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

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))