catch ApiValueError in some generic API calls

The motivation for this change is to handle bogus revision IDs in URLs,
which were causing 500 errors not 400 errors. Eg:

    https://qa.fatcat.wiki/file/rev/5d5d5162-b676-4f0a-968f-e19dadeaf96e%2B2019-11-27%2B13:49:51%2B0%2B6

I have no idea where these URLs are actually coming from, but they
should be 4xx not 5xx.

Investigating made me realize there is a whole category of ApiValueError
exceptions we were not catching and should have been.

2 files changed, 14 insertions, 2 deletions

diff --git a/python/fatcat_web/entity_helpers.py b/python/fatcat_web/entity_helpers.py
index 591dda80..30dd0f6d 100644
--- a/python/fatcat_web/entity_helpers.py
+++ b/python/fatcat_web/entity_helpers.py
@@ -1,6 +1,6 @@
 
 from flask import abort
-from fatcat_openapi_client.rest import ApiException
+from fatcat_openapi_client.rest import ApiException, ApiValueError
 from fatcat_tools.transforms import *
 from fatcat_web import app, api
 from fatcat_web.search import get_elastic_container_stats, get_elastic_container_random_releases
@@ -118,6 +118,8 @@ def generic_get_entity(entity_type, ident):
             raise NotImplementedError
     except ApiException as ae:
         abort(ae.status)
+    except ApiValueError:
+        abort(400)
 
 def generic_get_entity_revision(entity_type, revision_id):
     try:
@@ -139,6 +141,8 @@ def generic_get_entity_revision(entity_type, revision_id):
             raise NotImplementedError
     except ApiException as ae:
         abort(ae.status)
+    except ApiValueError:
+        abort(400)
 
 def generic_get_editgroup_entity(editgroup, entity_type, ident):
     if entity_type == 'container':
@@ -167,6 +171,12 @@ def generic_get_editgroup_entity(editgroup, entity_type, ident):
         # couldn't find relevent edit in this editgroup
         abort(404)
 
-    entity = generic_get_entity_revision(entity_type, revision_id)
+    try:
+        entity = generic_get_entity_revision(entity_type, revision_id)
+    except ApiException as ae:
+        abort(ae.status)
+    except ApiValueError:
+        abort(400)
+
     entity.ident = ident
     return entity, edit
diff --git a/python/tests/web_entity_views.py b/python/tests/web_entity_views.py
index 23a2b33b..e25c0296 100644
--- a/python/tests/web_entity_views.py
+++ b/python/tests/web_entity_views.py
@@ -42,6 +42,8 @@ def test_entity_basics(app):
         assert rv.status_code == 200
         rv = app.get('/{}/rev/{}'.format(entity_type, revision))
         assert rv.status_code == 200
+        rv = app.get('/{}/rev/{}_something'.format(entity_type, revision))
+        assert rv.status_code == 400
         rv = app.get('/{}/rev/{}/metadata'.format(entity_type, revision))
         assert rv.status_code == 200
         print('/editgroup/aaaaaaaaaaaabo53aaaaaaaaaq/{}/{}'.format(entity_type, ident))