Files
libretro/tests/test_resolution_evidence.py
T

251 lines
8.2 KiB
Python

#!/usr/bin/env python3
"""Judging a candidate that was found by its name.
A file reached through a directory walk was matched on its filename, which is
the weakest evidence the resolver has: kanji.rom names a font inside a paid
Android package, an openMSX font and a 3DO ROM. Whatever the entry declares
about content is checked before such a candidate may be returned, and this
predicate is that check.
"""
from __future__ import annotations
import hashlib
import sys
import tempfile
import unittest
import zipfile
import zlib
from pathlib import Path
REPO_ROOT = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(REPO_ROOT / "scripts"))
import common # noqa: E402
PAYLOAD = b"THE BYTES THE ENTRY MEANS"
OTHER = b"A DIFFERENT FILE ANSWERING TO THE SAME NAME"
def digests(blob: bytes) -> dict:
return {
"sha1": hashlib.sha1(blob).hexdigest(),
"sha256": hashlib.sha256(blob).hexdigest(),
"md5": hashlib.md5(blob).hexdigest(),
"crc32": format(zlib.crc32(blob) & 0xFFFFFFFF, "08x"),
}
class DeclaredHashVerdict(unittest.TestCase):
def setUp(self):
self._tmp = tempfile.TemporaryDirectory()
root = Path(self._tmp.name)
self.right = root / "right.bin"
self.right.write_bytes(PAYLOAD)
self.wrong = root / "wrong.bin"
self.wrong.write_bytes(OTHER)
self.d = digests(PAYLOAD)
def tearDown(self):
self._tmp.cleanup()
def verdict(self, path, **declared):
base = dict(
has_strong_hash=True, sha1_candidates=set(), sha256_candidates=set(),
md5_list=[], crc_raw="", zipped_file=None, declared_size=None,
)
base.update(declared)
return common.declared_hash_verdict(str(path), **base)
def test_no_declared_hash_means_the_name_is_all_there_is(self):
self.assertEqual(
self.verdict(self.right, has_strong_hash=False), "data_dir"
)
def test_a_matching_sha1_confirms_the_candidate(self):
self.assertEqual(
self.verdict(self.right, sha1_candidates={self.d["sha1"]}),
"data_dir_hash_exact",
)
def test_a_contradicted_sha1_rejects_it(self):
self.assertEqual(
self.verdict(self.wrong, sha1_candidates={self.d["sha1"]}),
"hash_mismatch",
)
def test_sha256_is_checked(self):
self.assertEqual(
self.verdict(self.wrong, sha256_candidates={self.d["sha256"]}),
"hash_mismatch",
)
def test_crc32_is_checked(self):
self.assertEqual(
self.verdict(self.wrong, crc_raw=self.d["crc32"]), "hash_mismatch"
)
def test_a_truncated_md5_still_decides(self):
"""Batocera publishes 29-character prefixes, which are still evidence."""
self.assertEqual(
self.verdict(self.right, md5_list=[self.d["md5"][:29]]),
"data_dir_hash_exact",
)
self.assertEqual(
self.verdict(self.wrong, md5_list=[self.d["md5"][:29]]),
"hash_mismatch",
)
def test_every_declaration_has_to_hold(self):
"""One satisfied hash does not excuse another that is contradicted."""
self.assertEqual(
self.verdict(
self.right,
sha1_candidates={self.d["sha1"]},
crc_raw="deadbeef",
),
"hash_mismatch",
)
def test_a_size_beside_a_crc32_is_enforced(self):
self.assertEqual(
self.verdict(
self.right, crc_raw=self.d["crc32"], declared_size=len(PAYLOAD)
),
"data_dir_hash_exact",
)
self.assertEqual(
self.verdict(
self.right, crc_raw=self.d["crc32"], declared_size=len(PAYLOAD) + 1
),
"hash_mismatch",
)
def test_a_list_of_allowed_sizes_is_accepted(self):
self.assertEqual(
self.verdict(
self.right,
crc_raw=self.d["crc32"],
declared_size=[1, len(PAYLOAD)],
),
"data_dir_hash_exact",
)
def test_a_zipped_member_is_checked_inside_the_archive(self):
"""With zipped_file the md5 describes a ROM, not the container."""
