refactor: handle 404 exception with decorator and logically (#55)

Co-authored-by: tokitou-san <[email protected]>

app/api/decorators/return_decorator.py

@@ -1,3 +1,4 @@
+from fastapi import HTTPException
 import functools
 from collections.abc import Callable
 from typing import Any, TypeVar
@@ -13,10 +14,27 @@ def decorator(func: Callable[..., Any]) -> Callable[..., T]:
         def wrapper(*args: Any, **kwargs: Any) -> T:
             try:
                 return func(*args, **kwargs)
-
             except AttributeError:
                 return return_type
 
         return wrapper
 
     return decorator
+
+
+def return_on_404() -> Callable[..., Callable[..., Any]]:
+    def decorator(func: Callable[..., Any]) -> Callable[..., Any]:
+        @functools.wraps(func)
+        async def wrapper(*args: Any, **kwargs: Any) -> Any:
+            try:
+                return await func(*args, **kwargs)
+            # propagates HTTPException from function
+            except HTTPException as http_exception:
+                raise http_exception
+            # catches all other execptions
+            except Exception:
+                raise HTTPException(status_code=404, detail="Page not found")
+
+        return wrapper
+
+    return decorator

app/api/endpoints.py

@@ -3,6 +3,9 @@
 # helpers
 from .helpers.string import StringHelper
 
+# decorators
+from .decorators.return_decorator import return_on_404
+
 # scrapers
 from .scrapers.popular import PopularScraper
 from .scrapers.topten import TopTenScraper
@@ -24,91 +27,100 @@
 
 # router endpoints
 @router.get(
-    "/popular",
+    path="/popular",
     response_model=list[PopularMangaModel],
     summary="Popular Mangas",
     description="Get a list of Mangas which is popular/trending this season. Returns basic details of mangas, use its `slug` to get more details of Manga.",
 )
+@return_on_404()
 async def get_popular(offset: int = 0, limit: int = Query(10, le=10)):
     response = PopularScraper().scrape()
     return response[offset : offset + limit]
 
 
 @router.get(
-    "/top-10",
+    path="/top-10",
     response_model=list[TopTenMangaModel],
     summary="Top 10 Mangas",
     description="Get a list of Mangas which is top 10 this season. Returns basic details of mangas, use its `slug` to get more details of Manga.",
 )
+@return_on_404()
 async def get_top_ten(offset: int = 0, limit: int = Query(10, le=10)):
     response = TopTenScraper().scrape()
     return response[offset : offset + limit]
 
 
 @router.get(
-    "/most-viewed/{chart}",
+    path="/most-viewed/{chart}",
     response_model=list[MostViewedMangaModel],
     summary="Most Viewed Mangas",
     description="Get a list of Mangas which is most viewed by chart - `today` `week` `month`. Returns basic details of mangas, use its `slug` to get more details of Manga.",
 )
+@return_on_404()
 async def get_most_viewed(chart: str, offset: int = 0, limit: int = Query(10, le=10)):
     most_viewed_scraper = MostViewedScraper()
 
     if chart in most_viewed_scraper.CHARTS:
         response = most_viewed_scraper.scrape(chart)
         return response[offset : offset + limit]
     else:
-        message = f"Passed query ({chart}) is invalid. Valid queries {' | '.join(most_viewed_scraper.CHARTS)}"
-        status_code = 400
-
-        raise HTTPException(
-            detail={"message": message, "status_code": status_code},
-            status_code=status_code,
-        )
+        raise HTTPException(status_code=404, detail=f"Invalid chart {chart}")
 
 
 @router.get(
-    "/manga/{slug}",
+    path="/manga/{slug}",
     response_model=MangaModel,
     summary="Manga",
     description="Get more details about a specific Manga by `slug`, eg: `/manga/one-piece-3/` - returns the full details of that specific Manga.",
 )
+@return_on_404()
 async def get_manga(slug: str):
-    response = BaseMangaScraper(url=f"https://mangareader.to/{slug}").build_dict()
+    response = BaseMangaScraper(url=f"https://mangareader.to/{slug}").scrape()
+
+    if not response["title"]:
+        raise HTTPException(status_code=404, detail=f"Manga with slug {slug} was not found")
     return response
 
