[CI] Use github's graphQL to query review state directly

ci/ci/github.py

@@ -486,27 +486,36 @@ async def _update_last_known_github_status(self, gh):
  self.target_branch.state_changed = True
 
  async def _update_github_review_state(self, gh):
- latest_state_by_login = {}
- async for review in gh.getiter(
- f'/repos/{self.target_branch.branch.repo.short_str()}/pulls/{self.number}/reviews'
- ):
- login = review['user']['login']
- state = review['state']
- # reviews is chronological, so later ones are newer statuses
- if state != 'COMMENTED':
- latest_state_by_login[login] = state
-
- review_state = 'pending'
- for login, state in latest_state_by_login.items():
- if state == 'CHANGES_REQUESTED':
- review_state = 'changes_requested'
- break
- if state == 'APPROVED':
- review_state = 'approved'
- else:
- assert state in ('DISMISSED', 'COMMENTED', 'PENDING'), state
+ review_state_query = f"""
+ query {{
+ repository(owner: "{self.target_branch.branch.repo.owner}", name: "{self.target_branch.branch.repo.name}") {{
+ pullRequest(number: {self.number}) {{
+ reviewDecision
+ }}
+ }}
+ }}
+ """
+
+ response = await gh.post('/graphql', data={'query': review_state_query})
+ review_decision = response['data']['repository']['pullRequest']['reviewDecision']
+
+ if review_decision == 'APPROVED':
+ review_state = 'approved'
+ elif review_decision == 'CHANGES_REQUESTED':
+ review_state = 'changes_requested'
+ elif review_decision == 'REVIEW_REQUIRED':
+ review_state = 'pending'
+ elif review_decision is None:
+ # This probably means the repo has no "required reviews" configuration. But CI shouldn't merge without
+ # at least one approval, so we'll treat this as "pending":
+ review_state = 'pending'
+ else:
+ # Should be impossible, per https://docs.github.com/en/graphql/reference/enums#pullrequestreviewdecision
+ log.error(f'{self.short_str()}: unexpected review decision from github: {review_decision}')
+ review_state = 'pending'
 
  if review_state != self.review_state:
+ log.info(f'{self.short_str()}: review state changing from {self.review_state} => {review_state}')
  self.set_review_state(review_state)
  self.target_branch.state_changed = True