create a more simple validate function, fix test to be more complete

ui/medashare/btv/__init__.py

@@ -13,7 +13,7 @@ import unittest
 
 _encoding = 'utf-8'
 
-__all__ = [ 'validate' ]
+__all__ = [ 'validate', 'validate_file' ]
 
 class Storage:
 	'''A class to help read pieces of a torrent.
@@ -117,6 +117,18 @@ class Storage:
 				fp.seek(i['offset'])
 				fun(fp.read(i['size']))
 
+def validate_file(fname):
+	fname = pathlib.Path(fname)
+
+	with open(fname, 'rb') as fp:
+		torrent = bencode.bdecode(fp.read())
+
+	dirname = list(fname.parent.rglob(torrent['info']['name'].decode(_encoding)))[0]
+
+	tordir = dirname.parent
+
+	return validate(torrent, tordir)
+
 def validate(torrent, basedir):
 	'''Take a decode torrent file, where it was stored in basedir,
 	verify the torrent.  Returns a pair of set, the first is all the
@@ -175,13 +187,13 @@ class _TestCases(unittest.TestCase):
 	def setUp(self):
 		d = pathlib.Path(tempfile.mkdtemp()).resolve()
 
+		self.basetempdir = d
+
 		tor = importlib.resources.files(__name__)
 		tor = tor / 'fixtures' / 'somedir.torrent'
 		with tor.open('rb') as fp:
 			self.torrent = bencode.bdecode(fp.read())
 
-		self.basetempdir = d
-
 		self.oldcwd = os.getcwd()
 
 		os.chdir(d)
@@ -201,12 +213,19 @@ class _TestCases(unittest.TestCase):
 				fp.write(v)
 
 	def test_completeverif(self):
-		sd = self.basetempdir / self.dirname
+		tf = self.basetempdir / 'a.torrent'
+		with open(tf, 'wb') as fp:
+			fp.write(bencode.bencode(self.torrent))
+
+		sd = self.basetempdir / 'anotherdir' / self.dirname
+		sd.parent.mkdir()
 		sd.mkdir()
 
 		self.make_files(sd, self.origfiledata)
 
-		validate(self.torrent, self.basetempdir)
+		good, bad = validate_file(tf)
+
+		self.assertFalse(bad)
 
 		# that utf-8 encoded names work
 
@@ -221,7 +240,9 @@ class _TestCases(unittest.TestCase):
 		with tor.open('rb') as fp:
 			torrent = bencode.bdecode(fp.read())
 
-		validate(torrent, self.basetempdir)
+		good, bad = validate(torrent, self.basetempdir)
+
+		self.assertFalse(bad)
 
 	def test_verification(self):
 		# Testing for "missing" files