Refactoring API error handling

supysonic/api/__init__.py

@@ -30,6 +30,7 @@ from pony.orm import ObjectNotFound
 from ..managers.user import UserManager
 from ..py23 import dict
 
+from .exceptions import Unauthorized
 from .formatters import JSONFormatter, JSONPFormatter, XMLFormatter
 
 api = Blueprint('api', __name__)
@@ -56,33 +57,28 @@ def decode_password(password):
 
 @api.before_request
 def authorize():
-    error = request.formatter.error(40, 'Unauthorized'), 401
-
     if request.authorization:
         status, user = UserManager.try_auth(request.authorization.username, request.authorization.password)
         if status == UserManager.SUCCESS:
             request.username = request.authorization.username
             request.user = user
             return
+        raise Unauthorized()
 
-    (username, password) = map(request.values.get, [ 'u', 'p' ])
+    username = request.values['u']
-    if not username or not password:
+    password = request.values['p']
-        return error
-
     password = decode_password(password)
+
     status, user = UserManager.try_auth(username, password)
     if status != UserManager.SUCCESS:
-        return error
+        raise Unauthorized()
 
     request.username = username
     request.user = user
 
 @api.before_request
 def get_client_prefs():
-    if 'c' not in request.values:
+    client = request.values['c']
-        return request.formatter.error(10, 'Missing required parameter')
-
-    client = request.values.get('c')
     try:
         ClientPrefs[request.user, client]
     except ObjectNotFound:
@@ -90,24 +86,13 @@ def get_client_prefs():
 
     request.client = client
 
-#@api.errorhandler(404)
-@api.route('/<path:invalid>', methods = [ 'GET', 'POST' ]) # blueprint 404 workaround
-def not_found(*args, **kwargs):
-    return request.formatter.error(0, 'Not implemented'), 501
-
 def get_entity(cls, param = 'id'):
-    eid = request.values.get(param)
+    eid = request.values[param]
-    if not eid:
-        return False, request.formatter.error(10, 'Missing %s id' % cls.__name__)
-
-    try:
     eid = uuid.UUID(eid)
     entity = cls[eid]
-        return True, entity
+    return entity
-    except ValueError:
+
-        return False, request.formatter.error(0, 'Invalid %s id' % cls.__name__)
+from .errors import *
-    except ObjectNotFound:
-        return False, (request.formatter.error(70, '%s not found' % cls.__name__), 404)
 
 from .system import *
 from .browse import *

supysonic/api/albums_songs.py

@@ -35,13 +35,10 @@ def rand_songs():
     size = request.values.get('size', '10')
     genre, fromYear, toYear, musicFolderId = map(request.values.get, [ 'genre', 'fromYear', 'toYear', 'musicFolderId' ])
 
-    try:
     size = int(size) if size else 10
     fromYear = int(fromYear) if fromYear else None
     toYear = int(toYear) if toYear else None
     fid = uuid.UUID(musicFolderId) if musicFolderId else None
-    except ValueError:
-        return request.formatter.error(0, 'Invalid parameter format')
 
     query = Track.select()
     if fromYear:
@@ -65,11 +62,9 @@ def album_list():
     ltype, size, offset = map(request.values.get, [ 'type', 'size', 'offset' ])
     if not ltype:
         return request.formatter.error(10, 'Missing type')
-    try:
+
     size = int(size) if size else 10
     offset = int(offset) if offset else 0
-    except ValueError:
-        return request.formatter.error(0, 'Invalid parameter format')
 
     query = select(t.folder for t in Track)
     if ltype == 'random':
@@ -102,11 +97,9 @@ def album_list_id3():
     ltype, size, offset = map(request.values.get, [ 'type', 'size', 'offset' ])
     if not ltype:
         return request.formatter.error(10, 'Missing type')
-    try:
+
     size = int(size) if size else 10
     offset = int(offset) if offset else 0
-    except ValueError:
-        return request.formatter.error(0, 'Invalid parameter format')
 
     query = Album.select()
     if ltype == 'random':

supysonic/api/annotation.py

@@ -175,10 +175,7 @@ def rate():
 
