an out-of-vocab pdg/material. _vectorized_map_lookup
  gains a strict=False mode (dummy index instead of raising), used only
  under conditioning="physical" where ConditionEncoder never reads
  cond_cat anyway; "embedding" mode is untouched and still raises,
  since cond_cat IS the conditioning signal there.
- giant/rollout.py: the known_pdg termination gate still killed a track
  on step 1 for any pdg outside pdg_map, regardless of conditioning
  mode. Now skipped entirely under conditioning="physical".
- giant/model/network.py: PdgRouter/ProcessRouter always build their
  own training-vocab nn.Embedding independent of conditioning, silently
  reintroducing the same limitation at the routing layer. build_models
  now raises loudly if conditioning="physical" is paired with either
  router type, rather than silently building a model that can't
  generalize the way it claims to.

This unblocks the held-out-species/material generalization experiment
against the multi-material dataset (see CLAUDE.md roadmap). Each fix
has a regression test, including an end-to-end rollout test seeded
with a resolvable-but-out-of-vocab PDG code.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-03 13:47:59 +02:00

1032 lines
34 KiB
Python

"""Tests for the mixture-of-experts routing prototype (giant/model/network.py)."""
import pytest
import torch
from giant.constants import COND_DIM, K_MAX, SEC_DIM, X_DIM
from giant.model.network import (
ComposedRouter,
DenoisingMLP,
EnergyRouter,
PdgRouter,
ProcessRouter,
ROUTER_REGISTRY,
RoutedDenoisingMLP,
RoutedSecondaryDecoder,
SecondaryDecoder,
build_composed_router,
build_models,
build_router,
)
def _cond(B=8, pdg=3, mat=2):
cond_cont = torch.randn(B, COND_DIM)
cond_cat = torch.stack(
[torch.randint(0, pdg, (B,)), torch.randint(0, mat, (B,))], dim=1
)
return cond_cont, cond_cat
def _routed_stage1(n_experts=4, pdg=3, mat=2, **router_kwargs):
router = build_router("energy", n_experts, **router_kwargs)
return RoutedDenoisingMLP(
pdg_vocab=pdg,
mat_vocab=mat,
router=router,
expert_hidden_dim=16,
expert_n_blocks=2,
)
def _routed_sec_decoder(n_experts=4, pdg=3, mat=2, **router_kwargs):
router = build_router("energy", n_experts, **router_kwargs)
return RoutedSecondaryDecoder(
pdg_vocab=pdg,
mat_vocab=mat,
router=router,
expert_hidden_dim=16,
expert_n_blocks=2,
)
# ── Router / EnergyRouter contract ──────────────────────────────────────────
def test_energy_router_registered():
assert ROUTER_REGISTRY["energy"] is EnergyRouter
def test_energy_router_gate_partition_of_unity():
router = EnergyRouter(n_experts=4)
cond_cont, cond_cat = _cond(16)
g = router.gate(cond_cont, cond_cat)
assert g.shape == (16, 4)
torch.testing.assert_close(g.sum(dim=-1), torch.ones(16), atol=1e-5, rtol=0)
def test_energy_router_top1_matches_gate_argmax():
router = EnergyRouter(n_experts=4)
cond_cont, cond_cat = _cond(16)
assert torch.equal(
router.top1(cond_cont, cond_cat), router.gate(cond_cont, cond_cat).argmax(-1)
)
def test_energy_router_hardens_as_temperature_shrinks():
"""As tau -> 0 the soft gate should converge to a one-hot at the argmax."""
