[IMP] conftest: avoid parsing json it if may not be

When asserting a status fails, it's possible that this is a 400 or
500-type error which does not yield JSON data at all (e.g. forgot to
start the proxy or dummy), in which case trying to dump the json data
is actively harmful as it triggers cascading failures. And it's not
like the output message is formatted, so a re-structured assertion
message is not helpful.

conftest.py

@@ -585,14 +585,13 @@ class Repo:
         assert self.hook
         r = self._session.get(
             'https://api.github.com/repos/{}/hooks'.format(self.name))
-        response = r.json()
+        assert 200 <= r.status_code < 300, r.text
-        assert 200 <= r.status_code < 300, response
+        [hook] = r.json()
-        [hook] = response
 
         r = self._session.patch('https://api.github.com/repos/{}/hooks/{}'.format(self.name, hook['id']), json={
             'config': {**hook['config'], 'secret': secret},
         })
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
 
     def get_ref(self, ref):
         # differs from .commit(ref).id for the sake of assertion error messages
@@ -628,7 +627,7 @@ class Repo:
             ref = 'refs/' + ref
 
         r = self._session.get('https://api.github.com/repos/{}/commits/{}'.format(self.name, ref))
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
 
         return self._commit_from_gh(r.json())
 
@@ -650,14 +649,14 @@ class Repo:
         :rtype: Dict[str, str]
         """
         r = self._session.get('https://api.github.com/repos/{}/git/trees/{}'.format(self.name, commit.tree))
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
 
         # read tree's blobs
         tree = {}
         for t in r.json()['tree']:
             assert t['type'] == 'blob', "we're *not* doing recursive trees in test cases"
             r = self._session.get('https://api.github.com/repos/{}/git/blobs/{}'.format(self.name, t['sha']))
-            assert 200 <= r.status_code < 300, r.json()
+            assert 200 <= r.status_code < 300, r.text
             tree[t['path']] = base64.b64decode(r.json()['content']).decode()
 
         return tree
@@ -687,7 +686,7 @@ class Repo:
             'required_pull_request_reviews': None,
             'restrictions': None,
         })
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
 
     # FIXME: remove this (runbot_merge should use make_commits directly)
     def make_commit(self, ref, message, author, committer=None, tree=None, wait=True):
@@ -832,7 +831,7 @@ class Repo:
             },
             headers=headers,
         )
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
 
         return PR(self, r.json()['number'])
 
@@ -845,7 +844,7 @@ class Repo:
             'context': context,
             **kw
         })
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
 
     def is_ancestor(self, sha, of):
         return any(c['sha'] == sha for c in self.log(of))
@@ -856,7 +855,7 @@ class Repo:
                 'https://api.github.com/repos/{}/commits'.format(self.name),
                 params={'sha': ref_or_sha, 'page': page}
             )
-            assert 200 <= r.status_code < 300, r.json()
+            assert 200 <= r.status_code < 300, r.text
             yield from r.json()
             if not r.links.get('next'):
                 return
@@ -924,7 +923,7 @@ class PR:
             'https://api.github.com/repos/{}/pulls/{}'.format(self.repo.name, self.number),
             headers=caching
         )
-        assert r.ok, r.json()
+        assert r.ok, r.text
         if r.status_code == 304:
             return previous
         contents, caching = self._cache = r.json(), {}
@@ -969,7 +968,7 @@ class PR:
     @property
     def comments(self):
         r = self.repo._session.get('https://api.github.com/repos/{}/issues/{}/comments'.format(self.repo.name, self.number))
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
         return [Comment(c) for c in r.json()]
 
     @property
@@ -986,7 +985,7 @@ class PR:
             json={'body': body},
             headers=headers,
         )
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
         return r.json()['id']
 
     def edit_comment(self, cid, body, token=None):
@@ -999,7 +998,7 @@ class PR:
             json={'body': body},
             headers=headers
         )
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
         wait_for_hook()
 
     def delete_comment(self, cid, token=None):
@@ -1011,7 +1010,7 @@ class PR:
             'https://api.github.com/repos/{}/issues/comments/{}'.format(self.repo.name, cid),
             headers=headers
         )
-        assert r.status_code == 204, r.json()
+        assert r.status_code == 204, r.text
 
     def _set_prop(self, prop, value, token=None):
         assert self.repo.hook
@@ -1035,7 +1034,7 @@ class PR:
             self.repo.name,
             self.number,
         ))
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
         info = r.json()
 
         repo = self.repo
@@ -1056,7 +1055,7 @@ class PR:
             json={'body': body, 'event': state,},
             headers=headers
         )
-        assert 200 <= r.status_code < 300, r.json()
+        assert 200 <= r.status_code < 300, r.text
 
 PRBranch = collections.namedtuple('PRBranch', 'repo branch')
 class LabelsProxy(collections.abc.MutableSet):
@@ -1067,7 +1066,7 @@ class LabelsProxy(collections.abc.MutableSet):
     def _labels(self):
         pr = self._pr
         r = pr.repo._session.get('https://api.github.com/repos/{}/issues/{}/labels'.format(pr.repo.name, pr.number))
-        assert r.ok, r.json()
+        assert r.ok, r.text
         return {label['name'] for label in r.json()}
 
     def __repr__(self):
@@ -1093,14 +1092,14 @@ class LabelsProxy(collections.abc.MutableSet):
         r = pr.repo._session.post('https://api.github.com/repos/{}/issues/{}/labels'.format(pr.repo.name, pr.number), json={
             'labels': [label]
         })
-        assert r.ok, r.json()
+        assert r.ok, r.text
 
     def discard(self, label):
         pr = self._pr
         assert pr.repo.hook
         r = pr.repo._session.delete('https://api.github.com/repos/{}/issues/{}/labels/{}'.format(pr.repo.name, pr.number, label))
         # discard should do nothing if the item didn't exist in the set
-        assert r.ok or r.status_code == 404, r.json()
+        assert r.ok or r.status_code == 404, r.text
 
     def update(self, *others):
         pr = self._pr
@@ -1109,7 +1108,7 @@ class LabelsProxy(collections.abc.MutableSet):
         r = pr.repo._session.post('https://api.github.com/repos/{}/issues/{}/labels'.format(pr.repo.name, pr.number), json={
             'labels': list(set(itertools.chain.from_iterable(others)))
         })
-        assert r.ok, r.json()
+        assert r.ok, r.text
 
 class Environment:
     def __init__(self, port, db, default_crons=()):