[Python-checkins] gh-94808: Improve coverage of _PyBytes_FormatEx (GH-95895)

[miss-islington]

https://github.com/python/cpython/commit/295f510f5a789e356a11593dbefa9e9af615685c
commit: 295f510f5a789e356a11593dbefa9e9af615685c
branch: 3.11
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2022-09-07T05:18:33-07:00
summary:

gh-94808: Improve coverage of _PyBytes_FormatEx (GH-95895)


There were two specific areas not covered:

- %(name) syntax
- %*s syntax

Automerge-Triggered-By: GH:iritkatriel
(cherry picked from commit dde15f5879c3576db42ee4366fb684747c31459f)

Co-authored-by: Michael Droettboom <mdboom at gmail.com>

files:
M Lib/test/test_bytes.py

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 521e391b8d5..53ba1ad6f59 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -715,6 +715,24 @@ def test_mod(self):
         self.assertEqual(b, b'hello,\x00world!')
         self.assertIs(type(b), self.type2test)
 
+        def check(fmt, vals, result):
+            b = self.type2test(fmt)
+            b = b % vals
+            self.assertEqual(b, result)
+            self.assertIs(type(b), self.type2test)
+
+        # A set of tests adapted from test_unicode:UnicodeTest.test_formatting
+        check(b'...%(foo)b...', {b'foo':b"abc"}, b'...abc...')
+        check(b'...%(f(o)o)b...', {b'f(o)o':b"abc", b'foo':b'bar'}, b'...abc...')
+        check(b'...%(foo)b...', {b'foo':b"abc",b'def':123}, b'...abc...')
+        check(b'%*b', (5, b'abc',), b'  abc')
+        check(b'%*b', (-5, b'abc',), b'abc  ')
+        check(b'%*.*b', (5, 2, b'abc',), b'   ab')
+        check(b'%*.*b', (5, 3, b'abc',), b'  abc')
+        check(b'%i %*.*b', (10, 5, 3, b'abc',), b'10   abc')
+        check(b'%i%b %*.*b', (10, b'3', 5, 3, b'abc',), b'103   abc')
+        check(b'%c', b'a', b'a')
+
     def test_imod(self):
         b = self.type2test(b'hello, %b!')
         orig = b