unsloth/studio/backend/tests/test_diffusion_dataset_api.py

626 lines
27 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
"""Tests for the diffusion dataset labeling + example-import routes.
The routes are hit with the FastAPI TestClient; the datasets root is redirected to a
tmp_path so nothing touches a real Studio home. The example importer is exercised with a
mocked datasets.load_dataset so no network / GPU is needed.
"""
from __future__ import annotations
import io
import json
import pytest
from fastapi import FastAPI, HTTPException
from fastapi.testclient import TestClient
from PIL import Image
from auth.authentication import get_current_subject
from routes.training import router as training_router
def _png_bytes(color = (200, 100, 50), size = (8, 8)) -> bytes:
buf = io.BytesIO()
Image.new("RGB", size, color).save(buf, format = "PNG")
return buf.getvalue()
def _write_png(
path,
color = (200, 100, 50),
size = (8, 8),
) -> None:
Image.new("RGB", size, color).save(path, format = "PNG")
@pytest.fixture
def client():
app = FastAPI()
app.include_router(training_router, prefix = "/api/train")
app.dependency_overrides[get_current_subject] = lambda: "test-user"
return TestClient(app)
@pytest.fixture
def ds_root(monkeypatch, tmp_path):
import utils.paths as up
root = tmp_path / "assets" / "datasets"
root.mkdir(parents = True)
monkeypatch.setattr(up, "datasets_root", lambda: root)
return root
# ── listing + caption precedence ─────────────────────────────────────────────
def test_list_images_caption_precedence(client, ds_root):
folder = ds_root / "styleset"
folder.mkdir()
_write_png(folder / "a.png")
_write_png(folder / "b.png")
_write_png(folder / "c.png")
# a.png -> sidecar (an explicit edit beats the metadata row), b.png -> metadata-only,
# c.png -> none.
(folder / "metadata.jsonl").write_text(
json.dumps({"file_name": "a.png", "text": "from metadata"})
+ "\n"
+ json.dumps({"file_name": "b.png", "text": "from metadata"})
+ "\n",
encoding = "utf-8",
)
(folder / "a.txt").write_text("edited sidecar", encoding = "utf-8")
r = client.get("/api/train/diffusion/dataset/styleset/images")
assert r.status_code == 200, r.text
body = r.json()
assert body["name"] == "styleset"
recs = {rec["filename"]: rec for rec in body["images"]}
assert set(recs) == {"a.png", "b.png", "c.png"}
# A sidecar edit overrides the metadata row for the same image.
assert recs["a.png"]["caption"] == "edited sidecar"
assert recs["a.png"]["caption_source"] == "sidecar"
assert recs["b.png"]["caption"] == "from metadata"
assert recs["b.png"]["caption_source"] == "metadata"
assert recs["c.png"]["caption"] is None
assert recs["c.png"]["caption_source"] == "none"
assert recs["a.png"]["width"] == 8 and recs["a.png"]["height"] == 8
def test_list_images_missing_dataset_404(client, ds_root):
assert client.get("/api/train/diffusion/dataset/nope/images").status_code == 404
# ── image serving + thumbnails ───────────────────────────────────────────────
def test_get_image_and_thumbnail_excluded_from_listing(client, ds_root):
folder = ds_root / "pics"
folder.mkdir()
_write_png(folder / "one.png", size = (64, 48))
full = client.get("/api/train/diffusion/dataset/pics/image/one.png")
assert full.status_code == 200, full.text
thumb = client.get("/api/train/diffusion/dataset/pics/image/one.png?thumb=32")
assert thumb.status_code == 200
assert thumb.headers["content-type"] == "image/jpeg"
assert (folder / ".thumbs").is_dir()
# The .thumbs cache dir must not surface as a dataset image.
listing = client.get("/api/train/diffusion/dataset/pics/images").json()
assert [rec["filename"] for rec in listing["images"]] == ["one.png"]
def test_get_image_missing_404(client, ds_root):
(ds_root / "pics").mkdir()
assert client.get("/api/train/diffusion/dataset/pics/image/ghost.png").status_code == 404
# ── caption write / clear ────────────────────────────────────────────────────
def test_put_caption_roundtrip_and_clear(client, ds_root):
folder = ds_root / "cap"
folder.mkdir()
_write_png(folder / "x.png")
r = client.put(
"/api/train/diffusion/dataset/cap/caption/x.png", json = {"caption": "a red apple"}
)
assert r.status_code == 200, r.text
assert r.json()["caption"] == "a red apple"
assert r.json()["caption_source"] == "sidecar"
assert (folder / "x.txt").read_text(encoding = "utf-8") == "a red apple"
