Validate bpo issue number

bedevere/__main__.py

@@ -37,7 +37,7 @@ async def main(request):
                                       cache=cache)
             # Give GitHub some time to reach internal consistency.
             await asyncio.sleep(1)
-            await router.dispatch(event, gh)
+            await router.dispatch(event, gh, session=session)
         try:
             print('GH requests remaining:', gh.rate_limit.remaining)
         except AttributeError:

bedevere/bpo.py

@@ -21,35 +21,33 @@
 SKIP_ISSUE_LABEL = util.skip_label("issue")
 STATUS_CONTEXT = "bedevere/issue-number"
 # Try to keep descriptions at or below 50 characters, else GitHub's CSS will truncate it.
-_FAILURE_DESCRIPTION = 'No issue # in title or "skip issue" label found'
-_FAILURE_URL = "https://devguide.python.org/pullrequest/#submitting"
-FAILURE_STATUS = util.create_status(STATUS_CONTEXT, util.StatusState.FAILURE,
-                                    description=_FAILURE_DESCRIPTION,
-                                    target_url=_FAILURE_URL)
-del _FAILURE_DESCRIPTION
-del _FAILURE_URL
 SKIP_ISSUE_STATUS = util.create_status(STATUS_CONTEXT, util.StatusState.SUCCESS,
                                        description="Issue report skipped")
 
 
 @router.register("pull_request", action="opened")
 @router.register("pull_request", action="synchronize")
 @router.register("pull_request", action="reopened")
-async def set_status(event, gh, *args, **kwargs):
+async def set_status(event, gh, session=None, *args, **kwargs):
     """Set the issue number status on the pull request."""
     issue_number_found = ISSUE_RE.search(event.data["pull_request"]["title"])
     if not issue_number_found:
         issue = await util.issue_for_PR(gh, event.data["pull_request"])
-        status = SKIP_ISSUE_STATUS if util.skip("issue", issue) else FAILURE_STATUS
+        status = (SKIP_ISSUE_STATUS if util.skip("issue", issue)
+                                    else create_failure_status_no_issue())
     else:
-        if "body" in event.data["pull_request"]:
-            body = event.data["pull_request"]["body"] or ""
-            if not body or CLOSING_TAG not in body:
-                issue_number = issue_number_found.group("issue")
-                new_body = BODY.format(body=body, issue_number=issue_number)
-                body_data = {"body": new_body}
-                await gh.patch(event.data["pull_request"]["url"], data=body_data)
-        status = create_success_status(issue_number_found)
+        issue_number = issue_number_found.group("issue")
+        issue_number_on_bpo = await _validate_issue_number(issue_number, session=session)
+        if issue_number_on_bpo:
+            if "body" in event.data["pull_request"]:
+                body = event.data["pull_request"]["body"] or ""
+                if not body or CLOSING_TAG not in body:
+                    new_body = BODY.format(body=body, issue_number=issue_number)
+                    body_data = {"body": new_body}
+                    await gh.patch(event.data["pull_request"]["url"], data=body_data)
+            status = create_success_status(issue_number)
+        else:
+            status = create_failure_status_issue_not_on_bpo(issue_number)
     await util.post_status(gh, event, status)
 
 
@@ -68,7 +66,7 @@ async def new_label(event, gh, *args, **kwargs):
         issue_number_found = ISSUE_RE.search(
             event.data["pull_request"]["title"])
         if issue_number_found:
-            status = create_success_status(issue_number_found)
+            status = create_success_status(issue_number_found.group("issue"))
         else:
             status = SKIP_ISSUE_STATUS
         await util.post_status(gh, event, status)
@@ -104,15 +102,32 @@ async def hyperlink_bpo_text(event, gh, *args, **kwargs):
             await gh.patch(event.data[event_name][body_location], data=body_data)
 
 
-def create_success_status(found_issue):
+def create_success_status(issue_number):
     """Create a success status for when an issue number was found in the title."""
-    issue_number = found_issue.group("issue")
     url = f"https://bugs.python.org/issue{issue_number}"
     return util.create_status(STATUS_CONTEXT, util.StatusState.SUCCESS,
                               description=f"Issue number {issue_number} found",
                               target_url=url)
 
 
+def create_failure_status_issue_not_on_bpo(issue_number):
+    """Create a failure status for when an issue does not exist on the bug tracker."""
+    description = f"Issue #{issue_number} not found on bugs.python.org"
+    url = f"https://bugs.python.org/issue{issue_number}"
+    return util.create_status(STATUS_CONTEXT, util.StatusState.FAILURE,
+                              description=description,
+                              target_url=url)
+
+
+def create_failure_status_no_issue():
+    """Create a failure status for when no issue number was found in the title."""
+    description = 'No issue # in title or "skip issue" label found'
+    url = "https://devguide.python.org/pullrequest/#submitting"
+    return util.create_status(STATUS_CONTEXT, util.StatusState.FAILURE,
+                              description=description,
+                              target_url=url)
+
+
 def check_hyperlink(match):
     """The span checking of regex matches takes care of cases like bpo-123 [bpo-123]…"""
     issue = match.group("issue")
@@ -155,3 +170,10 @@ def create_hyperlink_in_comment_body(body):
             leftover_body = leftover_body[presence:]
     new_body = new_body + leftover_body
     return new_body
+
+
+async def _validate_issue_number(issue_number, session):
+    """Make sure the issue number exists on bugs.python.org."""
+    url = f"https://bugs.python.org/issue{issue_number}"
+    async with session.head(url) as res:
+        return res.status != 404

dev-requirements.txt

@@ -1,4 +1,5 @@
 -r requirements.txt
+asynctest==0.13.0
 pytest==5.0.1
 pytest-asyncio==0.10.0
 pytest-aiohttp==0.3.0