pythongh-96954: Add tests for unicodedata.name/lookup (python#96955)

They were undertested, and since python#96954 might involve a rewrite of this part of the code we want to ensure that there won't be any behavioral change. Co-authored-by: Carl Friedrich Bolz-Tereick <cfbolz@gmx.de>

Author: isidentical

Lib/test/test_unicodedata.py

@@ -71,7 +71,7 @@ class UnicodeFunctionsTest(UnicodeDatabaseTest):
 
  # Update this if the database changes. Make sure to do a full rebuild
  # (e.g. 'make distclean && make') to get the correct checksum.
- expectedchecksum = '84b88a89f40aeae96852732f9dc0ee08be49780f'
+ expectedchecksum = '26ff0d31c14194b4606a5b3a81ac36df3a14e331'
 
  @requires_resource('cpu')
  def test_function_checksum(self):
@@ -91,11 +91,19 @@ def test_function_checksum(self):
  str(self.db.mirrored(char)),
  str(self.db.combining(char)),
  unicodedata.east_asian_width(char),
+ self.db.name(char, ""),
  ]
  h.update(''.join(data).encode("ascii"))
  result = h.hexdigest()
  self.assertEqual(result, self.expectedchecksum)
 
+ @requires_resource('cpu')
+ def test_name_inverse_lookup(self):
+ for i in range(sys.maxunicode + 1):
+ char = chr(i)
+ if looked_name := self.db.name(char, None):
+ self.assertEqual(self.db.lookup(looked_name), char)
+
  def test_digit(self):
  self.assertEqual(self.db.digit('A', None), None)
  self.assertEqual(self.db.digit('9'), 9)