# Blank clears the sidecar.
r = client.put("/api/train/diffusion/dataset/cap/caption/x.png", json = {"caption": " "})
assert r.status_code == 200
assert r.json()["caption"] is None
assert r.json()["caption_source"] == "none"
assert not (folder / "x.txt").exists()
def test_put_caption_overrides_metadata_row(client, ds_root):
# Editing a caption for an image that already has a metadata.jsonl row must take
# effect: the sidecar edit wins over the metadata caption in the response (and in
# the data the trainer reads), not the other way round.
folder = ds_root / "cap"
folder.mkdir()
_write_png(folder / "x.png")
(folder / "metadata.jsonl").write_text(
json.dumps({"file_name": "x.png", "text": "from metadata"}) + "\n", encoding = "utf-8"
)
r = client.put(
"/api/train/diffusion/dataset/cap/caption/x.png", json = {"caption": "edited caption"}
)
assert r.status_code == 200, r.text
assert r.json()["caption"] == "edited caption"
assert r.json()["caption_source"] == "sidecar"
def test_put_caption_missing_image_404(client, ds_root):
(ds_root / "cap").mkdir()
r = client.put("/api/train/diffusion/dataset/cap/caption/ghost.png", json = {"caption": "hi"})
assert r.status_code == 404
def test_put_caption_too_long_400(client, ds_root):
folder = ds_root / "cap"
folder.mkdir()
_write_png(folder / "x.png")
r = client.put("/api/train/diffusion/dataset/cap/caption/x.png", json = {"caption": "z" * 2001})
assert r.status_code == 400
# ── delete ───────────────────────────────────────────────────────────────────
def test_delete_image_cleans_sidecar_and_thumb(client, ds_root):
folder = ds_root / "d"
folder.mkdir()
_write_png(folder / "x.png")
(folder / "x.txt").write_text("cap", encoding = "utf-8")
# Generate a thumbnail so we can assert it is cleaned up too. Thumbs are keyed on
# the full filename (stem + extension) to avoid same-stem collisions across formats.
client.get("/api/train/diffusion/dataset/d/image/x.png?thumb=32")
assert list((folder / ".thumbs").glob("x.png_*.jpg"))
r = client.delete("/api/train/diffusion/dataset/d/image/x.png")
assert r.status_code == 200, r.text
assert not (folder / "x.png").exists()
assert not (folder / "x.txt").exists()
assert not list((folder / ".thumbs").glob("x.png_*.jpg"))
def test_thumb_cache_key_distinguishes_same_stem_extensions(client, ds_root):
# sample.png and sample.jpg share a stem; each must get its OWN thumbnail cache
# file, so the labeling grid never serves one image's thumbnail for the other.
folder = ds_root / "d"
folder.mkdir()
Image.new("RGB", (8, 8), (10, 20, 30)).save(folder / "sample.png", format = "PNG")
Image.new("RGB", (8, 8), (200, 210, 220)).save(folder / "sample.jpg", format = "JPEG")
client.get("/api/train/diffusion/dataset/d/image/sample.png?thumb=32")
client.get("/api/train/diffusion/dataset/d/image/sample.jpg?thumb=32")
thumbs = sorted(p.name for p in (folder / ".thumbs").glob("*.jpg"))
assert thumbs == ["sample.jpg_32.jpg", "sample.png_32.jpg"]
# ── traversal / validation ───────────────────────────────────────────────────
def test_dataset_name_traversal_rejected_over_http(client, ds_root):
# A name that fails the folder-name validator returns 400, never touches disk.
assert client.get("/api/train/diffusion/dataset/bad name!/images").status_code == 400
def test_image_filename_validation_rejects_traversal():
from pathlib import Path
from routes.training import _safe_dataset_image_path
folder = Path("/tmp/some-dataset")
for bad in ("../../etc/passwd", "/etc/passwd", "..", "sub/dir.png", "notimage.txt"):
with pytest.raises(HTTPException) as exc:
_safe_dataset_image_path(folder, bad)