 @api.route('/scrobble.view', methods = [ 'GET', 'POST' ])
 def scrobble():
-    status, res = get_entity(Track)
+    res = get_entity(Track)
-    if not status:
-        return res
-
     t, submission = map(request.values.get, [ 'time', 'submission' ])
 
     if t:

supysonic/api/browse.py

@@ -43,23 +43,16 @@ def list_indexes():
     musicFolderId = request.values.get('musicFolderId')
     ifModifiedSince = request.values.get('ifModifiedSince')
     if ifModifiedSince:
-        try:
         ifModifiedSince = int(ifModifiedSince) / 1000
-        except ValueError:
-            return request.formatter.error(0, 'Invalid timestamp')
 
     if musicFolderId is None:
         folders = Folder.select(lambda f: f.root)[:]
     else:
-        try:
         mfid = uuid.UUID(musicFolderId)
         folder = Folder[mfid]
-        except ValueError:
-            return request.formatter.error(0, 'Invalid id')
-        except ObjectNotFound:
-            return request.formatter.error(70, 'Folder not found')
         if not folder.root:
-            return request.formatter.error(70, 'Folder not found')
+            raise ObjectNotFound(Folder, mfid)
+
         folders = [ folder ]
 
     last_modif = max(map(lambda f: f.last_scan, folders))
@@ -100,10 +93,7 @@ def list_indexes():
 
 @api.route('/getMusicDirectory.view', methods = [ 'GET', 'POST' ])
 def show_directory():
-    status, res = get_entity(Folder)
+    res = get_entity(Folder)
-    if not status:
-        return res
-
     directory = dict(
         id = str(res.id),
         name = res.name,
@@ -139,10 +129,7 @@ def list_artists():
 
 @api.route('/getArtist.view', methods = [ 'GET', 'POST' ])
 def artist_info():
-    status, res = get_entity(Artist)
+    res = get_entity(Artist)
-    if not status:
-        return res
-
     info = res.as_subsonic_artist(request.user)
     albums  = set(res.albums)
     albums |= { t.album for t in res.tracks }
@@ -152,10 +139,7 @@ def artist_info():
 
 @api.route('/getAlbum.view', methods = [ 'GET', 'POST' ])
 def album_info():
-    status, res = get_entity(Album)
+    res = get_entity(Album)
-    if not status:
-        return res
-
     info = res.as_subsonic_album(request.user)
     info['song'] = [ t.as_subsonic_child(request.user, request.client) for t in sorted(res.tracks, key = lambda t: t.sort_key()) ]
 
@@ -163,10 +147,7 @@ def album_info():
 
 @api.route('/getSong.view', methods = [ 'GET', 'POST' ])
 def track_info():
-    status, res = get_entity(Track)
+    res = get_entity(Track)
-    if not status:
-        return res
-
     return request.formatter('song', res.as_subsonic_child(request.user, request.client))
 
 @api.route('/getVideos.view', methods = [ 'GET', 'POST' ])

supysonic/api/chat.py

@@ -27,10 +27,7 @@ from . import api
 @api.route('/getChatMessages.view', methods = [ 'GET', 'POST' ])
 def get_chat():
     since = request.values.get('since')
-    try:
     since = int(since) / 1000 if since else None
-    except ValueError:
-        return request.formatter.error(0, 'Invalid parameter')
 
     query = ChatMessage.select().order_by(ChatMessage.time)
     if since:

