devutils/i18n: add clean command (#1869)

devutils/i18n.py

@@ -48,6 +48,8 @@ def parse_args():
                            help='Import translations from a JSON file '
                            'instead of calling the LLM.')
 
+    subparsers.add_parser('clean', help='Clean up stale translation strings')
+
     return parser.parse_args()
 
 
@@ -63,6 +65,10 @@ def main():
         import i18n_translate # pylint: disable=import-outside-toplevel
         return i18n_translate.run(args)
 
+    if args.command == 'clean':
+        import i18n_clean # pylint: disable=import-outside-toplevel
+        return i18n_clean.run()
+
     raise ValueError(f'unknown command: {args.command}')
 
 

devutils/i18n_clean.py

@@ -0,0 +1,53 @@
+# Copyright 2026 The Helium Authors
+# You can use, redistribute, and/or modify this source code under
+# the terms of the GPL-3.0 license that can be found in the LICENSE file.
+"""Helper for cleaning up obsolete and outdated translation strings."""
+
+import json
+from pathlib import Path
+
+I18N_DIR = Path(__file__).resolve().parent.parent / 'i18n'
+SOURCE_PATH = I18N_DIR / 'source.gen.json'
+TRANSLATIONS_DIR = I18N_DIR / 'translations'
+
+
+def clean_translation_file(lang, source_keys):
+    """Clean up outdated and duplicated translations in a language file."""
+    path = TRANSLATIONS_DIR / f'{lang}.json'
+    with open(path, encoding='utf-8') as file:
+        entries = json.load(file)
+
+    translation_keys = set()
+    result = []
+    n_filtered = 0
+    for entry in entries:
+        key = (entry['name'], entry['source'])
+        if key in source_keys and key not in translation_keys:
+            result.append(entry)
+            translation_keys.add(key)
+        else:
+            n_filtered += 1
+
+    if n_filtered > 0:
+        with open(path, 'w', encoding='utf-8') as file:
+            json.dump(result, file, indent=2, ensure_ascii=False)
+            file.write('\n')
+
+    return n_filtered
+
+
+def run():
+    """Clean up outdated translation strings."""
+    with open(SOURCE_PATH, encoding='utf-8') as file:
+        source = json.load(file)
+    with open(I18N_DIR / 'languages.json', encoding='utf-8') as file:
+        languages = json.load(file)
+
+    existing_keys = set()
+    for entry in source:
+        existing_keys.add((entry['name'], entry['message']))
+
+    for lang in languages:
+        n_filtered = clean_translation_file(lang, existing_keys)
+        if n_filtered:
+            print(f'{lang}: filtered {n_filtered} string(s)')