Refactor the Micropub error responses into a non-view module, have them produce an immediately raise-able exception

entries/from_url.py

@@ -3,8 +3,7 @@ from urllib.parse import urlparse
 from django.contrib.sites.models import Site
 from django.http import HttpResponse
 from django.urls import resolve, Resolver404
-from micropub.views import error
-from lemoncurry.middleware import ResponseException
+from micropub import error
 
 from .models import Entry
 
@@ -12,24 +11,24 @@ from .models import Entry
 def from_url(url: str) -> Entry:
     domain = Site.objects.get_current().domain
     if not url:
-        raise ResponseException(error.bad_req('url parameter required'))
+        raise error.bad_req('url parameter required')
     if '//' not in url:
         url = '//' + url
     parts = urlparse(url, scheme='https')
     if parts.scheme not in ('http', 'https') or parts.netloc != domain:
-        raise ResponseException(error.bad_req('url does not point to this site'))
+        raise error.bad_req('url does not point to this site')
 
     try:
         match = resolve(parts.path)
     except Resolver404:
-        raise ResponseException(error.bad_req('url does not point to a valid page on this site'))
+        raise error.bad_req('url does not point to a valid page on this site')
 
     if match.view_name != 'entries:entry':
-        raise ResponseException(error.bad_req('url does not point to an entry on this site'))
+        raise error.bad_req('url does not point to an entry on this site')
 
     try:
         entry = Entry.objects.get(pk=match.kwargs['id'])
     except Entry.DoesNotExist:
-        raise ResponseException(error.bad_req('url does not point to an existing entry'))
+        raise error.bad_req('url does not point to an existing entry')
 
     return entry

lemonauth/tokens.py

@@ -1,31 +1,26 @@
-from lemoncurry.middleware import ResponseException
-from micropub.views import error
+from micropub import error
 from .models import IndieAuthCode, Token
 
 
-def auth(request):
+def auth(request) -> Token:
     if 'HTTP_AUTHORIZATION' in request.META:
         auth = request.META.get('HTTP_AUTHORIZATION').split(' ')
         if auth[0] != 'Bearer':
-            raise ResponseException(error.bad_req(
-                'auth type {0} not supported'.format(auth[0])
-            ))
+            raise error.bad_req('auth type {0} not supported'.format(auth[0]))
         if len(auth) != 2:
-            raise ResponseException(error.bad_req(
-                'invalid Bearer auth format, must be Bearer <token>'
-            ))
+            raise error.bad_req('invalid Bearer auth format, must be Bearer <token>')
         token = auth[1]
     elif 'access_token' in request.POST:
         token = request.POST.get('access_token')
     elif 'access_token' in request.GET:
         token = request.GET.get('access_token')
     else:
-        raise ResponseException(error.unauthorized())
+        raise error.unauthorized()
 
     try:
         token = Token.objects.get(pk=token)
     except Token.DoesNotExist:
-        raise ResponseException(error.forbidden())
+        raise error.forbidden()
 
     return token
 

micropub/error.py

@@ -0,0 +1,36 @@
+from django.http import JsonResponse
+from lemoncurry.middleware import ResponseException
+from typing import Optional
+
+
+def forbidden() -> ResponseException:
+    return res('forbidden', 403)
+
+
+def unauthorized() -> ResponseException:
+    return res('unauthorized', 401)
+
+
+def bad_req(msg: str) -> ResponseException:
+    return res('invalid_request', msg=msg)
+
+
+def bad_type(type: str) -> ResponseException:
+    msg = 'unsupported request type {0}'.format(type)
+    return res('invalid_request', 415, msg)
+
+
+def bad_scope(scope: str) -> ResponseException:
+    return res('insufficient_scope', 401, scope=scope)
+
+
+def res(error: str,
+        status: Optional[int]=400,
+        msg: Optional[str]=None,
+        scope: Optional[str]=None):
+    content = {'error': error}
+    if msg is not None:
+        content['error_description'] = msg
+    if scope:
+        content['scope'] = scope
+    return ResponseException(JsonResponse(content, status=status))

micropub/views/__init__.py

@@ -26,6 +26,6 @@ def micropub(request):
     if request.content_type == 'application/json':
         request.json = json.load(request)
         action = request.json.get('action', 'create')
-    if action in actions:
-        return actions[action](request)
-    return error.bad_req('unknown action: {}'.format(action))
+    if action not in actions:
+        raise error.bad_req('unknown action: {}'.format(action))
+    return actions[action](request)

micropub/views/create.py

@@ -7,7 +7,7 @@ from entries.models import Cat, Entry
 from entries.kinds import Article, Note, Reply, Like, Repost
 from lemoncurry import utils
 