archive = Path(self._tmp.name) / "set.zip"
with zipfile.ZipFile(archive, "w") as zf:
zf.writestr("rom.bin", PAYLOAD)
self.assertEqual(
self.verdict(
archive, md5_list=[self.d["md5"]], zipped_file="rom.bin"
),
"data_dir_hash_exact",
)
self.assertEqual(
self.verdict(
archive, md5_list=[digests(OTHER)["md5"]], zipped_file="rom.bin"
),
"hash_mismatch",
)
class AgnosticFallback(unittest.TestCase):
"""Cores that accept any filename identify a file by its shape alone."""
def setUp(self):
self._tmp = tempfile.TemporaryDirectory()
self.root = Path(self._tmp.name)
self.match = self.root / "anything.bin"
self.match.write_bytes(b"x" * 64)
self.files_db = {
"a": {"path": str(self.match), "size": 64},
"b": {"path": str(self.root / "absent.bin"), "size": 64},
}
def tearDown(self):
self._tmp.cleanup()
def test_a_file_of_the_declared_size_under_the_prefix_answers(self):
entry = {
"agnostic": True,
"agnostic_path_prefix": str(self.root),
"size": 64,
}
self.assertEqual(
common._resolve_agnostic(entry, self.files_db, False),
(str(self.match), "agnostic_fallback"),
)
def test_a_declared_hash_outranks_the_shape(self):
entry = {"agnostic": True, "agnostic_path_prefix": str(self.root), "size": 64}
self.assertIsNone(common._resolve_agnostic(entry, self.files_db, True))
def test_the_wrong_size_is_not_a_candidate(self):
entry = {
"agnostic": True,
"agnostic_path_prefix": str(self.root),
"size": 65,
}
self.assertIsNone(common._resolve_agnostic(entry, self.files_db, False))
def test_a_size_range_is_honoured(self):
entry = {
"agnostic": True,
"agnostic_path_prefix": str(self.root),
"min_size": 32,
"max_size": 128,
}
self.assertIsNotNone(common._resolve_agnostic(entry, self.files_db, False))
def test_a_list_of_accepted_sizes_is_honoured(self):
entry = {
"agnostic": True,
"agnostic_path_prefix": str(self.root),
"size": [32, 64],
}
self.assertEqual(
common._resolve_agnostic(entry, self.files_db, False),
(str(self.match), "agnostic_fallback"),
)
entry["size"] = [32, 65]
self.assertIsNone(common._resolve_agnostic(entry, self.files_db, False))
def test_without_a_prefix_nothing_is_scanned(self):
entry = {"agnostic": True, "size": 64}
self.assertIsNone(common._resolve_agnostic(entry, self.files_db, False))
def test_an_entry_that_is_not_agnostic_is_left_alone(self):
entry = {"agnostic_path_prefix": str(self.root), "size": 64}
self.assertIsNone(common._resolve_agnostic(entry, self.files_db, False))
class OneSpellingForAcceptedSizes(unittest.TestCase):
"""A set of sizes the code accepts is ``size: [a, b]`` and nothing else.
SC-55/ROM2.BIN declared its two sizes under a field the resolver never
read and resolved by name to a PlayStation 2 ROM of a third size.
"""
def test_no_profile_uses_a_second_field(self):
offenders = [
path.name
for path in sorted((REPO_ROOT / "emulators").glob("*.yml"))
if "size_options" in path.read_text(encoding="utf-8")
]
self.assertEqual(offenders, [])
def test_the_schema_refuses_the_second_field(self):
import json
schema = json.loads(
(REPO_ROOT / "schemas/emulator.schema.json").read_text(encoding="utf-8")
)
file_entry = schema["properties"]["files"]["items"]["properties"]
self.assertNotIn("size_options", file_entry)
self.assertEqual(file_entry["size"]["type"], ["integer", "array", "null"])
if __name__ == "__main__":
unittest.main()