assert exc.value.status_code == 400
# A plain image name resolves inside the folder.
assert _safe_dataset_image_path(folder, "ok.png") == folder / "ok.png"
def test_clean_dataset_name_rejects_dotdot():
from routes.training import _clean_diffusion_dataset_name
for bad in ("../x", "a/b", "..", " "):
with pytest.raises(HTTPException) as exc:
_clean_diffusion_dataset_name(bad)
assert exc.value.status_code == 400
# ── examples registry + import ───────────────────────────────────────────────
def test_list_dataset_examples(client, ds_root):
r = client.get("/api/train/diffusion/dataset-examples")
assert r.status_code == 200, r.text
ids = {e["id"] for e in r.json()["examples"]}
assert {
"dreambooth-dog",
"tuxemon",
"tarot-1920",
"smithsonian-butterflies",
"pixel-nouns",
} <= ids
dog = next(e for e in r.json()["examples"] if e["id"] == "dreambooth-dog")
assert dog["suggested_trigger"] == "a photo of sks dog"
assert dog["license"]
def test_list_dataset_examples_large_sets(client, ds_root):
# The two ~100-image sets: butterflies is a subject set (trigger, no caption column),
# nouns is a captioned style set (caption column, no trigger). Both cap at 100.
r = client.get("/api/train/diffusion/dataset-examples")
examples = {e["id"]: e for e in r.json()["examples"]}
butterflies = examples["smithsonian-butterflies"]
assert butterflies["image_cap"] == 100
assert butterflies["suggested_trigger"] == "a photo of a sks butterfly"
assert "CC0" in butterflies["license"]
nouns = examples["pixel-nouns"]
assert nouns["image_cap"] == 100
assert nouns["suggested_trigger"] is None
assert nouns["license"] == "cc0-1.0"
class _FakeImageFeature:
# Mimics datasets.Image so _detect_image_column matches by class name.
pass
_FakeImageFeature.__name__ = "Image"
class _FakeDS:
def __init__(self, rows, features):
self._rows = rows
self.features = features
def __iter__(self):
return iter(self._rows)
def _install_fake_load_dataset(monkeypatch, n_rows):
calls = {"count": 0}
rows = [
{"image": Image.new("RGB", (8, 8), (i * 30 % 255, 60, 90)), "prompt": f"caption {i}"}
for i in range(n_rows)
]
features = {"image": _FakeImageFeature(), "prompt": object()}
def fake_load(repo, **kwargs):
calls["count"] += 1
assert kwargs.get("split") == "train"
return _FakeDS(rows, features)
import datasets
monkeypatch.setattr(datasets, "load_dataset", fake_load)
return calls
def test_import_example_writes_images_and_captions(client, ds_root, monkeypatch):
calls = _install_fake_load_dataset(monkeypatch, n_rows = 3)
r = client.post(
"/api/train/diffusion/dataset/import-example",
json = {"id": "tuxemon", "name": "my-tux"},
)
assert r.status_code == 200, r.text
body = r.json()
assert body["name"] == "my-tux"
assert body["imported"] == 3
assert body["image_count"] == 3
assert body["caption_count"] == 3
assert body["license"] == "cc-by-sa-3.0"
assert body["source_repo"] == "linoyts/Tuxemon"
folder = ds_root / "my-tux"
assert sorted(p.name for p in folder.glob("*.png")) == [f"img_{i:04d}.png" for i in range(3)]
assert (folder / "img_0000.txt").read_text(encoding = "utf-8") == "caption 0"
# Idempotent: a second call does not reload or duplicate.
r2 = client.post(
"/api/train/diffusion/dataset/import-example",
json = {"id": "tuxemon", "name": "my-tux"},
)
assert r2.status_code == 200
assert r2.json()["imported"] == 0
assert r2.json()["image_count"] == 3
assert calls["count"] == 1
def test_import_example_respects_cap(client, ds_root, monkeypatch):
_install_fake_load_dataset(monkeypatch, n_rows = 5)
entry = next(
e
for e in __import__("routes.training", fromlist = ["_DATASET_EXAMPLES"])._DATASET_EXAMPLES
if e["id"] == "tuxemon"
)
monkeypatch.setitem(entry, "image_cap", 2)
r = client.post("/api/train/diffusion/dataset/import-example", json = {"id": "tuxemon"})
assert r.status_code == 200, r.text
assert r.json()["imported"] == 2
assert r.json()["image_count"] == 2
def test_import_example_unknown_id_404(client, ds_root):
r = client.post("/api/train/diffusion/dataset/import-example", json = {"id": "does-not-exist"})
assert r.status_code == 404
def test_import_example_load_failure_maps_to_502(client, ds_root, monkeypatch):
import datasets
def boom(repo, **kwargs):
raise RuntimeError("network down")
monkeypatch.setattr(datasets, "load_dataset", boom)
r = client.post("/api/train/diffusion/dataset/import-example", json = {"id": "tuxemon"})
assert r.status_code == 502
assert "Could not import" in r.json()["detail"]
# ── upload: same-stem image collision ────────────────────────────────────────
def _jpg_bytes(color = (30, 120, 200), size = (8, 8)) -> bytes:
buf = io.BytesIO()
Image.new("RGB", size, color).save(buf, format = "JPEG")
return buf.getvalue()
def _upload(client, name, files):
