chore: drop files whose bytes are not what they claim

tests/test_identity.py

@@ -0,0 +1,103 @@
+"""One content, several identities: which crossings are a misfiling."""
+
+from __future__ import annotations
+
+import shutil
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "scripts"))
+
+import identity  # noqa: E402
+
+
+class TestCrossVendorDuplicates(unittest.TestCase):
+    """A dump answering to two makers is a finding until it is explained."""
+
+    def setUp(self):
+        self.root = Path(tempfile.mkdtemp(prefix="identity-"))
+
+    def tearDown(self):
+        shutil.rmtree(self.root, ignore_errors=True)
+
+    def _write(self, relative: str, payload: bytes) -> None:
+        path = self.root / "bios" / relative
+        path.parent.mkdir(parents=True, exist_ok=True)
+        path.write_bytes(payload)
+
+    def _scan(self):
+        return identity.scan(str(self.root / "bios"))
+
+    def test_one_dump_under_two_makers_is_reported(self):
+        self._write("Commodore/Amiga/kickstart.rom", b"kick")
+        self._write("Sega/Saturn/cartridge.bin", b"kick")
+        found = self._scan()
+        self.assertEqual(len(found), 1)
+        self.assertEqual(found[0].manufacturers, ["Commodore", "Sega"])
+        self.assertEqual(found[0].names, ["cartridge.bin", "kickstart.rom"])
+
+    def test_two_copies_under_one_maker_are_not_a_finding(self):
+        self._write("Sinclair/ZX Spectrum/48.rom", b"rom")
+        self._write("Sinclair/ZX Spectrum/spectrum48.rom", b"rom")
+        self.assertEqual(self._scan(), [])
+
+    def test_the_same_name_twice_is_a_copy_not_a_contradiction(self):
+        self._write("Coleco/ColecoVision/coleco.rom", b"rom")
+        self._write("Microsoft/MSX/coleco.rom", b"rom")
+        self.assertEqual(self._scan(), [])
+
+    def test_shared_trees_do_not_count_as_a_maker(self):
+        # Arcade and Other hold files belonging to many machines by design.
+        self._write("Arcade/FBNeo/spectrum.rom", b"rom")
+        self._write("Sinclair/ZX Spectrum/48.rom", b"rom")
+        self.assertEqual(self._scan(), [])
+
+    def test_an_explained_crossing_is_silent(self):
+        self._write("Magnavox/Odyssey2/o2rom.bin", b"odyssey")
+        self._write("Philips/Videopac/O2.bin", b"odyssey")
+        first = self._scan()
+        self.assertEqual(len(first), 1)
+        identity.KNOWN_SHARED[first[0].sha1] = "one machine, two market names"
+        try:
+            self.assertEqual(self._scan(), [])
+        finally:
+            del identity.KNOWN_SHARED[first[0].sha1]
+
+    def test_distinct_contents_are_never_grouped(self):
+        self._write("Commodore/Amiga/kickstart.rom", b"kick")
+        self._write("Sega/Saturn/cartridge.bin", b"other")
+        self.assertEqual(self._scan(), [])
+
+    def test_report_line_names_every_identity(self):
+        self._write("Commodore/Amiga/kickstart.rom", b"kick")
+        self._write("Sega/Saturn/cartridge.bin", b"kick")
+        line = identity.format_duplicate(self._scan()[0])
+        self.assertIn("kickstart.rom", line)
+        self.assertIn("cartridge.bin", line)
+
+
+class TestAllowList(unittest.TestCase):
+    """Every exemption carries the reason it is one."""
+
+    def test_each_entry_is_a_full_sha1_with_a_reason(self):
+        for sha1, reason in identity.KNOWN_SHARED.items():
+            self.assertEqual(len(sha1), 40, sha1)
+            self.assertTrue(all(c in "0123456789abcdef" for c in sha1), sha1)
+            self.assertGreater(len(reason), 20, sha1)
+
+    def test_the_repository_has_no_unexplained_crossing(self):
+        repo = Path(__file__).resolve().parents[1] / "bios"
+        if not repo.is_dir():
+            self.skipTest("bios/ not present")
+        found = identity.scan(str(repo))
+        self.assertEqual(
+            [identity.format_duplicate(d) for d in found],
+            [],
+            "explain the crossing in KNOWN_SHARED, or the file is misfiled",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()