get_codebuild_pull_request.sh

#!/usr/bin/env bash

set -eu

if [ -z "${CODEBUILD_WEBHOOK_EVENT:-}" ]; then
  repo=$(echo "${CODEBUILD_SOURCE_REPO_URL}" | sed -E "s|https://github\.com/(.*)$|\1|" | sed -E "s|\.git$||")
  # https://docs.github.com/en/rest/reference/repos#list-pull-requests-associated-with-a-commit
  body=$(curl \
  -H "Authorization: token $GITHUB_TOKEN" \
  -H "Accept: application/vnd.github.groot-preview+json" \
  "https://api.github.com/repos/$repo/commits/$CODEBUILD_SOURCE_VERSION/pulls")
  if [ "$(echo "$body" | jq ". | length")" -eq 0 ]; then
    echo "no pull requests"
    exit 0
  else
    pr_number=$(echo "$body" | jq ".[0].number")
    base=$(echo "$body" | jq -r ".[0].base.ref")
    head=$(echo "$body" | jq -r ".[0].head.ref")
    echo "$pr_number"
    echo "$base"
    echo "$head"
  fi
fi