supysonic/api/errors.py

@@ -0,0 +1,45 @@
+# coding: utf-8
+#
+# This file is part of Supysonic.
+# Supysonic is a Python implementation of the Subsonic server API.
+#
+# Copyright (C) 2018 Alban 'spl0k' Féron
+#
+# Distributed under terms of the GNU AGPLv3 license.
+
+from flask import current_app
+from pony.orm import rollback
+from pony.orm import ObjectNotFound
+from werkzeug.exceptions import BadRequestKeyError
+
+from . import api
+from .exceptions import GenericError, MissingParameter, NotFound
+
+@api.errorhandler(ValueError)
+def value_error(e):
+    rollback()
+    return GenericError(e)
+
+@api.errorhandler(BadRequestKeyError)
+def key_error(e):
+    rollback()
+    return MissingParameter(e.args[0])
+
+@api.errorhandler(ObjectNotFound)
+def not_found(e):
+    rollback()
+    return NotFound(e.entity.__name__)
+
+@api.errorhandler(Exception)
+def generic_error(e): # pragma: nocover
+    rollback()
+    if not current_app.testing:
+        return GenericError(e), 500
+    else:
+        raise e
+
+#@api.errorhandler(404)
+@api.route('/<path:invalid>', methods = [ 'GET', 'POST' ]) # blueprint 404 workaround
+def not_found(*args, **kwargs):
+    return GenericError('Not implemented'), 501
+

supysonic/api/exceptions.py

@@ -0,0 +1,74 @@
+# coding: utf-8
+#
+# This file is part of Supysonic.
+# Supysonic is a Python implementation of the Subsonic server API.
+#
+# Copyright (C) 2018 Alban 'spl0k' Féron
+#
+# Distributed under terms of the GNU AGPLv3 license.
+
+from flask import request
+from werkzeug.exceptions import HTTPException
+
+class SubsonicAPIError(HTTPException):
+    code = 400
+    api_code = None
+    message = None
+
+    def get_response(self, environ = None):
+        rv = request.formatter.error(self.api_code, self.message)
+        rv.status_code = self.code
+        return rv
+
+    def __str__(self):
+        code = self.api_code if self.api_code is not None else '??'
+        return '{}: {}'.format(code, self.message)
+
+class GenericError(SubsonicAPIError):
+    api_code = 0
+
+    def __init__(self, message, *args, **kwargs):
+        super(GenericError, self).__init__(*args, **kwargs)
+        self.message = message
+
+class MissingParameter(SubsonicAPIError):
+    api_code = 10
+
+    def __init__(self, param, *args, **kwargs):
+        super(MissingParameter, self).__init__(*args, **kwargs)
+        self.message = "Required parameter '{}' is missing.".format(param)
+
+class ClientMustUpgrade(SubsonicAPIError):
+    api_code = 20
+    message = 'Incompatible Subsonic REST protocol version. Client must upgrade.'
+
+class ServerMustUpgrade(SubsonicAPIError):
+    code = 501
+    api_code = 30
+    message = 'Incompatible Subsonic REST protocol version. Server must upgrade.'
+
+class Unauthorized(SubsonicAPIError):
+    code = 401
+    api_code = 40
+    message = 'Wrong username or password.'
+
+class Forbidden(SubsonicAPIError):
+    code = 403
+    api_code = 50
+    message = 'User is not authorized for the given operation.'
+
+class TrialExpired(SubsonicAPIError):
+    code = 402
+    api_code = 60
+    message = ("The trial period for the Supysonic server is over."
+        "But since it doesn't use any licensing you shouldn't be seeing this error ever."
+        "So something went wrong or you got scammed.")
+
+class NotFound(SubsonicAPIError):
+    code = 404
+    api_code = 70
+
+    def __init__(self, entity, *args, **kwargs):
+        super(NotFound, self).__init__(*args, **kwargs)
+        self.message = '{} not found'.format(entity)
+

supysonic/api/media.py

@@ -47,9 +47,7 @@ def prepare_transcoding_cmdline(base_cmdline, input_file, input_format, output_f
 