 
 @router.get(
-    "/search",
+    path="/search",
     response_model=list[BaseSearchModel],
     summary="Search Mangas",
     description="Search Mangas with a `keyword` as query. eg: `/search/?keyword=one piece/` - returns a list of Mangas according to this keyword.",
 )
+@return_on_404()
 async def search(
     keyword: str, page: int = 1, offset: int = 0, limit: int = Query(10, le=18)
 ):
     url = f"https://mangareader.to/search?keyword={keyword}&page={page}"
     response = BaseSearchScraper(url).scrape()
+
+    if not response:
+        raise HTTPException(
+            status_code=404, detail=f"Manga with keyword {keyword} was not found"
+        )
     return response[offset : offset + limit]
 
 
 @router.get(
-    "/random",
+    path="/random",
     response_model=MangaModel,
     summary="Random",
     description="Get details about random Manga. Returns a `dict` of randomly picked Manga. Note: some fields might be `null` because all animes are not registered properly in database.",
 )
+@return_on_404()
 async def random():
-    response = BaseMangaScraper(url="https://mangareader.to/random/").build_dict()
+    response = BaseMangaScraper(url="https://mangareader.to/random/").scrape()
     return response
 
 
 @router.get(
-    "/completed",
+    path="/completed",
     response_model=list[BaseSearchModel],
     summary="Completed Mangas",
     description="Get list of completed airing Mangas. eg: `/completed/` - returns a list of Mangas which is completed airing lately. Also has `sort` query which get each pages of Mangas ( 1 page contains 18 Mangas ): valid `sort` queries - `default` `last-updated` `score` `name-az` `release-date` `most-viewed`.",
 )
+@return_on_404()
 async def completed(
     page: int = 1, sort: str = "default", offset: int = 0, limit: int = Query(10, le=18)
 ):
@@ -119,11 +131,12 @@ async def completed(
 
 
 @router.get(
-    "/genre/{genre}",
+    path="/genre/{genre}",
     response_model=list[BaseSearchModel],
     summary="Genre",
     description="Search Mangas with genres. eg: `/genre/action/` - returns a list of Mangas with genre `action`. Also has `sort` query which get each pages of Mangas ( 1 page contains 18 Mangas ): valid `sort` queries - `default` `last-updated` `score` `name-az` `release-date` `most-viewed`.",
 )
+@return_on_404()
 async def genre(
     genre: str,
     page: int = 1,
@@ -134,16 +147,22 @@ async def genre(
     slugified_sort = string_helper.slugify(sort, "-")
     url = f"https://mangareader.to/genre/{genre}/?sort={slugified_sort}&page={page}"
     response = BaseSearchScraper(url).scrape()
+
+    if not response:
+        raise HTTPException(
+            status_code=404, detail=f"Manga with genre {genre} was not found"
+        )
     return response[offset : offset + limit]
 
 
 @router.get(
-    "/type/{type}",
+    path="/type/{type}",
     response_model=list[BaseSearchModel],
     summary="Type",
     description="Search Mangas with types. eg: `/type/manga/` - returns a list of Mangas with type `manga`. Also has `page` query which get each pages of Mangas ( 1 page contains 18 Mangas ): valid `type` queries - `manga`, `one-shot`, `doujinshi`, `light-novel`, `manhwa`, `manhua`, `comic`.",
 )
-def type(
+@return_on_404()
+async def type(
     type: str,
     page: int = 1,
     sort: str = "default",
@@ -154,4 +173,7 @@ def type(
     slugified_sort = string_helper.slugify(sort, "-")
     url = f"https://mangareader.to/type/{slugified_type}?sort={slugified_sort}&page={page}"
     response = BaseSearchScraper(url).scrape()
+
+    if not response:
+        raise HTTPException(status_code=404, detail=f"Manga of type {type} was not found")
     return response[offset : offset + limit]

app/api/scrapers/base_manga.py

@@ -138,7 +138,7 @@ def get_volumes(self):
         return item_list
 
     @return_on_error({})
-    def build_dict(self) -> dict:
+    def scrape(self) -> dict:
         manga_dict = {
             "manga_id": self.get_manga_id,
             "title": self.get_title,