router = EnergyRouter(n_experts=4, temperature=1e-4)
cond_cont, cond_cat = _cond(16)
g = router.gate(cond_cont, cond_cat)
top1 = router.top1(cond_cont, cond_cat)
onehot = torch.nn.functional.one_hot(top1, num_classes=4).float()
torch.testing.assert_close(g, onehot, atol=1e-3, rtol=0)
def test_energy_router_balance_loss_is_nonnegative_scalar():
router = EnergyRouter(n_experts=4)
cond_cont, cond_cat = _cond(16)
loss = router.balance_loss(cond_cont, cond_cat)
assert loss.shape == ()
assert loss.item() >= 0.0
def test_build_router_ignores_unrecognized_kwargs():
# lambda_balance is a model_config.router key but not an EnergyRouter kwarg
router = build_router("energy", 4, temperature=0.3, lambda_balance=0.5)
assert isinstance(router, EnergyRouter)
assert router.temperature == 0.3
def test_energy_router_default_centers_are_linspace():
router = EnergyRouter(n_experts=4)
torch.testing.assert_close(router.centers, torch.linspace(-2.0, 2.0, 4))
def test_energy_router_centers_init_overrides_default():
centers_init = [-1.0, 0.0, 0.5, 3.0]
router = EnergyRouter(n_experts=4, centers_init=centers_init)
torch.testing.assert_close(router.centers, torch.tensor(centers_init))
def test_energy_router_centers_init_wrong_length_raises():
try:
EnergyRouter(n_experts=4, centers_init=[0.0, 1.0])
except ValueError:
return
raise AssertionError("expected ValueError for centers_init length mismatch")
def test_energy_router_centers_init_respects_learn_centers_flag():
learned = EnergyRouter(
n_experts=3, centers_init=[-1.0, 0.0, 1.0], learn_centers=True
)
fixed = EnergyRouter(
n_experts=3, centers_init=[-1.0, 0.0, 1.0], learn_centers=False
)
assert isinstance(learned.centers, torch.nn.Parameter)
assert not isinstance(fixed.centers, torch.nn.Parameter)
def test_build_router_threads_centers_init_through_energy_router():
centers_init = [-1.5, -0.5, 0.5, 1.5]
router = build_router("energy", 4, centers_init=centers_init)
torch.testing.assert_close(router.centers, torch.tensor(centers_init))
def test_build_router_unknown_type_raises():
try:
build_router("nonexistent", 4)
except ValueError:
return
raise AssertionError("expected ValueError for unknown router type")
# ── EnergyRouter learn_width / learn_temperature ────────────────────────────
def test_energy_router_learn_width_matches_fixed_temperature_at_init():
"""Enabling learn_width should be a no-op at init — the warm-started
per-expert width must reproduce the fixed-temperature gate exactly."""
centers_init = [-1.0, 0.0, 0.5, 1.5]
fixed = EnergyRouter(n_experts=4, temperature=0.3, centers_init=centers_init)
learned = EnergyRouter(
n_experts=4, temperature=0.3, centers_init=centers_init, learn_width=True
)
cond_cont, cond_cat = _cond(16)
torch.testing.assert_close(
learned.gate(cond_cont, cond_cat),
fixed.gate(cond_cont, cond_cat),
atol=1e-5,
rtol=0,
)
def test_energy_router_learn_temperature_matches_fixed_temperature_at_init():
centers_init = [-1.0, 0.0, 0.5, 1.5]
fixed = EnergyRouter(n_experts=4, temperature=0.3, centers_init=centers_init)
learned = EnergyRouter(
n_experts=4,
temperature=0.3,
centers_init=centers_init,
learn_temperature=True,
)
cond_cont, cond_cat = _cond(16)
torch.testing.assert_close(
learned.gate(cond_cont, cond_cat),
fixed.gate(cond_cont, cond_cat),
atol=1e-5,
rtol=0,
)
def test_energy_router_learn_width_and_temperature_mutually_exclusive_raises():
try:
EnergyRouter(n_experts=4, learn_width=True, learn_temperature=True)
except ValueError:
return
raise AssertionError(
"expected ValueError for learn_width and learn_temperature both set"
)
def test_energy_router_width_ratio_bounds_must_bracket_one_raises():
try:
EnergyRouter(
n_experts=4, learn_width=True, width_min_ratio=1.0, width_max_ratio=2.0
)
except ValueError:
return
raise AssertionError(
"expected ValueError for width_min_ratio/width_max_ratio not bracketing 1.0"
)
def test_energy_router_effective_width_stays_within_bounds():
router = EnergyRouter(
n_experts=4,
temperature=0.5,
learn_width=True,
width_min_ratio=0.1,
width_max_ratio=10.0,
)
lo, hi = 0.1 * 0.5, 10.0 * 0.5
with torch.no_grad():
router.raw_width.fill_(1e6)
width = router.effective_width()
assert isinstance(width, torch.Tensor)
assert torch.all(width <= hi + 1e-4)
with torch.no_grad():
router.raw_width.fill_(-1e6)
width = router.effective_width()
assert isinstance(width, torch.Tensor)
assert torch.all(width >= lo - 1e-4)
def test_energy_router_learn_width_gate_still_partition_of_unity():
router = EnergyRouter(n_experts=4, learn_width=True)
with torch.no_grad():
router.raw_width.copy_(torch.randn(4) * 3)
cond_cont, cond_cat = _cond(16)
g = router.gate(cond_cont, cond_cat)
torch.testing.assert_close(g.sum(dim=-1), torch.ones(16), atol=1e-5, rtol=0)
def test_energy_router_learn_width_hardens_when_pushed_to_floor():
"""Pushing every expert's width toward the (tiny) floor should harden the
gate to a one-hot at the nearest center, generalizing the fixed-
temperature->0 hardening test to the per-expert path."""