 @api.route('/stream.view', methods = [ 'GET', 'POST' ])
 def stream_media():
-    status, res = get_entity(Track)
+    res = get_entity(Track)
-    if not status:
-        return res
 
     maxBitRate, format, timeOffset, size, estimateContentLength = map(request.values.get, [ 'maxBitRate', 'format', 'timeOffset', 'size', 'estimateContentLength' ])
     if format:
@@ -67,10 +65,7 @@ def stream_media():
         dst_bitrate = prefs.bitrate
 
     if maxBitRate:
-        try:
         maxBitRate = int(maxBitRate)
-        except ValueError:
-            return request.formatter.error(0, 'Invalid bitrate value')
 
         if dst_bitrate > maxBitRate and maxBitRate != 0:
             dst_bitrate = maxBitRate
@@ -133,27 +128,18 @@ def stream_media():
 
 @api.route('/download.view', methods = [ 'GET', 'POST' ])
 def download_media():
-    status, res = get_entity(Track)
+    res = get_entity(Track)
-    if not status:
-        return res
-
     return send_file(res.path, mimetype = res.content_type, conditional=True)
 
 @api.route('/getCoverArt.view', methods = [ 'GET', 'POST' ])
 def cover_art():
-    status, res = get_entity(Folder)
+    res = get_entity(Folder)
-    if not status:
-        return res
-
     if not res.has_cover_art or not os.path.isfile(os.path.join(res.path, 'cover.jpg')):
         return request.formatter.error(70, 'Cover art not found')
 
     size = request.values.get('size')
     if size:
-        try:
         size = int(size)
-        except ValueError:
-            return request.formatter.error(0, 'Invalid size value')
     else:
         return send_file(os.path.join(res.path, 'cover.jpg'))
 

supysonic/api/playlists.py

@@ -21,8 +21,6 @@
 import uuid
 
 from flask import request
-from pony.orm import rollback
-from pony.orm import ObjectNotFound
 
 from ..db import Playlist, User, Track
 from ..py23 import dict
@@ -48,10 +46,7 @@ def list_playlists():
 
 @api.route('/getPlaylist.view', methods = [ 'GET', 'POST' ])
 def show_playlist():
-    status, res = get_entity(Playlist)
+    res = get_entity(Playlist)
-    if not status:
-        return res
-
     if res.user.id != request.user.id and not request.user.admin:
         return request.formatter.error('50', 'Private playlist')
 
@@ -64,16 +59,10 @@ def create_playlist():
     playlist_id, name = map(request.values.get, [ 'playlistId', 'name' ])
     # songId actually doesn't seem to be required
     songs = request.values.getlist('songId')
-    try:
     playlist_id = uuid.UUID(playlist_id) if playlist_id else None
-    except ValueError:
-        return request.formatter.error(0, 'Invalid playlist id')
 
     if playlist_id:
-        try:
         playlist = Playlist[playlist_id]
-        except ObjectNotFound:
-            return request.formatter.error(70, 'Unknwon playlist')
 
         if playlist.user.id != request.user.id and not request.user.admin:
             return request.formatter.error(50, "You're not allowed to modify a playlist that isn't yours")
@@ -86,26 +75,16 @@ def create_playlist():
     else:
         return request.formatter.error(10, 'Missing playlist id or name')
 
-    try:
     songs = map(uuid.UUID, songs)
     for sid in songs:
         track = Track[sid]
         playlist.add(track)
-    except ValueError:
-        rollback()
-        return request.formatter.error(0, 'Invalid song id')
-    except ObjectNotFound:
-        rollback()
-        return request.formatter.error(70, 'Unknown song')
 
     return request.formatter.empty
 
 @api.route('/deletePlaylist.view', methods = [ 'GET', 'POST' ])
 def delete_playlist():
-    status, res = get_entity(Playlist)
+    res = get_entity(Playlist)
-    if not status:
-        return res
-
     if res.user.id != request.user.id and not request.user.admin:
         return request.formatter.error(50, "You're not allowed to delete a playlist that isn't yours")
 
@@ -114,10 +93,7 @@ def delete_playlist():
 