# files: list of (filename, bytes). Content type is irrelevant to the route (it keys off the
# extension), so send everything as octet-stream.
parts = [("files", (fn, data, "application/octet-stream")) for fn, data in files]
return client.post("/api/train/diffusion/dataset", data = {"name": name}, files = parts)
def test_upload_rejects_same_stem_different_extension(client, ds_root):
# sample.png and sample.jpg share the stem "sample", so both map to one sample.txt caption
# sidecar; keeping both would silently corrupt captions during training. The second must 400.
assert _upload(client, "styleset", [("sample.png", _png_bytes())]).status_code == 200
dup = _upload(client, "styleset", [("sample.jpg", _jpg_bytes())])
assert dup.status_code == 400
assert "Duplicate image name" in dup.json()["detail"]
# The rejected image never landed on disk: only sample.png survives.
folder = ds_root / "styleset"
assert sorted(p.name for p in folder.iterdir() if p.suffix != ".txt") == ["sample.png"]
def test_upload_same_stem_collision_within_one_batch(client, ds_root):
# The scan must cover files uploaded earlier IN THE SAME batch, not just those already on disk,
# so a single multipart request carrying both sample.png and sample.jpg is rejected too.
r = _upload(client, "styleset", [("sample.png", _png_bytes()), ("sample.jpg", _jpg_bytes())])
assert r.status_code == 400
assert "Duplicate image name" in r.json()["detail"]
def test_upload_rejects_exact_duplicate_name_within_one_batch(client, ds_root):
# Two parts with the SAME name in ONE multipart batch are distinct files (dragged from
# different folders, or an API client repeating a part); the staged commit would let the
# later tmp.replace(dest) silently discard the earlier one while `uploaded` still counts
# both. The batch must be rejected whole. Re-sending a name in a SEPARATE upload stays a
# deliberate overwrite (test_upload_allows_exact_name_overwrite_and_caption_sidecar).
r = _upload(
client,
"styleset",
[("sample.png", _png_bytes((10, 20, 30))), ("sample.png", _png_bytes((90, 90, 90)))],
)
assert r.status_code == 400
assert "more than once" in r.json()["detail"]
assert not (ds_root / "styleset" / "sample.png").exists() # all-or-nothing
# Caption files collide at one destination the same way.
r = _upload(client, "styleset", [("sample.txt", b"a"), ("sample.txt", b"b")])
assert r.status_code == 400
assert "more than once" in r.json()["detail"]
# A STEM case variant pair (Cat.png vs cat.png) stays exempt, matching the stem-guard
# contract: it is one file / an overwrite on case-insensitive filesystems, and on Linux
# the two files write separate sidecars (Cat.txt vs cat.txt) -- no caption collision.
r = _upload(client, "styleset", [("Cat.png", _png_bytes()), ("cat.png", _png_bytes())])
assert r.status_code == 200
def test_upload_rejects_extension_case_variant_sidecar_collision(client, ds_root):