router = EnergyRouter(
n_experts=4, learn_width=True, width_min_ratio=1e-4, width_max_ratio=10.0
)
with torch.no_grad():
router.raw_width.fill_(-1e6)
cond_cont, cond_cat = _cond(16)
g = router.gate(cond_cont, cond_cat)
e = cond_cont[:, router.energy_idx].unsqueeze(-1)
d2 = (e - router.centers.unsqueeze(0)) ** 2
onehot = torch.nn.functional.one_hot(d2.argmin(dim=-1), num_classes=4).float()
torch.testing.assert_close(g, onehot, atol=1e-3, rtol=0)
def test_energy_router_own_width_controls_own_coverage_independent_of_others():
"""Widening one expert's width should monotonically grow only that
expert's own gate share, without needing to touch any other expert's
width — the "each expert learns its own coverage independently" property
this feature is meant to add."""
router = EnergyRouter(
n_experts=2, temperature=1.0, learn_width=True, centers_init=[0.0, 10.0]
)
cond_cont, cond_cat = _cond(4)
cond_cont[:, 3] = 3.0 # fixed energy, unequal distance to each center
shares = []
with torch.no_grad():
for raw in torch.linspace(-8.0, 8.0, 9):
router.raw_width[0] = raw
shares.append(router.gate(cond_cont, cond_cat)[0, 0].item())
assert all(a <= b + 1e-6 for a, b in zip(shares, shares[1:]))
def test_build_router_threads_learn_width_kwargs_through():
router = build_router(
"energy", 4, learn_width=True, width_min_ratio=0.2, width_max_ratio=8.0
)
assert isinstance(router, EnergyRouter)
assert router.learn_width is True
assert isinstance(router.raw_width, torch.nn.Parameter)
assert router.raw_width.shape == (4,)
def test_router_entropy_loss_is_nonnegative_bounded_scalar():
router = EnergyRouter(n_experts=4)
cond_cont, cond_cat = _cond(16)
loss = router.entropy_loss(cond_cont, cond_cat)
assert loss.shape == ()
assert 0.0 <= loss.item() <= 1.0
# ── Router.combine_weights (straight-through Gumbel-softmax) ───────────────
def test_combine_weights_defaults_to_gate():
"""gumbel=False (the default) must be a pure pass-through to gate()."""
router = EnergyRouter(n_experts=4)
cond_cont, cond_cat = _cond(16)
torch.testing.assert_close(
router.combine_weights(cond_cont, cond_cat),
router.gate(cond_cont, cond_cat),
)
def test_combine_weights_gumbel_train_mode_is_hard_one_hot():
router = EnergyRouter(n_experts=4)
router.gumbel = True
router.gumbel_tau = 0.5
router.train()
cond_cont, cond_cat = _cond(16)
weights = router.combine_weights(cond_cont, cond_cat)
assert weights.shape == (16, 4)
torch.testing.assert_close(weights.sum(dim=-1), torch.ones(16), atol=1e-5, rtol=0)
assert torch.all((weights.max(dim=-1).values - 1.0).abs() < 1e-5)
def test_combine_weights_gumbel_eval_mode_falls_back_to_gate():
"""No Gumbel noise at eval — combine_weights must match gate() exactly,
same as the gumbel=False path, once the router is in eval mode."""
router = EnergyRouter(n_experts=4)
router.gumbel = True
router.eval()
cond_cont, cond_cat = _cond(16)
torch.testing.assert_close(
router.combine_weights(cond_cont, cond_cat),
router.gate(cond_cont, cond_cat),
)
def test_combine_weights_gumbel_straight_through_gradient_reaches_centers():
router = EnergyRouter(n_experts=4, learn_centers=True)
router.gumbel = True
router.gumbel_tau = 0.5
router.train()
cond_cont, cond_cat = _cond(16)
weights = router.combine_weights(cond_cont, cond_cat)
weights.sum().backward()
assert router.centers.grad is not None
assert torch.any(router.centers.grad != 0.0)
def test_build_router_from_cfg_sets_gumbel_from_config():
from giant.model.network import _build_router_from_cfg
router = _build_router_from_cfg(
{"enabled": True, "type": "energy", "n_experts": 4, "gumbel": True},
pdg_vocab=3,
mat_vocab=2,
)
assert router.gumbel is True
router_off = _build_router_from_cfg(
{"enabled": True, "type": "energy", "n_experts": 4},
pdg_vocab=3,
mat_vocab=2,
)
assert router_off.gumbel is False
def test_build_router_from_cfg_sets_gumbel_for_composed_router():
from giant.model.network import _build_router_from_cfg
router = _build_router_from_cfg(
{
"enabled": True,
"type": "composed",
"gumbel": True,
"axis0_type": "energy",
"axis0_n_experts": 4,
"axis1_type": "pdg",
"axis1_n_experts": 3,
},
pdg_vocab=5,
mat_vocab=2,
)
assert isinstance(router, ComposedRouter)
assert router.gumbel is True
def test_routed_denoising_mlp_forward_runs_with_gumbel_enabled():
"""End-to-end forward through _route_forward's train branch with
straight-through Gumbel-softmax combine weights enabled."""
