unsloth/studio/backend/tests/test_diffusion_lora_trainer.py

347 lines
13 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-only
# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
"""CPU-only unit tests for the diffusion LoRA trainer's pure helpers.
The training loop needs a GPU + weights, but dataset discovery, config normalisation,
the SDXL add-time-ids, and the dict->config adapter are pure and tested here.
"""
from __future__ import annotations
import json
import pytest
from core.training.diffusion_lora_trainer import (
DEFAULT_LORA_TARGETS,
DiffusionLoraConfig,
_coerce_gradient_checkpointing,
_config_from_dict,
compute_sdxl_add_time_ids,
discover_image_caption_pairs,
)
def _touch(p):
p.write_bytes(b"")
def test_discover_prefers_sidecar_then_metadata_then_instance(tmp_path):
_touch(tmp_path / "a.png")
_touch(tmp_path / "b.jpg")
_touch(tmp_path / "c.webp")
# a.png captioned via metadata.jsonl only
(tmp_path / "metadata.jsonl").write_text(
json.dumps({"file_name": "a.png", "text": "from metadata"}) + "\n", encoding = "utf-8"
)
# b.jpg captioned via sidecar only
(tmp_path / "b.txt").write_text("from sidecar", encoding = "utf-8")
# c.webp falls back to the instance prompt
pairs = dict(discover_image_caption_pairs(tmp_path, instance_prompt = "from instance"))
assert pairs[str(tmp_path / "a.png")] == "from metadata"
assert pairs[str(tmp_path / "b.jpg")] == "from sidecar"
assert pairs[str(tmp_path / "c.webp")] == "from instance"
def test_discover_sidecar_overrides_metadata_row(tmp_path):
# A per-image sidecar is the user's explicit edit and must win over a metadata row
# for the same image (the labeling grid writes sidecars).
_touch(tmp_path / "a.png")
(tmp_path / "metadata.jsonl").write_text(
json.dumps({"file_name": "a.png", "text": "from metadata"}) + "\n", encoding = "utf-8"
)
(tmp_path / "a.txt").write_text("edited sidecar", encoding = "utf-8")
pairs = dict(discover_image_caption_pairs(tmp_path))
assert pairs[str(tmp_path / "a.png")] == "edited sidecar"
def test_discover_skips_uncaptioned_without_instance_prompt(tmp_path):
_touch(tmp_path / "cap.png")
_touch(tmp_path / "nocap.png")
(tmp_path / "cap.caption").write_text("a caption", encoding = "utf-8")
pairs = discover_image_caption_pairs(tmp_path)
assert pairs == [(str(tmp_path / "cap.png"), "a caption")]
def test_discover_captions_jsonl_and_image_key(tmp_path):
_touch(tmp_path / "x.png")
(tmp_path / "captions.jsonl").write_text(
json.dumps({"image": "x.png", "text": "hi"}) + "\n", encoding = "utf-8"
)
assert discover_image_caption_pairs(tmp_path) == [(str(tmp_path / "x.png"), "hi")]
def test_discover_custom_caption_column(tmp_path):
_touch(tmp_path / "x.png")
(tmp_path / "metadata.jsonl").write_text(
json.dumps({"file_name": "x.png", "caption": "col"}) + "\n", encoding = "utf-8"
)
assert discover_image_caption_pairs(tmp_path, caption_column = "caption")[0][1] == "col"
def test_discover_empty_raises(tmp_path):
_touch(tmp_path / "x.png") # no captions anywhere, no instance prompt
with pytest.raises(ValueError, match = "No captioned images"):
discover_image_caption_pairs(tmp_path)
def test_discover_missing_dir_raises(tmp_path):
with pytest.raises(FileNotFoundError):
discover_image_caption_pairs(tmp_path / "nope")
def test_config_normalized_defaults():
cfg = DiffusionLoraConfig(base_model = "b", data_dir = "d", output_dir = "o").normalized()
assert cfg.lora_alpha == cfg.lora_rank # alpha defaults to rank
assert cfg.lora_target_modules == DEFAULT_LORA_TARGETS
@pytest.mark.parametrize(
"kw",
[
{"train_steps": 0},
{"train_batch_size": 0},
{"gradient_accumulation_steps": 0},
{"lora_rank": 0},
{"resolution": 100}, # not a multiple of 8
{"resolution": 32}, # too small
{"mixed_precision": "int4"},
],
)
def test_config_normalized_validation(kw):
with pytest.raises(ValueError):
DiffusionLoraConfig(base_model = "b", data_dir = "d", output_dir = "o", **kw).normalized()
def test_compute_sdxl_add_time_ids():
assert compute_sdxl_add_time_ids(1024) == (1024, 1024, 0, 0, 1024, 1024)
def test_config_from_dict_ignores_unknown_and_tuples_targets():
cfg = _config_from_dict(
{
"base_model": "b",
"data_dir": "d",
"output_dir": "o",
"lora_target_modules": ["to_q", "to_v"],
"unknown_field": 123, # must be ignored, not crash
}
)
assert cfg.lora_target_modules == ("to_q", "to_v")
assert not hasattr(cfg, "unknown_field")
def test_config_rejects_zero_lora_alpha():
