Repository: yt-dlp/yt-dlp
File: yt_dlp/extractor/arte.py (Python)

Code before:
        for chapter in traverse_obj(config, ('data', 'attributes', 'chapters', 'elements'),
                                    expected_type=list) or []:
            cue = int_or_none(chapter.get('startTime'))
            if cue is not None:
                chapters.append({
                    'start_time': cue,
                    'title': chapter.get('title'),
                })

        return {
            'id': metadata['providerId'],
            'webpage_url': traverse_obj(metadata, ('link', 'url')),
            'title': traverse_obj(metadata, 'subtitle', 'title'),
            'alt_title': metadata.get('subtitle') and metadata.get('title'),
            'description': metadata.get('description'),
            'duration': traverse_obj(metadata, ('duration', 'seconds')),
            'language': metadata.get('language'),
            'timestamp': traverse_obj(config, ('data', 'attributes', 'rights', 'begin'), expected_type=parse_iso8601),
            'is_live': config['data']['attributes'].get('live', False),
            'formats': formats,
            'subtitles': subtitles,
            'thumbnails': [
                {'url': image['url'], 'id': image.get('caption')}
                for image in metadata.get('images') or [] if url_or_none(image.get('url'))
            ],
            'chapters': chapters,
        }


class ArteTVEmbedIE(InfoExtractor):
    _VALID_URL = r'https?://(?:www\.)?arte\.tv/player/v\d+/index\.php\?.*?\bjson_url=.+'
    _EMBED_REGEX = [r'<(?:iframe|script)[^>]+src=(["\'])(?P<url>(?:https?:)?//(?:www\.)?arte\.tv/player/v\d+/index\.php\?.*?\bjson_url=.+?)\1']
    _TESTS = [{
        'url': 'https://www.arte.tv/player/v5/index.php?json_url=https%3A%2F%2Fapi.arte.tv%2Fapi%2Fplayer%2Fv2%2Fconfig%2Fde%2F100605-013-A&lang=de&autoplay=true&mute=0100605-013-A',
        'info_dict': {
            'id': '100605-013-A',
            'ext': 'mp4',
            'title': 'United we Stream November Lockdown Edition #13',
            'description': 'md5:be40b667f45189632b78c1425c7c2ce1',
            'upload_date': '20201116',
        },
        'skip': 'No video available'
    }, {
        'url': 'https://www.arte.tv/player/v3/index.php?json_url=https://api.arte.tv/api/player/v2/config/de/100605-013-A',
        'only_matching': True,
    }]

    def _real_extract(self, url):
        qs = parse_qs(url)
        json_url = qs['json_url'][0]
        video_id = ArteTVIE._match_id(json_url)

Review comment (suggestion):
you were right to do this originally, since not every video has chapters. then you can remove `chapters: []` from the first two tests. my bad
```suggestion
            'chapters': chapters or None,
```

Code after:
            'webpage_url': traverse_obj(metadata, ('link', 'url')),
            'title': traverse_obj(metadata, 'subtitle', 'title'),
            'alt_title': metadata.get('subtitle') and metadata.get('title'),
            'description': metadata.get('description'),
            'duration': traverse_obj(metadata, ('duration', 'seconds')),
            'language': metadata.get('language'),
            'timestamp': traverse_obj(config, ('data', 'attributes', 'rights', 'begin'), expected_type=parse_iso8601),
            'is_live': config['data']['attributes'].get('live', False),
            'formats': formats,
            'subtitles': subtitles,
            'thumbnails': [
                {'url': image['url'], 'id': image.get('caption')}
                for image in metadata.get('images') or [] if url_or_none(image.get('url'))
            ],
            # TODO: chapters may also be in stream['segments']?
            'chapters': traverse_obj(config, ('data', 'attributes', 'chapters', 'elements', ..., {
                'start_time': 'startTime',
                'title': 'title',
            })) or None,
        }


class ArteTVEmbedIE(InfoExtractor):
    _VALID_URL = r'https?://(?:www\.)?arte\.tv/player/v\d+/index\.php\?.*?\bjson_url=.+'
    _EMBED_REGEX = [r'<(?:iframe|script)[^>]+src=(["\'])(?P<url>(?:https?:)?//(?:www\.)?arte\.tv/player/v\d+/index\.php\?.*?\bjson_url=.+?)\1']
    _TESTS = [{
        'url': 'https://www.arte.tv/player/v5/index.php?json_url=https%3A%2F%2Fapi.arte.tv%2Fapi%2Fplayer%2Fv2%2Fconfig%2Fde%2F100605-013-A&lang=de&autoplay=true&mute=0100605-013-A',
        'info_dict': {
            'id': '100605-013-A',
            'ext': 'mp4',
            'title': 'United we Stream November Lockdown Edition #13',
            'description': 'md5:be40b667f45189632b78c1425c7c2ce1',
            'upload_date': '20201116',
        },
        'skip': 'No video available'
    }, {
        'url': 'https://www.arte.tv/player/v3/index.php?json_url=https://api.arte.tv/api/player/v2/config/de/100605-013-A',
        'only_matching': True,
    }]

    def _real_extract(self, url):
        qs = parse_qs(url)
        json_url = qs['json_url'][0]
        video_id = ArteTVIE._match_id(json_url)
        return self.url_result(
            json_url, ie=ArteTVIE.ie_key(), video_id=video_id)


class ArteTVPlaylistIE(ArteTVBaseIE):
    _VALID_URL = r'https?://(?:www\.)?arte\.tv/(?P<lang>%s)/videos/(?P<id>RC-\d{6})' % ArteTVBaseIE._ARTE_LANGUAGES
    _TESTS = [{