B = 8
model = _routed_stage1(n_experts=3)
model.router.gumbel = True
model.router.gumbel_tau = 0.5
model.train()
x_t = torch.randn(B, X_DIM)
t = torch.rand(B)
cond_cont, cond_cat = _cond(B)
out = model(x_t, t, cond_cont, cond_cat)
assert out.shape == (B, X_DIM)
assert torch.isfinite(out).all()
# ── PdgRouter ────────────────────────────────────────────────────────────────
def test_pdg_router_registered():
assert ROUTER_REGISTRY["pdg"] is PdgRouter
def test_pdg_router_gate_partition_of_unity():
router = PdgRouter(n_experts=4, pdg_vocab=3)
cond_cont, cond_cat = _cond(16)
g = router.gate(cond_cont, cond_cat)
assert g.shape == (16, 4)
torch.testing.assert_close(g.sum(dim=-1), torch.ones(16), atol=1e-5, rtol=0)
def test_pdg_router_top1_matches_gate_argmax():
router = PdgRouter(n_experts=4, pdg_vocab=3)
cond_cont, cond_cat = _cond(16)
assert torch.equal(
router.top1(cond_cont, cond_cat), router.gate(cond_cont, cond_cat).argmax(-1)
)
def test_pdg_router_hardens_as_temperature_shrinks():
"""As tau -> 0 the soft gate should converge to a one-hot at the argmax."""
router = PdgRouter(n_experts=4, pdg_vocab=3, temperature=1e-4)
cond_cont, cond_cat = _cond(16)
g = router.gate(cond_cont, cond_cat)
top1 = router.top1(cond_cont, cond_cat)
onehot = torch.nn.functional.one_hot(top1, num_classes=4).float()
torch.testing.assert_close(g, onehot, atol=1e-3, rtol=0)
def test_pdg_router_balance_loss_is_nonnegative_scalar():
router = PdgRouter(n_experts=4, pdg_vocab=3)
cond_cont, cond_cat = _cond(16)
loss = router.balance_loss(cond_cont, cond_cat)
assert loss.shape == ()
assert loss.item() >= 0.0
def test_pdg_router_classify_loss_defaults_to_zero():
"""PDG is already known at gate time (unlike ProcessRouter's process
label), so no supervision is needed — falls back to Router's default."""
router = PdgRouter(n_experts=4, pdg_vocab=3)
cond_cont, cond_cat = _cond(16)
labels = torch.randint(0, 4, (16,))
loss = router.classify_loss(cond_cont, cond_cat, labels)
assert loss.shape == ()
assert loss.item() == 0.0
def test_pdg_router_only_reads_pdg_column():
"""Gate must depend on cond_cat[:, 0] (pdg) only, not cond_cont or material."""
router = PdgRouter(n_experts=4, pdg_vocab=3)
cond_cont, cond_cat = _cond(16)
g_before = router.gate(cond_cont, cond_cat)
cond_cont_perturbed = torch.randn_like(cond_cont)
cond_cat_diff_mat = cond_cat.clone()
cond_cat_diff_mat[:, 1] = (cond_cat_diff_mat[:, 1] + 1) % 2
g_after = router.gate(cond_cont_perturbed, cond_cat_diff_mat)
torch.testing.assert_close(g_before, g_after, atol=1e-6, rtol=0)
def test_build_router_pdg_type_uses_pdg_vocab():
router = build_router("pdg", 4, pdg_vocab=5, mat_vocab=3, emb_dim=8)
assert isinstance(router, PdgRouter)
assert router.pdg_emb.num_embeddings == 5
def test_build_models_routed_with_pdg_router():
model_config = dict(
pdg_vocab=4,
mat_vocab=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
expert_hidden_dim=16,
expert_n_blocks=2,
router={
"enabled": True,
"type": "pdg",
"n_experts": 3,
},
)
stage1, sec_decoder = build_models(model_config)
assert isinstance(stage1, RoutedDenoisingMLP)
assert isinstance(stage1.router, PdgRouter)
assert len(stage1.experts) == 3
assert stage1.router.pdg_emb.num_embeddings == 4
def test_build_models_rejects_pdg_router_with_physical_conditioning():
"""conditioning="physical" is meant to generalize beyond the training PDG
vocab; PdgRouter always uses a training-vocab nn.Embedding regardless of
conditioning, so the combination must raise rather than silently building
a model that can't actually generalize the way it claims to."""
