gh-124295: Add translation tests for argparse (GH-124803)

Lib/test/test_argparse.py

@@ -7,8 +7,10 @@
 import operator
 import os
 import py_compile
+import re
 import shutil
 import stat
+import subprocess
 import sys
 import textwrap
 import tempfile
@@ -17,9 +19,13 @@
 import warnings
 
 from enum import StrEnum
+from pathlib import Path
+from test.support import REPO_ROOT
+from test.support import TEST_HOME_DIR
 from test.support import captured_stderr
 from test.support import import_helper
 from test.support import os_helper
+from test.support import requires_subprocess
 from test.support import script_helper
 from unittest import mock
 
@@ -7014,6 +7020,54 @@ def test_directory_in_zipfile(self, compiled=False):
     def test_directory_in_zipfile_compiled(self):
         self.test_directory_in_zipfile(compiled=True)
 
+# =================
+# Translation tests
+# =================
+
+pygettext = Path(REPO_ROOT) / 'Tools' / 'i18n' / 'pygettext.py'
+snapshot_path = Path(TEST_HOME_DIR) / 'translationdata' / 'argparse' / 'msgids.txt'
+
+msgid_pattern = re.compile(r'msgid(.*?)(?:msgid_plural|msgctxt|msgstr)', re.DOTALL)
+msgid_string_pattern = re.compile(r'"((?:\\"|[^"])*)"')
+
+
+@requires_subprocess()
+class TestTranslations(unittest.TestCase):
+
+    def test_translations(self):
+        # Test messages extracted from the argparse module against a snapshot
+        res = generate_po_file(stdout_only=False)
+        self.assertEqual(res.returncode, 0)
+        self.assertEqual(res.stderr, '')
+        msgids = extract_msgids(res.stdout)
+        snapshot = snapshot_path.read_text().splitlines()
+        self.assertListEqual(msgids, snapshot)
+
+
+def generate_po_file(*, stdout_only=True):
+    res = subprocess.run([sys.executable, pygettext,
+                          '--no-location', '-o', '-', argparse.__file__],
+                         stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
+    if stdout_only:
+        return res.stdout
+    return res
+
+
+def extract_msgids(po):
+    msgids = []
+    for msgid in msgid_pattern.findall(po):
+        msgid_string = ''.join(msgid_string_pattern.findall(msgid))
+        msgid_string = msgid_string.replace(r'\"', '"')
+        if msgid_string:
+            msgids.append(msgid_string)
+    return sorted(msgids)
+
+
+def update_translation_snapshots():
+    contents = generate_po_file()
+    msgids = extract_msgids(contents)
+    snapshot_path.write_text('\n'.join(msgids))
+
 
 def tearDownModule():
     # Remove global references to avoid looking like we have refleaks.
@@ -7022,4 +7076,8 @@ def tearDownModule():
 
 
 if __name__ == '__main__':
+    # To regenerate translation snapshots
+    if len(sys.argv) > 1 and sys.argv[1] == '--snapshot-update':
+        update_translation_snapshots()
+        sys.exit(0)
     unittest.main()

Lib/test/translationdata/argparse/msgids.txt

@@ -0,0 +1,41 @@
+ (default: %(default)s)
+%(heading)s:
+%(prog)s: error: %(message)s\n
+%(prog)s: warning: %(message)s\n
+%r is not callable
+'required' is an invalid argument for positionals
+.__call__() not defined
+ambiguous option: %(option)s could match %(matches)s
+argument "-" with mode %r
+argument %(argument_name)s: %(message)s
+argument '%(argument_name)s' is deprecated
+can't open '%(filename)s': %(error)s
+cannot have multiple subparser arguments
+cannot merge actions - two groups are named %r
+command '%(parser_name)s' is deprecated
+conflicting subparser alias: %s
+conflicting subparser: %s
+dest= is required for options like %r
+expected at least one argument
+expected at most one argument
+expected one argument
+ignored explicit argument %r
+invalid %(type)s value: %(value)r
+invalid choice: %(value)r (choose from %(choices)s)
+invalid choice: %(value)r, maybe you meant %(closest)r? (choose from %(choices)s)
+invalid conflict_resolution value: %r
+invalid option string %(option)r: must start with a character %(prefix_chars)r
+mutually exclusive arguments must be optional
+not allowed with argument %s
+one of the arguments %s is required
+option '%(option)s' is deprecated
+options
+positional arguments
+show program's version number and exit
+show this help message and exit
+subcommands
+the following arguments are required: %s
+unexpected option string: %s
+unknown parser %(parser_name)r (choices: %(choices)s)
+unrecognized arguments: %s
+usage: 

Makefile.pre.in

@@ -2548,6 +2548,8 @@ TESTSUBDIRS=	idlelib/idle_test \
 		test/tkinterdata \
 		test/tokenizedata \
 		test/tracedmodules \
+		test/translationdata \
+		test/translationdata/argparse \
 		test/typinganndata \
 		test/wheeldata \
 		test/xmltestdata \

Misc/NEWS.d/next/Tests/2024-09-30-22-52-44.gh-issue-124295.VZy5kx.rst

@@ -0,0 +1 @@
+Add translation tests to the :mod:`argparse` module.