# An explicit zero alpha would scale the adapter to nothing; reject it.
with pytest.raises(ValueError, match = "lora_alpha"):
DiffusionLoraConfig(base_model = "b", data_dir = "d", output_dir = "o", lora_alpha = 0).normalized()
def test_config_rejects_nonpositive_snr_gamma():
# gamma <= 0 zeroes/inverts the min-SNR weight; None is the documented disable.
with pytest.raises(ValueError, match = "snr_gamma"):
DiffusionLoraConfig(base_model = "b", data_dir = "d", output_dir = "o", snr_gamma = 0).normalized()
cfg = DiffusionLoraConfig(
base_model = "b", data_dir = "d", output_dir = "o", snr_gamma = None
).normalized()
assert cfg.snr_gamma is None
def test_config_coerces_string_learning_rate():
# The Studio config path preserves learning_rate as a string; normalize to float.
cfg = DiffusionLoraConfig(
base_model = "b", data_dir = "d", output_dir = "o", learning_rate = "1e-4"
).normalized()
assert cfg.learning_rate == 1e-4
with pytest.raises(ValueError, match = "learning_rate"):
DiffusionLoraConfig(
base_model = "b", data_dir = "d", output_dir = "o", learning_rate = "abc"
).normalized()
def test_config_blank_hf_token_is_anonymous():
cfg = DiffusionLoraConfig(
base_model = "b", data_dir = "d", output_dir = "o", hf_token = " "
).normalized()
assert cfg.hf_token is None
def test_config_from_dict_aliases_generic_studio_keys():
# The generic Studio training payload uses different key names; alias them.
cfg = _config_from_dict(
{
"model_name": "b",
"data_dir": "d",
"output_dir": "o",
"max_steps": 25,
"batch_size": 3,
"lora_r": 8,
"lr_scheduler_type": "cosine",
"random_seed": 7,
}
)
assert cfg.base_model == "b"
assert cfg.train_steps == 25
assert cfg.train_batch_size == 3
assert cfg.lora_rank == 8
assert cfg.lr_scheduler == "cosine"
assert cfg.seed == 7
def test_config_from_dict_canonical_key_beats_alias():
cfg = _config_from_dict(
{"base_model": "canon", "model_name": "alias", "data_dir": "d", "output_dir": "o"}
)
assert cfg.base_model == "canon"
def test_gradient_checkpointing_string_coercion():
# Studio sends a string; the disable words are False, everything else truthy True.
for off in ("none", "None", "false", "0", "no", "off", ""):
assert _coerce_gradient_checkpointing(off) is False
for on in ("true", "unsloth", "yes"):
assert _coerce_gradient_checkpointing(on) is True
assert _coerce_gradient_checkpointing(True) is True
assert _coerce_gradient_checkpointing(False) is False
cfg = _config_from_dict(
{"base_model": "b", "data_dir": "d", "output_dir": "o", "gradient_checkpointing": "none"}
)
assert cfg.gradient_checkpointing is False
def test_config_rejects_nonpositive_learning_rate():
with pytest.raises(ValueError, match = "learning_rate"):
DiffusionLoraConfig(
base_model = "b", data_dir = "d", output_dir = "o", learning_rate = 0
).normalized()
def test_config_rejects_untrainable_base_models():
# GGUF checkpoints and families without a trainer (Kontext editing, SD3) must fail at
# normalise time (an instant 400 via the API), not minutes later inside from_pretrained.
for bad in (
"unsloth/FLUX.1-dev-GGUF",
"z-image-turbo-Q4_K_M.gguf",
"stabilityai/stable-diffusion-3-medium",
"unsloth/FLUX.1-Kontext-dev",
):
with pytest.raises(ValueError):
DiffusionLoraConfig(base_model = bad, data_dir = "d", output_dir = "o").normalized()
def test_config_resolves_dit_families():