model_config = dict(
pdg_vocab=4,
mat_vocab=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
expert_hidden_dim=16,
expert_n_blocks=2,
conditioning="physical",
router={"enabled": True, "type": "pdg", "n_experts": 3},
)
with pytest.raises(ValueError, match="physical"):
build_models(model_config)
def test_build_models_rejects_composed_router_with_pdg_axis_and_physical_conditioning():
model_config = dict(
pdg_vocab=4,
mat_vocab=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
expert_hidden_dim=16,
expert_n_blocks=2,
conditioning="physical",
router={
"enabled": True,
"type": "composed",
"axis0_type": "energy",
"axis0_n_experts": 2,
"axis1_type": "pdg",
"axis1_n_experts": 3,
},
)
with pytest.raises(ValueError, match="physical"):
build_models(model_config)
# ── ProcessRouter ────────────────────────────────────────────────────────────
def test_process_router_registered():
assert ROUTER_REGISTRY["process"] is ProcessRouter
def test_process_router_gate_partition_of_unity():
router = ProcessRouter(n_experts=4, pdg_vocab=3, mat_vocab=2)
cond_cont, cond_cat = _cond(16)
g = router.gate(cond_cont, cond_cat)
assert g.shape == (16, 4)
torch.testing.assert_close(g.sum(dim=-1), torch.ones(16), atol=1e-5, rtol=0)
def test_process_router_top1_matches_gate_argmax():
router = ProcessRouter(n_experts=4, pdg_vocab=3, mat_vocab=2)
cond_cont, cond_cat = _cond(16)
assert torch.equal(
router.top1(cond_cont, cond_cat), router.gate(cond_cont, cond_cat).argmax(-1)
)
def test_process_router_balance_loss_is_nonnegative_scalar():
router = ProcessRouter(n_experts=4, pdg_vocab=3, mat_vocab=2)
cond_cont, cond_cat = _cond(16)
loss = router.balance_loss(cond_cont, cond_cat)
assert loss.shape == ()
assert loss.item() >= 0.0
def test_process_router_classify_loss_decreases_with_training():
"""The classifier should be able to fit an arbitrary label assignment —
a sanity check that gradients actually flow to the process classifier."""
torch.manual_seed(0)
router = ProcessRouter(n_experts=4, pdg_vocab=3, mat_vocab=2)
cond_cont, cond_cat = _cond(32)
labels = torch.randint(0, 4, (32,))
opt = torch.optim.Adam(router.parameters(), lr=0.05)
first = router.classify_loss(cond_cont, cond_cat, labels).item()
for _ in range(50):
opt.zero_grad()
loss = router.classify_loss(cond_cont, cond_cat, labels)
loss.backward()
opt.step()
last = loss.item()
assert last < first
def test_energy_router_classify_loss_defaults_to_zero():
"""Routers with no supervised signal (EnergyRouter) fall back to the
Router base class's zero-loss default."""
