Add type hints for return values of functions in make_json_files method

scraper/src/youtube2zim/scraper.py

@@ -1141,7 +1141,7 @@ def video_has_channel(videos_channels, video):
         def get_thumbnail_path(video_id):
             return f"videos/{video_id}/video.webp"
 
-        def get_subtitles(video_id):
+        def get_subtitles(video_id) -> list[Subtitle]:
             video_dir = self.videos_dir.joinpath(video_id)
             languages = [
                 x.stem.split(".")[1]
@@ -1181,7 +1181,7 @@ def get_videos_list(playlist):
             videos = sorted(videos, key=lambda v: v["snippet"]["position"])
             return videos
 
-        def generate_video_object(video):
+        def generate_video_object(video) -> Video:
             video_id = video["contentDetails"]["videoId"]
             author = videos_channels[video_id]
             return Video(
@@ -1202,7 +1202,7 @@ def generate_video_object(video):
                 duration=0,
             )
 
-        def generate_video_preview_object(video):
+        def generate_video_preview_object(video) -> VideoPreview:
             video_id = video["contentDetails"]["videoId"]
             return VideoPreview(
                 slug=get_video_slug(video),
@@ -1212,12 +1212,12 @@ def generate_video_preview_object(video):
                 duration=0,
             )
 
-        def get_video_slug(video):
+        def get_video_slug(video) -> str:
             title = video["snippet"]["title"]
             video_id = video["contentDetails"]["videoId"]
             return f"{get_slug(title)}-{video_id[:4]}"
 
-        def generate_playlist_object(playlist):
+        def generate_playlist_object(playlist) -> Playlist:
             videos = get_videos_list(playlist)
             return Playlist(
                 id=playlist.playlist_id,
@@ -1237,7 +1237,7 @@ def generate_playlist_object(playlist):
                 ),
             )
 
-        def generate_playlist_preview_object(playlist):
+        def generate_playlist_preview_object(playlist) -> PlaylistPreview:
             videos = get_videos_list(playlist)
             return PlaylistPreview(
                 slug=get_playlist_slug(playlist),
@@ -1249,7 +1249,7 @@ def generate_playlist_preview_object(playlist):
                 count=len(videos),
             )
 
-        def get_playlist_slug(playlist):
+        def get_playlist_slug(playlist) -> str:
             return f"{get_slug(playlist.title)}-{playlist.playlist_id[-4:]}"
 
         videos = load_mandatory_json(self.cache_dir, "videos").values()