# An EXTENSION-case variant pair (dog.PNG vs dog.png) has exactly equal stems: on a
# case-sensitive filesystem both files land and both resolve to ONE dog.txt caption
# sidecar, silently sharing/corrupting the caption. Must 400 both within one batch and
# against a file already on disk.
r = _upload(client, "styleset", [("dog.PNG", _png_bytes()), ("dog.png", _png_bytes())])
assert r.status_code == 400
assert "Duplicate image name" in r.json()["detail"]
folder = ds_root / "styleset"
assert not any(p.suffix.lower() == ".png" for p in folder.iterdir()) # all-or-nothing
assert _upload(client, "styleset", [("dog.png", _png_bytes())]).status_code == 200
dup = _upload(client, "styleset", [("dog.PNG", _png_bytes())])
assert dup.status_code == 400
assert "Duplicate image name" in dup.json()["detail"]
assert sorted(p.name for p in folder.iterdir() if p.suffix != ".txt") == ["dog.png"]
def test_upload_allows_exact_name_overwrite_and_caption_sidecar(client, ds_root):
# Re-uploading the EXACT same name (stem AND extension) is an allowed overwrite, and a .txt
# caption for the same stem is the intended kohya flow -- neither is a same-stem image collision.
assert (
_upload(client, "styleset", [("sample.png", _png_bytes((10, 20, 30)))]).status_code == 200
)
assert (
_upload(client, "styleset", [("sample.png", _png_bytes((90, 90, 90)))]).status_code == 200
)
assert _upload(client, "styleset", [("sample.txt", b"a caption")]).status_code == 200
folder = ds_root / "styleset"
assert (folder / "sample.png").is_file()
assert (folder / "sample.txt").read_text(encoding = "utf-8") == "a caption"
# ── import: promotion is all-or-nothing ──────────────────────────────────────
def test_import_promotion_leaves_no_partial_dataset_on_failure(ds_root, monkeypatch):
# The staging dir is promoted into the dataset folder in one atomic rename. If that rename
# fails (a crash / filesystem error mid-promotion), the folder must be left with NO images
# rather than a half-filled dataset that the image_count>0 idempotency check would then accept
# as complete on retry -- stranding the user with a truncated dataset. Simulate the promotion
# rename failing, assert nothing partial is left, and assert a retry re-imports cleanly.
import os
# A client that returns the 500 (as production does) instead of re-raising the server exception.
app = FastAPI()
app.include_router(training_router, prefix = "/api/train")
app.dependency_overrides[get_current_subject] = lambda: "test-user"
noraise = TestClient(app, raise_server_exceptions = False)
calls = _install_fake_load_dataset(monkeypatch, n_rows = 3)
folder = ds_root / "my-tux"
real_replace = os.replace
def flaky_replace(src, dst, *a, **k):
# Only sabotage the staging -> folder promotion; leave every other rename working.
if str(dst) == str(folder):
raise OSError("simulated crash during promotion")
return real_replace(src, dst, *a, **k)
monkeypatch.setattr(os, "replace", flaky_replace)
r = noraise.post(
"/api/train/diffusion/dataset/import-example",
json = {"id": "tuxemon", "name": "my-tux"},
)
assert r.status_code == 500
# No half-filled dataset: the folder holds zero images (and no stray staging dir lingers).
assert list(ds_root.glob("my-tux/*.png")) == []
assert not any(p.name.startswith(".my-tux.import-") for p in ds_root.iterdir())
# Retry with the promotion working: a clean, complete import (idempotency did not short-circuit).
monkeypatch.setattr(os, "replace", real_replace)
r2 = noraise.post(
"/api/train/diffusion/dataset/import-example",
json = {"id": "tuxemon", "name": "my-tux"},
)
assert r2.status_code == 200, r2.text
assert r2.json()["imported"] == 3
assert calls["count"] == 2 # the failed attempt did not leave a dataset that blocks a reload
def test_upload_rolls_back_when_a_later_promotion_fails(ds_root, monkeypatch):
# Re-uploading a.txt and b.txt where the SECOND commit fails must roll back the first overwrite,
# so both originals survive and no stray temp/backup files remain.
from pathlib import Path
app = FastAPI()
app.include_router(training_router, prefix = "/api/train")
app.dependency_overrides[get_current_subject] = lambda: "test-user"
noraise = TestClient(app, raise_server_exceptions = False)
folder = ds_root / "styleset"
folder.mkdir()
(folder / "a.txt").write_bytes(b"ORIGINAL-A")
(folder / "b.txt").write_bytes(b"ORIGINAL-B")
real_replace = Path.replace
state = {"failed": False}
def flaky_replace(self, target, *a, **k):