 @api.route('/updatePlaylist.view', methods = [ 'GET', 'POST' ])
 def update_playlist():
-    status, res = get_entity(Playlist, 'playlistId')
+    res = get_entity(Playlist, 'playlistId')
-    if not status:
-        return res
-
     if res.user.id != request.user.id and not request.user.admin:
         return request.formatter.error(50, "You're not allowed to delete a playlist that isn't yours")
 
@@ -132,7 +108,6 @@ def update_playlist():
     if public:
         playlist.public = public in (True, 'True', 'true', 1, '1')
 
-    try:
     to_add = map(uuid.UUID, to_add)
     to_remove = map(int, to_remove)
 
@@ -141,10 +116,6 @@ def update_playlist():
         playlist.add(track)
 
     playlist.remove_at_indexes(to_remove)
-    except ValueError:
-        return request.formatter.error(0, 'Invalid parameter')
-    except ObjectNotFound:
-        return request.formatter.error(70, 'Unknown song')
 
     return request.formatter.empty
 

supysonic/api/search.py

@@ -30,13 +30,10 @@ from . import api
 @api.route('/search.view', methods = [ 'GET', 'POST' ])
 def old_search():
     artist, album, title, anyf, count, offset, newer_than = map(request.values.get, [ 'artist', 'album', 'title', 'any', 'count', 'offset', 'newerThan' ])
-    try:
+
     count = int(count) if count else 20
     offset = int(offset) if offset else 0
     newer_than = int(newer_than) / 1000 if newer_than else 0
-    except ValueError:
-        return request.formatter.error(0, 'Invalid parameter')
-
     min_date = datetime.fromtimestamp(newer_than)
 
     if artist:
@@ -74,15 +71,12 @@ def new_search():
     query, artist_count, artist_offset, album_count, album_offset, song_count, song_offset = map(
         request.values.get, [ 'query', 'artistCount', 'artistOffset', 'albumCount', 'albumOffset', 'songCount', 'songOffset' ])
 
-    try:
     artist_count =  int(artist_count)  if artist_count  else 20
     artist_offset = int(artist_offset) if artist_offset else 0
     album_count =   int(album_count)   if album_count   else 20
     album_offset =  int(album_offset)  if album_offset  else 0
     song_count =    int(song_count)    if song_count    else 20
     song_offset =   int(song_offset)   if song_offset   else 0
-    except ValueError:
-        return request.formatter.error(0, 'Invalid parameter')
 
     if not query:
         return request.formatter.error(10, 'Missing query parameter')
@@ -102,15 +96,12 @@ def search_id3():
     query, artist_count, artist_offset, album_count, album_offset, song_count, song_offset = map(
         request.values.get, [ 'query', 'artistCount', 'artistOffset', 'albumCount', 'albumOffset', 'songCount', 'songOffset' ])
 
-    try:
     artist_count =  int(artist_count)  if artist_count  else 20
     artist_offset = int(artist_offset) if artist_offset else 0
     album_count =   int(album_count)   if album_count   else 20
     album_offset =  int(album_offset)  if album_offset  else 0
     song_count =    int(song_count)    if song_count    else 20
     song_offset =   int(song_offset)   if song_offset   else 0
-    except ValueError:
-        return request.formatter.error(0, 'Invalid parameter')
 
     if not query:
         return request.formatter.error(10, 'Missing query parameter')

tests/api/test_api_setup.py

@@ -63,9 +63,9 @@ class ApiSetupTestCase(TestBase):
     def test_auth_basic(self):
         # No auth info
         rv = self.client.get('/rest/ping.view?c=tests')
-        self.assertEqual(rv.status_code, 401)
+        self.assertEqual(rv.status_code, 400)
         self.assertIn('status="failed"', rv.data)
-        self.assertIn('code="40"', rv.data)
+        self.assertIn('code="10"', rv.data)
 
         self.__test_auth(self.__basic_auth_get)