router = EnergyRouter(n_experts=4)
cond_cont, cond_cat = _cond(16)
labels = torch.randint(0, 4, (16,))
loss = router.classify_loss(cond_cont, cond_cat, labels)
assert loss.shape == ()
assert loss.item() == 0.0
def test_build_router_process_type_uses_pdg_mat_vocab():
router = build_router("process", 4, pdg_vocab=5, mat_vocab=3, emb_dim=8)
assert isinstance(router, ProcessRouter)
assert router.pdg_emb.num_embeddings == 5
assert router.mat_emb.num_embeddings == 3
def test_build_models_routed_with_process_router():
model_config = dict(
pdg_vocab=4,
mat_vocab=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
expert_hidden_dim=16,
expert_n_blocks=2,
router={
"enabled": True,
"type": "process",
"n_experts": 3,
"lambda_proc": 1.0,
},
)
stage1, sec_decoder = build_models(model_config)
assert isinstance(stage1, RoutedDenoisingMLP)
assert isinstance(stage1.router, ProcessRouter)
assert len(stage1.experts) == 3
assert stage1.router.pdg_emb.num_embeddings == 4
assert stage1.router.mat_emb.num_embeddings == 2
# ── ComposedRouter ───────────────────────────────────────────────────────────
def test_composed_router_n_experts_is_product():
router = ComposedRouter(
[EnergyRouter(n_experts=4), PdgRouter(n_experts=3, pdg_vocab=5)]
)
assert router.n_experts == 12
def test_composed_router_gate_partition_of_unity():
router = ComposedRouter(
[EnergyRouter(n_experts=4), PdgRouter(n_experts=3, pdg_vocab=5)]
)
cond_cont, cond_cat = _cond(16, pdg=5)
g = router.gate(cond_cont, cond_cat)
assert g.shape == (16, 12)
torch.testing.assert_close(g.sum(dim=-1), torch.ones(16), atol=1e-5, rtol=0)
def test_composed_router_gate_is_outer_product_of_sub_gates():
energy_router = EnergyRouter(n_experts=4)
pdg_router = PdgRouter(n_experts=3, pdg_vocab=5)
router = ComposedRouter([energy_router, pdg_router])
cond_cont, cond_cat = _cond(16, pdg=5)
g_energy = energy_router.gate(cond_cont, cond_cat) # (16, 4)
g_pdg = pdg_router.gate(cond_cont, cond_cat) # (16, 3)
expected = (g_energy.unsqueeze(-1) * g_pdg.unsqueeze(1)).flatten(1) # (16, 12)
torch.testing.assert_close(router.gate(cond_cont, cond_cat), expected)
def test_composed_router_top1_factors_into_per_axis_argmax():
"""Joint argmax over the outer product must equal the pair of per-axis
argmaxes, flattened with the same row-major index convention as gate()."""
energy_router = EnergyRouter(n_experts=4)
pdg_router = PdgRouter(n_experts=3, pdg_vocab=5)
router = ComposedRouter([energy_router, pdg_router])
cond_cont, cond_cat = _cond(16, pdg=5)
joint_idx = router.top1(cond_cont, cond_cat)
energy_idx = energy_router.top1(cond_cont, cond_cat)
pdg_idx = pdg_router.top1(cond_cont, cond_cat)
expected = energy_idx * pdg_router.n_experts + pdg_idx
assert torch.equal(joint_idx, expected)
def test_composed_router_supports_different_expert_counts_per_axis():
router = ComposedRouter(
[EnergyRouter(n_experts=5), PdgRouter(n_experts=2, pdg_vocab=5)]
)
assert router.n_experts == 10
cond_cont, cond_cat = _cond(8, pdg=5)
assert router.gate(cond_cont, cond_cat).shape == (8, 10)
def test_composed_router_classify_loss_sums_sub_router_losses():
"""energy/pdg both default to zero, so the composed loss should too."""
router = ComposedRouter(
[EnergyRouter(n_experts=4), PdgRouter(n_experts=3, pdg_vocab=5)]
)
cond_cont, cond_cat = _cond(16, pdg=5)
labels = torch.randint(0, 4, (16,))
loss = router.classify_loss(cond_cont, cond_cat, labels)
assert loss.shape == ()
assert loss.item() == 0.0
def test_composed_router_rejects_empty_router_list():
try:
ComposedRouter([])
except ValueError:
return
raise AssertionError("expected ValueError for empty router list")
def test_composed_router_not_in_registry():
assert "composed" not in ROUTER_REGISTRY
# ── _parse_composed_axes (axis{i}_{field} flat-key config convention) ───────
def test_parse_composed_axes_groups_indexed_keys():
from giant.model.network import _parse_composed_axes
router_cfg = {
"enabled": True,
"type": "composed",
"axis0_type": "energy",
"axis0_n_experts": 4,
"axis0_temperature": 0.3,
"axis1_type": "pdg",
"axis1_n_experts": 3,
"axis1_emb_dim": 6,
}
axes = _parse_composed_axes(router_cfg)
assert axes == [