-from . import error
+from .. import error
 
 
 def form_to_mf2(request):
@@ -33,14 +33,14 @@ def create(request):
         'application/x-www-form-urlencoded': form_to_mf2,
     }
     if 'create' not in request.token:
-        return error.bad_scope('create')
+        raise error.bad_scope('create')
     if request.content_type not in normalise:
-        return error.unsupported_type(request.content_type)
+        raise error.unsupported_type(request.content_type)
     body = normalise[request.content_type](request)
     if 'type' not in body:
-        return error.bad_req('mf2 object type required')
+        raise error.bad_req('mf2 object type required')
     if body['type'] != ['h-entry']:
-        return error.bad_req('only h-entry supported')
+        raise error.bad_req('only h-entry supported')
 
     entry = Entry(author=request.token.user)
     props = body.get('properties', {})

micropub/views/delete.py

@@ -4,7 +4,7 @@ from ronkyuu import webmention
 from entries.from_url import from_url
 from entries.jobs import ping_hub, send_mentions
 
-from . import error
+from .. import error
 
 def delete(request):
     normalise = {
@@ -12,14 +12,14 @@ def delete(request):
         'application/x-www-form-urlencoded': lambda r: r.POST.get('url'),
     }
     if 'delete' not in request.token:
-        return error.bad_scope('delete')
+        raise error.bad_scope('delete')
     if request.content_type not in normalise:
-        return error.unsupported_type(request.content_type)
+        raise error.unsupported_type(request.content_type)
     url = normalise[request.content_type](request)
     entry = from_url(url)
 
     if entry.author != request.token.user:
-        return error.forbid('entry belongs to another user')
+        raise error.forbid('entry belongs to another user')
 
     perma = entry.absolute_url
     pings = entry.affected_urls

micropub/views/error.py

@@ -1,31 +0,0 @@
-from django.http import JsonResponse
-
-
-def forbidden():
-    return res('forbidden', 403)
-
-
-def unauthorized():
-    return res('unauthorized', 401)
-
-
-def bad_req(msg):
-    return res('invalid_request', msg=msg)
-
-
-def bad_type(type):
-    msg = 'unsupported request type {0}'.format(type)
-    return res('invalid_request', 415, msg)
-
-
-def bad_scope(scope):
-    return res('insufficient_scope', 401, scope=scope)
-
-
-def res(error, status=400, msg=None, scope=None):
-    content = {'error': error}
-    if msg:
-        content['error_description'] = msg
-    if scope:
-        content['scope'] = scope
-    return JsonResponse(content, status=status)

micropub/views/media.py

@@ -8,7 +8,7 @@ import magic
 
 from lemonauth import tokens
 from lemoncurry.utils import absolute_url
-from . import error
+from .. import error
 
 ACCEPTED_MEDIA_TYPES = (
     'image/gif',
@@ -22,12 +22,12 @@ ACCEPTED_MEDIA_TYPES = (
 def media(request):
     token = tokens.auth(request)
     if 'file' not in request.FILES:
-        return error.bad_req(
+        raise error.bad_req(
             "a file named 'file' must be provided to the media endpoint"
         )
     file = request.FILES['file']
     if file.content_type not in ACCEPTED_MEDIA_TYPES:
-        return error.bad_req(
+        raise error.bad_req(
             'unacceptable file type {0}'.format(file.content_type)
         )
 
@@ -39,7 +39,7 @@ def media(request):
         sha.update(chunk)
 
     if mime != file.content_type:
-        return error.bad_req(
+        raise error.bad_req(
             'detected file type {0} did not match specified file type {1}'
             .format(mime, file.content_type)
         )

micropub/views/query.py

@@ -1,9 +1,8 @@
 from django.http import JsonResponse
 from django.urls import reverse
 from lemoncurry import requests
-from lemoncurry.middleware import ResponseException
 from lemoncurry.utils import absolute_url
-from . import error
+from .. import error
 
 
 def config(request):
@@ -15,12 +14,10 @@ def config(request):
 def source(request):
     get = request.GET
     if 'url' not in get:
-        raise ResponseException(error.bad_req(
-            'must specify url parameter for source query'
-        ))
+        raise error.bad_req('must specify url parameter for source query')
     mf2 = requests.mf2(get['url']).to_dict(filter_by_type='h-entry')
     if not mf2:
-        raise ResponseException(error.bad_req('no h-entry at the requested url'))
+        raise error.bad_req('no h-entry at the requested url')
     entry = mf2[0]
     keys = get.getlist('properties', []) + get.getlist('properties[]', [])
     if not keys:
@@ -43,9 +40,9 @@ queries = {
 
 def query(request):
     if 'q' not in request.GET:
-        return error.bad_req('must specify q parameter')
+        raise error.bad_req('must specify q parameter')
     q = request.GET['q']
     if q not in queries:
-        return error.bad_req('unsupported query {0}'.format(q))
+        raise error.bad_req('unsupported query {0}'.format(q))
     res = queries[q](request)
     return JsonResponse(res)