[3.12] gh-131015: Add test for bytes formatting errors (#131881)

Lib/test/test_bytes.py

@@ -10,6 +10,7 @@
 import sys
 import copy
 import functools
+import operator
 import pickle
 import tempfile
 import textwrap
@@ -737,6 +738,37 @@ def check(fmt, vals, result):
         check(b'%i%b %*.*b', (10, b'3', 5, 3, b'abc',), b'103   abc')
         check(b'%c', b'a', b'a')
 
+        class PseudoFloat:
+            def __init__(self, value):
+                self.value = float(value)
+            def __int__(self):
+                return int(self.value)
+
+        pi = PseudoFloat(3.1415)
+
+        exceptions_params = [
+            ('%x format: an integer is required, not float', b'%x', 3.14),
+            ('%X format: an integer is required, not float', b'%X', 2.11),
+            ('%o format: an integer is required, not float', b'%o', 1.79),
+            ('%x format: an integer is required, not PseudoFloat', b'%x', pi),
+            ('%x format: an integer is required, not complex', b'%x', 3j),
+            ('%X format: an integer is required, not complex', b'%X', 2j),
+            ('%o format: an integer is required, not complex', b'%o', 1j),
+            ('%u format: a real number is required, not complex', b'%u', 3j),
+            # See https://github.com/python/cpython/issues/130928 as for why
+            # the exception message contains '%d' instead of '%i'.
+            ('%d format: a real number is required, not complex', b'%i', 2j),
+            ('%d format: a real number is required, not complex', b'%d', 2j),
+            (
+                r'%c requires an integer in range\(256\) or a single byte',
+                b'%c', pi
+            ),
+        ]
+
+        for msg, format_bytes, value in exceptions_params:
+            with self.assertRaisesRegex(TypeError, msg):
+                operator.mod(format_bytes, value)
+
     def test_imod(self):
         b = self.type2test(b'hello, %b!')
         orig = b