{"type": "energy", "n_experts": 4, "temperature": 0.3},
{"type": "pdg", "n_experts": 3, "emb_dim": 6},
]
def test_parse_composed_axes_ignores_unrelated_keys():
from giant.model.network import _parse_composed_axes
router_cfg = {
"enabled": True,
"type": "composed",
"lambda_balance": 0.0,
"axis0_type": "energy",
"axis0_n_experts": 4,
}
axes = _parse_composed_axes(router_cfg)
assert axes == [{"type": "energy", "n_experts": 4}]
def test_parse_composed_axes_raises_on_index_gap():
from giant.model.network import _parse_composed_axes
router_cfg = {
"type": "composed",
"axis0_type": "energy",
"axis0_n_experts": 4,
# axis1 missing entirely
"axis2_type": "pdg",
"axis2_n_experts": 3,
}
try:
_parse_composed_axes(router_cfg)
except ValueError:
return
raise AssertionError("expected ValueError for a gap in axis indices")
def test_build_composed_router_resolves_per_axis_specs():
router = build_composed_router(
[
{"type": "energy", "n_experts": 4, "temperature": 0.3},
{"type": "pdg", "n_experts": 3, "emb_dim": 6},
],
pdg_vocab=5,
mat_vocab=2,
)
assert isinstance(router, ComposedRouter)
assert router.n_experts == 12
energy_router, pdg_router = router.routers
assert isinstance(energy_router, EnergyRouter)
assert energy_router.temperature == 0.3
assert isinstance(pdg_router, PdgRouter)
assert pdg_router.pdg_emb.num_embeddings == 5
assert pdg_router.pdg_emb.embedding_dim == 6
def test_build_models_routed_with_composed_router():
model_config = dict(
pdg_vocab=5,
mat_vocab=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
expert_hidden_dim=16,
expert_n_blocks=2,
router={
"enabled": True,
"type": "composed",
"axis0_type": "energy",
"axis0_n_experts": 4,
"axis1_type": "pdg",
"axis1_n_experts": 3,
},
)
stage1, sec_decoder = build_models(model_config)
assert isinstance(stage1, RoutedDenoisingMLP)
assert isinstance(stage1.router, ComposedRouter)
assert len(stage1.experts) == 12
assert len(sec_decoder.experts) == 12
# stage1 and sec_decoder must not share router weights (same convention
# as the single-axis routers built by build_models).
assert stage1.router is not sec_decoder.router
def test_build_models_routed_pair_composed_router_is_drop_in_for_sample_flow():
from giant.sample import sample_flow, sample_secondaries
model_config = dict(
pdg_vocab=3,
mat_vocab=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
expert_hidden_dim=8,
expert_n_blocks=1,
router={
"enabled": True,
"type": "composed",
"axis0_type": "energy",
"axis0_n_experts": 2,
"axis1_type": "pdg",
"axis1_n_experts": 2,
},
)
stage1, sec_decoder = build_models(model_config)
B = 5
cond_cont, cond_cat = _cond(B, pdg=3, mat=2)
stage1_norm, n_sec_pred = sample_flow(stage1, cond_cont, cond_cat, steps=2)
assert stage1_norm.shape == (B, X_DIM)
assert n_sec_pred.shape == (B,)
sec_cont, sec_type_emb, sec_valid = sample_secondaries(
sec_decoder, cond_cont, cond_cat, stage1_norm, n_sec_pred, steps=2
)
assert sec_cont.shape == (B, K_MAX, 4)
assert sec_valid.shape == (B, K_MAX)
# ── RoutedDenoisingMLP ───────────────────────────────────────────────────────
def test_routed_denoising_mlp_output_shape_train_and_eval():
B = 8
model = _routed_stage1()
x_t = torch.randn(B, X_DIM)
t = torch.rand(B)
cond_cont, cond_cat = _cond(B)
model.train()
out_train = model(x_t, t, cond_cont, cond_cat)
assert out_train.shape == (B, X_DIM)
model.eval()
with torch.no_grad():
out_eval = model(x_t, t, cond_cont, cond_cat)
assert out_eval.shape == (B, X_DIM)
def test_routed_denoising_mlp_gradients_flow_in_train_mode():
"""Soft mixture in train mode should touch every expert's parameters."""
B = 8
model = _routed_stage1(n_experts=3)
x_t = torch.randn(B, X_DIM)
t = torch.rand(B)
cond_cont, cond_cat = _cond(B)
model.train()
flow_loss = model(x_t, t, cond_cont, cond_cat).sum()
nsec_loss = model.predict_n_sec(cond_cont, cond_cat).sum()
(flow_loss + nsec_loss).backward()
for name, p in model.named_parameters():
assert p.grad is not None, f"no grad for {name}"
def test_routed_denoising_mlp_eval_dispatch_matches_manual_grouping():
"""Eval-mode grouped top-1 dispatch must equal running each row through
its assigned expert individually (batch order shouldn't matter)."""
