Function gitBranchCreationPoint

build-system/common/git.js:23–31

* Returns the commit at which the current PR branch was forked off of the main * branch. During CI, there is an additional merge commit, so we must pick the * first of the boundary commits (prefixed with a -) returned by git rev-list. * On local branches, this is merge base of the current branch

()

 * @return {string}
 */
function gitBranchCreationPoint() {
  if (isPullRequestBuild()) {
    const prSha = ciPullRequestSha();
    return getStdout(
      `git rev-list --boundary ${prSha}...origin/main | grep "^-" | head -n 1 | cut -c2-`
    ).trim();
  }
  return gitMergeBaseLocalMain();
}

/**
 * Returns the main branch parent of the merge commit (current HEAD) during CI