A couple of ways to look up a GitHub pull request via the v4 GraphQL API

github-graphql-examples.md

GitHub GraphQL API v4 Examples

Here are two queries that look up information about a pull request via GitHub's GraphQL API v4. The first looks up a pull request by number, the second looks up a pull request by ref (i.e. commit hash, branch name, tag name).

Why tho

While it is trivial to use the RESTful v3 API to look up a pull request by number, the GraphQL API is the only way to do the same thing for an arbitrary reference in a single HTTP request.

These took a bit of trial and error in the GitHub's GraphQL Explorer and various support threads to get right, so I'm putting them up here for posterity.

query-pull-request-by-number.graphql

query ($repoOwner: String!, $repoName: String!, $pullRequestID: Int!) {
  repository(owner: $repoOwner, name: $repoName) {
    pullRequest(number: $pullRequestID) {
      author {
        login
      }
      baseRefOid
      headRefName
      headRefOid
      mergeable
      reviewDecision
      state
      title
    }
  }
}

# Example variables
#
# {
#   "repoOwner": "mccutchen",
#   "repoName": "go-httpbin",
#   "pullRequestID": 49
# }

query-pull-request-by-ref.graphql

query ($repoOwner: String!, $repoName: String!, $ref: String!) {
  repository(name: $repoName, owner: $repoOwner) {
    commit: object(expression: $ref) {
      ... on Commit {
        associatedPullRequests(first: 100) {
          nodes {
            author {
              login
            }
            baseRefOid
            headRefName
            headRefOid
            mergeable
            number
            reviewDecision
            state
            title
          }
        }
      }
    }
  }
}

# Example variables
#
# {
#   "repoOwner": "mccutchen",
#   "repoName": "go-httpbin",
#   "ref": "8f5ca46"
# }