feat(checks): add accelerator key consistency check

docs/changes.rst

@@ -5,6 +5,8 @@ Weblate 2026.7
 
 .. rubric:: New features
 
+* Added the :ref:`check-accelerators` quality check, which verifies that accelerator keys are used consistently between the source and the translation. Enable it with the ``accelerators`` flag.
+
 .. rubric:: Improvements
 
 * Management interface access control is now more fine-grained with dedicated site-wide permissions.

docs/snippets/check-flags-autogenerated.rst

@@ -47,6 +47,8 @@
 .. AUTOGENERATED START: check-flags-enables
 .. This section is automatically generated by `./manage.py list_checks`. Do not edit manually.
 
+``accelerators``
+    Enables the :ref:`check-accelerators` quality check.
 ``bbcode-text``
     Treat a text as an Bulletin Board Code (BBCode) document, affects :ref:`check-same`.
     Enables the :ref:`check-bbcode` quality check.
@@ -150,6 +152,8 @@
 .. AUTOGENERATED START: check-flags-ignores
 .. This section is automatically generated by `./manage.py list_checks`. Do not edit manually.
 
+``ignore-accelerators``
+    Skip the :ref:`check-accelerators` quality check.
 ``ignore-bbcode``
     Skip the :ref:`check-bbcode` quality check.
 ``ignore-xml-chars-around-tags``

docs/snippets/checks-autogenerated.rst

@@ -4,6 +4,38 @@ Translation checks
 Executed upon every translation change, helping translators maintain
 good quality translations.
 
+.. AUTOGENERATED START: check-accelerators
+.. This section is automatically generated by `./manage.py list_checks`. Do not edit manually.
+
+.. _check-accelerators:
+
+Accelerator key
+~~~~~~~~~~~~~~~
+
+.. versionadded:: 2026.7
+
+:Summary: Source and translation do not both contain an accelerator key.
+:Scope: translated strings
+:Check class: ``weblate.checks.chars.AcceleratorKeyCheck``
+:Check identifier: ``accelerators``
+:Trigger: This check needs to be enabled using a flag.
+:Flag to enable: ``accelerators``
+:Flag to ignore: ``ignore-accelerators``
+
+.. AUTOGENERATED END: check-accelerators
+
+Accelerator keys (also known as mnemonics) let users trigger a UI action from
+the keyboard. They are marked in the string by a single character, typically
+``&`` (Qt, Windows) or ``_`` (GTK). This check verifies that the source and the
+translation contain the same number of accelerator keys, and that the
+translation does not contain more than one.
+
+.. note::
+
+    A string such as ``Walter & Sons`` might be translated without the
+    ampersand and trigger a false positive. Use the ``ignore-accelerators``
+    flag to skip the check for such strings.
+
 .. AUTOGENERATED START: check-bbcode
 .. This section is automatically generated by `./manage.py list_checks`. Do not edit manually.
 

weblate/checks/chars.py

@@ -41,6 +41,26 @@
 INTERROBANGS = ("?!", "!?", "؟!", "!؟", "？！", "！？", "⁈", "⁉")
 
 
+class AcceleratorKeyCheck(TargetCheck):
+    """Check for inconsistent accelerator keys."""
+
+    check_id = "accelerators"
+    name = gettext_lazy("Accelerator key")
+    description = gettext_lazy(
+        "Source and translation do not both contain an accelerator key."
+    )
+    default_disabled = True
+    version_added = "2026.7"
+
+    def _check_accelerator(self, source: str, target: str, key: str) -> bool:
+        return target.count(key) > 1 or source.count(key) != target.count(key)
+
+    def check_single(self, source: str, target: str, unit: Unit):
+        return self._check_accelerator(source, target, "&") or self._check_accelerator(
+            source, target, "_"
+        )
+
+
 class BeginNewlineCheck(TargetCheck):
     """Check for newlines at beginning."""
 
@@ -553,7 +573,7 @@
         )
         for i, char in enumerate(target):
             # Advance to the next highlighted range if we've passed the current one.
             while current_start is not None and i >= current_end:
                 range_index += 1
                 if range_index < len(highlighted_ranges):
                     current_start, current_end = highlighted_ranges[range_index]
@@ -561,7 +581,7 @@
                     current_start = current_end = None
                     break
             # Skip characters that fall inside a highlighted range.
             if current_start is not None and current_start <= i < current_end:
                 continue
             if char in FRENCH_PUNCTUATION:
                 if i == 0:

weblate/checks/defaults.py

@@ -6,6 +6,7 @@
 
 DEFAULT_CHECK_LIST: tuple[str, ...] = (
     "weblate.checks.same.SameCheck",
+    "weblate.checks.chars.AcceleratorKeyCheck",
     "weblate.checks.chars.BeginNewlineCheck",
     "weblate.checks.chars.EndNewlineCheck",
     "weblate.checks.chars.BeginSpaceCheck",

weblate/checks/tests/test_chars_checks.py

@@ -7,6 +7,7 @@
 from django.test import SimpleTestCase
 
 from weblate.checks.chars import (
+    AcceleratorKeyCheck,
     BeginNewlineCheck,
     BeginSpaceCheck,
     DoubleSpaceCheck,
@@ -32,6 +33,34 @@
 from weblate.trans.tests.factories import make_check, make_unit
 
 
+class AcceleratorKeyCheckTest(CheckTestCase):
+    check = AcceleratorKeyCheck()
+
+    def setUp(self) -> None:
+        super().setUp()
+        self.test_good_matching = ("&File", "&File", "accelerators")
+        self.test_good_none = ("File", "File", "accelerators")
+        self.test_good_flag = ("&File", "File", "")
+        self.test_failure_1 = ("&File", "File", "accelerators")
+        self.test_failure_2 = ("File", "&File", "accelerators")
+        self.test_failure_3 = ("&File", "&File &Edit", "accelerators")
+
+    def test_underscore_accelerator(self) -> None:
+        self.do_test(False, ("_File", "_File", "accelerators"))
+        self.do_test(True, ("_File", "File", "accelerators"))
+        self.do_test(True, ("File", "_File", "accelerators"))
+
+    def test_literal_ampersand(self) -> None:
+        # A balanced, literal ampersand is not treated as an accelerator key.
+        self.do_test(False, ("Walter & Sons", "Walter & Sons", "accelerators"))
+
+    def test_multiple_accelerators(self) -> None:
+        # More than one accelerator in the target is reported even if counts match.
+        self.do_test(True, ("&File &Edit", "&File &Edit", "accelerators"))
+        # A mismatched marker type (& vs _) is reported.
+        self.do_test(True, ("&File", "_File", "accelerators"))
+
+
 class BeginNewlineCheckTest(CheckTestCase):
     check = BeginNewlineCheck()
 

weblate/settings_example.py

@@ -728,6 +728,7 @@
 # List of quality checks
 # CHECK_LIST = (
 #     "weblate.checks.same.SameCheck",
+#     "weblate.checks.chars.AcceleratorKeyCheck",
 #     "weblate.checks.chars.BeginNewlineCheck",
 #     "weblate.checks.chars.EndNewlineCheck",
 #     "weblate.checks.chars.BeginSpaceCheck",