[extract-inputs] API rate limit exceeded for "search"

[mikeharder]

Discussion: https://teams.microsoft.com/l/message/19:Xt2F9HOih2CBPF2nvhz3Y5SRC4-jMj2bhVFJAiE0S4M1@thread.skype/1753831371132?tenantId=72f988bf-86f1-41af-91ab-2d7cd011db47&groupId=3e17dcb0-4257-4a30-b843-77f47f1d4121&parentMessageId=1753831371132&teamName=Azure%20SDK&channelName=Descend%20from%20the%20Alps&createdTime=1753831371132&ngc=true

https://github.com/Azure/azure-rest-api-specs/actions/runs/16580144702/job/46894092390

SHA: 0f9cbae

PR: #36252

I spent a few hours investigating, but never completely understood. Two questions:

1. For this specific run, why did we need to call the search API for this commit SHA? If the triggering event was workflow_run:pull_request_target, why isnt' the SHA associated with a PR now?

   • Answer: Because the PR was closed immediately before the WF ran.

2. Why are we calling the search API often enough to hit the rate limit? It should only be called in rare cases where the main API failed.

   • Answer: Rate limit is 30 calls per minute. With the number of checks and status updates we run, we could hit this on a single closed PR.

Possible Solutions

Use the GH actions cache to avoid repeated calls to search API:

let pr = getCache(sha);

if (pr) {
  const commits = getCommits(pr); // higher rate limit than search
  if (commits.includes(pr)) {
    return pr;
  }
}

// cache was empty or stale (cached PR no longer contains commit)
pr = callSearchApi(sha);
if (pr) {
  setCache(sha, pr);
}

return pr; // may be NaN

The GH APIs are asymmetric, in that "get-commits-for-pr" is simple and always works, but "get-pr-for-commit" is super complex

limited to 250 commits, but assuming it's the 250 most recent, it should always include the recent triggering commit:

https://docs.github.com/en/rest/pulls/pulls?apiVersion=2022-11-28#list-commits-on-a-pull-request

And, we just fallback to search API if cache may be invalid.

We should be able to use cache from JS, but we need to install the package:

https://github.com/actions/toolkit/tree/main/packages/cache

@actions/artifact as part of the github-script · Issue #395 · actions/github-script

[mikeharder]

subsequent changes likely make this a non-issue, or would require a new investigation if we still hit the rate limit