# Fail once on the tmp -> b.txt promotion only (not the backup restore), so rollback works.
if (
not state["failed"]
and str(target).endswith("b.txt")
and self.name.startswith(".upload-")
and not self.name.startswith(".upload-backup-")
):
state["failed"] = True
raise OSError("simulated second commit failure")
return real_replace(self, target, *a, **k)
monkeypatch.setattr(Path, "replace", flaky_replace)
parts = [
("files", ("a.txt", b"NEW-A", "application/octet-stream")),
("files", ("b.txt", b"NEW-B", "application/octet-stream")),
]
r = noraise.post("/api/train/diffusion/dataset", data = {"name": "styleset"}, files = parts)
assert r.status_code == 500
monkeypatch.setattr(Path, "replace", real_replace)
# Both originals are intact -- no partial overwrite of the live dataset.
assert (folder / "a.txt").read_bytes() == b"ORIGINAL-A"
assert (folder / "b.txt").read_bytes() == b"ORIGINAL-B"
# No staging or backup artifacts left behind.
assert not list(folder.glob(".upload-*.part"))
assert not list(folder.glob(".upload-backup-*.part"))
def test_resolve_dataset_folder_rejects_symlink(ds_root, tmp_path):
# A dataset dir that is a symlink outside the datasets root must be rejected, else delete /
# caption / read could operate on external files through the link.
from routes.training import _resolve_dataset_folder
external = tmp_path / "external"
external.mkdir()
(external / "victim.png").write_bytes(_png_bytes())
(ds_root / "linked").symlink_to(external, target_is_directory = True)
with pytest.raises(HTTPException) as exc:
_resolve_dataset_folder("linked")
assert exc.value.status_code == 400
def test_upload_through_symlinked_dataset_cannot_escape_root(client, ds_root, tmp_path):
# An upload to a dataset name that is a symlink to an external directory must be refused (400)
# before any bytes are written.
external = tmp_path / "external"
external.mkdir()
(ds_root / "linked").symlink_to(external, target_is_directory = True)
r = _upload(client, "linked", [("intruder.png", _png_bytes())])
assert r.status_code == 400
assert "symbolic link" in r.json()["detail"]
# Nothing was written through the link into the external directory.
assert not (external / "intruder.png").exists()
assert not any(external.iterdir())
def test_delete_through_symlinked_dataset_cannot_escape_root(client, ds_root, tmp_path):
# A DELETE inside a symlinked dataset dir is refused (400) and the external file survives.
external = tmp_path / "external"
external.mkdir()
victim = external / "victim.png"
_write_png(victim)
(ds_root / "linked").symlink_to(external, target_is_directory = True)
r = client.delete("/api/train/diffusion/dataset/linked/image/victim.png")
assert r.status_code == 400
assert victim.exists() # the external file survives
def test_delete_image_with_glob_chars_only_removes_own_thumbs(client, ds_root):
# Deleting a filename with glob metacharacters (e.g. "[ab].png") must remove only its own
# thumbnails, not a sibling's that the raw glob would spuriously match.
from urllib.parse import quote
folder = ds_root / "d"
folder.mkdir()
_write_png(folder / "[ab].png")
_write_png(folder / "a.png")
thumbs = folder / ".thumbs"
thumbs.mkdir()
(thumbs / "[ab].png_32.jpg").write_bytes(b"own")
(thumbs / "a.png_32.jpg").write_bytes(b"sibling")
r = client.delete("/api/train/diffusion/dataset/d/image/" + quote("[ab].png", safe = ""))
assert r.status_code == 200, r.text
# Its own thumbnail is gone; the sibling a.png's thumbnail is untouched.
assert not (thumbs / "[ab].png_32.jpg").exists()
assert (thumbs / "a.png_32.jpg").exists()
assert not (folder / "[ab].png").exists()
assert (folder / "a.png").exists()
def test_import_preserves_unrelated_files_when_folder_not_empty(client, ds_root, monkeypatch):
# If the target folder already holds unrelated NON-image files (so image_count is still 0 and
# the import runs), the atomic rmdir refuses and the code falls back to a per-file move: the
# images are imported AND the pre-existing file is preserved rather than clobbered or lost.
_install_fake_load_dataset(monkeypatch, n_rows = 3)
folder = ds_root / "my-tux"
folder.mkdir(parents = True)
(folder / "notes.md").write_text("keep me", encoding = "utf-8")
r = client.post(
"/api/train/diffusion/dataset/import-example",
json = {"id": "tuxemon", "name": "my-tux"},
)
assert r.status_code == 200, r.text
assert r.json()["imported"] == 3
assert sorted(p.name for p in folder.glob("*.png")) == [f"img_{i:04d}.png" for i in range(3)]
assert (folder / "notes.md").read_text(encoding = "utf-8") == "keep me"