B = 12
model = _routed_stage1(n_experts=4)
model.eval()
x_t = torch.randn(B, X_DIM)
t = torch.rand(B)
cond_cont, cond_cat = _cond(B)
with torch.no_grad():
batched = model(x_t, t, cond_cont, cond_cat)
t_emb = model.time_emb(t)
c_emb = model.cond_enc(cond_cont, cond_cat)
cond = torch.cat([t_emb, c_emb], dim=-1)
idx = model.router.top1(cond_cont, cond_cat)
manual = torch.zeros_like(x_t)
for i in range(B):
manual[i] = model.experts[int(idx[i])](x_t[i : i + 1], cond[i : i + 1])[0]
torch.testing.assert_close(batched, manual, atol=1e-5, rtol=1e-4)
def test_routed_denoising_mlp_predict_n_sec_shape():
B = 6
model = _routed_stage1()
cond_cont, cond_cat = _cond(B)
logits = model.predict_n_sec(cond_cont, cond_cat)
assert logits.shape == (B, K_MAX + 1)
def test_routed_denoising_mlp_has_no_pdg_embedding_weight_method():
model = _routed_stage1(pdg=5, mat=2)
assert not hasattr(model, "pdg_embedding_weight")
# ── RoutedSecondaryDecoder ───────────────────────────────────────────────────
def test_routed_secondary_decoder_output_shape_train_and_eval():
B = 8
decoder = _routed_sec_decoder()
x_t = torch.randn(B, SEC_DIM)
t = torch.rand(B)
cond_cont, cond_cat = _cond(B)
stage1_out = torch.randn(B, X_DIM)
decoder.train()
out_train = decoder(x_t, t, cond_cont, cond_cat, stage1_out)
assert out_train.shape == (B, SEC_DIM)
decoder.eval()
with torch.no_grad():
out_eval = decoder(x_t, t, cond_cont, cond_cat, stage1_out)
assert out_eval.shape == (B, SEC_DIM)
def test_routed_secondary_decoder_gradients_flow():
B = 4
decoder = _routed_sec_decoder(n_experts=3)
x_t = torch.randn(B, SEC_DIM)
t = torch.rand(B)
cond_cont, cond_cat = _cond(B)
stage1_out = torch.randn(B, X_DIM)
decoder.train()
decoder(x_t, t, cond_cont, cond_cat, stage1_out).sum().backward()
for name, p in decoder.named_parameters():
assert p.grad is not None, f"no grad for {name}"
# ── build_models dispatch ────────────────────────────────────────────────────
def test_build_models_monolith_when_router_absent():
model_config = dict(
pdg_vocab=4,
mat_vocab=2,
hidden_dim=32,
n_blocks=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
)
stage1, sec_decoder = build_models(model_config)
assert isinstance(stage1, DenoisingMLP)
assert isinstance(sec_decoder, SecondaryDecoder)
def test_build_models_monolith_when_router_disabled():
model_config = dict(
pdg_vocab=4,
mat_vocab=2,
hidden_dim=32,
n_blocks=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
router={"enabled": False, "type": "energy", "n_experts": 4},
)
stage1, sec_decoder = build_models(model_config)
assert isinstance(stage1, DenoisingMLP)
assert isinstance(sec_decoder, SecondaryDecoder)
def test_build_models_routed_when_enabled():
model_config = dict(
pdg_vocab=4,
mat_vocab=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
expert_hidden_dim=16,
expert_n_blocks=2,
router={
"enabled": True,
"type": "energy",
"n_experts": 4,
"temperature": 0.5,
"learn_centers": True,
"lambda_balance": 0.0,
},
)
stage1, sec_decoder = build_models(model_config)
assert isinstance(stage1, RoutedDenoisingMLP)
assert isinstance(sec_decoder, RoutedSecondaryDecoder)
assert len(stage1.experts) == 4
assert len(sec_decoder.experts) == 4
def test_build_models_routed_pair_is_drop_in_for_sample_flow():
"""Exercise the exact calling convention giant/sample.py uses."""
from giant.sample import sample_flow, sample_secondaries
model_config = dict(
pdg_vocab=3,
mat_vocab=2,
emb_dim=16,
dropout=0.1,
k_max=K_MAX,
expert_hidden_dim=8,
expert_n_blocks=1,
router={"enabled": True, "type": "energy", "n_experts": 2},
)
stage1, sec_decoder = build_models(model_config)
B = 5
cond_cont, cond_cat = _cond(B, pdg=3, mat=2)
stage1_norm, n_sec_pred = sample_flow(stage1, cond_cont, cond_cat, steps=2)
assert stage1_norm.shape == (B, X_DIM)
assert n_sec_pred.shape == (B,)
sec_cont, sec_type_emb, sec_valid = sample_secondaries(
sec_decoder, cond_cont, cond_cat, stage1_norm, n_sec_pred, steps=2
)
assert sec_cont.shape == (B, K_MAX, 4)
assert sec_valid.shape == (B, K_MAX)