test_b2a_roundtrip failure in test_binascii.py

[colesbury]

Bug report

Bug description:

Seen in GitHub CI:

======================================================================
ERROR: test_b2a_roundtrip (test.test_binascii.BytearrayBinASCIITest.test_b2a_roundtrip)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython-ro-srcdir/Lib/test/test_binascii.py", line 233, in test_b2a_roundtrip
    binary=hypothesis.strategies.binary(),
           ^^^^^^^
  File "/home/runner/work/cpython/cpython-builddir/hypovenv/lib/python3.13/site-packages/hypothesis/core.py", line 1386, in wrapped_test
    raise the_error_hypothesis_found
  File "/home/runner/work/cpython/cpython-ro-srcdir/Lib/test/test_binascii.py", line 237, in test_b2a_roundtrip
    converted = binascii.b2a_uu(self.type2test(binary), backtick=backtick)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
binascii.Error: At most 45 bytes at once
Falsifying example: test_b2a_roundtrip(
    self=<test.test_binascii.BytearrayBinASCIITest testMethod=test_b2a_roundtrip>,
    binary=b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
    backtick=False,
)

You can reproduce this example by temporarily adding @reproduce_failure('6.84.0', b'AXicY2RgYBwciIEBAA2TAC8=') as a decorator on your test case

(https://github.com/python/cpython/actions/runs/6189137441/job/16802618181?pr=109344)

I think we need a max_size=45 in:

cpython/Lib/test/test_binascii.py

Lines 232 to 239 in 3b9d10b

	@hypothesis.given(
	binary=hypothesis.strategies.binary(),
	backtick=hypothesis.strategies.booleans(),
	)
	def test_b2a_roundtrip(self, binary, backtick):
	converted = binascii.b2a_uu(self.type2test(binary), backtick=backtick)
	restored = binascii.a2b_uu(self.type2test(converted))
	self.assertConversion(binary, converted, restored, backtick=backtick)

cc @sobolevn

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-109418: Fix hypothesis strategy for b2a_roundtrip test #109419

[hugovk]

This was added in #107863, cc @sobolevn.