# FLUX.1 / Qwen-Image / Z-Image bases now resolve to their DiT trainer families.
for base, fam in (
("black-forest-labs/FLUX.1-dev", "flux.1"),
("black-forest-labs/FLUX.1-schnell", "flux.1"),
("unsloth/Qwen-Image-2512-unsloth-bnb-4bit", "qwen-image"),
("Tongyi-MAI/Z-Image-Turbo", "z-image"),
):
cfg = DiffusionLoraConfig(base_model = base, data_dir = "d", output_dir = "o").normalized()
assert cfg.resolved_family == fam
def test_config_accepts_sdxl_and_unknown_base_models():
# SDXL names and unclassifiable custom names/paths must pass the guard (a wrong
# custom pick still fails cleanly in from_pretrained).
for ok in (
"stabilityai/stable-diffusion-xl-base-1.0",
"stabilityai/sdxl-turbo",
"/data/checkpoints/my-custom-sdxl",
"my-finetune",
):
cfg = DiffusionLoraConfig(base_model = ok, data_dir = "d", output_dir = "o").normalized()
assert cfg.base_model == ok
# ── trainer registry + family resolution + metadata sidecar (PR A platform) ──
def test_get_trainer_resolves_sdxl():
from core.training.diffusion_lora_trainer import get_trainer, run_diffusion_lora_training
assert get_trainer("sdxl") is run_diffusion_lora_training
assert get_trainer("SDXL") is run_diffusion_lora_training # case-insensitive
def test_get_trainer_unknown_family_raises():
from core.training.diffusion_lora_trainer import get_trainer
with pytest.raises(ValueError, match = "No trainer"):
get_trainer("flux.2-dev") # a real family with no registered trainer
def test_get_trainer_resolves_dit_families():
from core.training.diffusion_dit_trainer import run_dit_lora_training
from core.training.diffusion_lora_trainer import get_trainer
for fam in ("flux.1", "qwen-image", "z-image"):
assert get_trainer(fam) is run_dit_lora_training
def test_normalized_sets_resolved_family():
cfg = DiffusionLoraConfig(
base_model = "stabilityai/stable-diffusion-xl-base-1.0", data_dir = "d", output_dir = "o"
).normalized()
assert cfg.resolved_family == "sdxl"
cfg2 = DiffusionLoraConfig(
base_model = "my-custom-thing", data_dir = "d", output_dir = "o"
).normalized()
assert cfg2.resolved_family == "sdxl" # unknown -> default SDXL trainer
def test_explicit_model_family_validated():
from core.training.diffusion_lora_trainer import DiffusionLoraConfig as C
# A bogus explicit family is rejected up front.
with pytest.raises(ValueError, match = "Unknown model_family"):
C(base_model = "b", data_dir = "d", output_dir = "o", model_family = "not-a-family").normalized()
# A known-but-not-trainable family (Kontext editing) is rejected with a helpful hint.
with pytest.raises(ValueError):
C(base_model = "b", data_dir = "d", output_dir = "o", model_family = "flux.1-kontext").normalized()
# A DiT family that IS trainable resolves to itself.
assert (
C(base_model = "b", data_dir = "d", output_dir = "o", model_family = "flux.1")
.normalized()
.resolved_family
== "flux.1"
)
# SDXL explicit passes.
assert (
C(base_model = "b", data_dir = "d", output_dir = "o", model_family = "sdxl")
.normalized()
.resolved_family
== "sdxl"
)
def test_publish_writes_metadata_sidecar(tmp_path, monkeypatch):
import json as _json
from pathlib import Path
from core.inference import diffusion_lora
from core.training.diffusion_lora_trainer import _publish_to_lora_catalog
loras = tmp_path / "loras"
loras.mkdir()
monkeypatch.setattr(diffusion_lora, "loras_dir", lambda: loras)
src = tmp_path / "run" / "pytorch_lora_weights.safetensors"
src.parent.mkdir(parents = True)
src.write_bytes(b"fake-adapter")
cfg = DiffusionLoraConfig(
base_model = "stabilityai/sdxl-turbo",
data_dir = "d",
output_dir = str(tmp_path / "run"),
adapter_name = "my.style",
instance_prompt = "a photo in sks style",
lora_rank = 8,
).normalized()
dest = _publish_to_lora_catalog(str(src), cfg)
assert dest is not None
sidecar = Path(dest).with_suffix(".json")
assert sidecar.is_file()
meta = _json.loads(sidecar.read_text())
assert meta["family"] == "sdxl"
assert meta["families"] == ["sdxl"]
assert meta["base_model"] == "stabilityai/sdxl-turbo"
assert meta["lora_rank"] == 8
assert meta["trigger_prompt"] == "a photo in sks style"
assert meta["source"] == "studio-trained"