tools: add util scripts to land and rebase PRs

PR-URL: #54656
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: LiviaMedeiros <livia@cirno.name>

tools/actions/merge.sh

@@ -0,0 +1,62 @@
+#!/bin/sh
+
+# Requires [gh](https://cli.github.com/), [jq](https://jqlang.github.io), git, and grep. Also awk if you pass a URL.
+
+# This script can be used to "purple-merge" PRs that are supposed to land as a single commit, using the "Squash and Merge" feature of GitHub.
+# To land a PR with this tool:
+# 1. Run `git node land <pr-id-or-url> --fixupAll`
+# 2. Copy the hash of the commit at the top of the PR branch.
+# 3. Run `tools/actions/merge.sh <pr-id-or-url> <commit-hash>`.
+
+set -xe
+
+pr=$1
+commit_head=$2
+shift 2 || { echo "Expected two arguments"; exit 1; }
+
+OWNER=nodejs
+REPOSITORY=node
+
+if expr "X$pr" : 'Xhttps://github.com/[^/]\{1,\}/[^/]\{1,\}/pull/[0-9]\{1,\}' >/dev/null; then
+  OWNER="$(echo "$pr" | awk 'BEGIN { FS = "/" } ; { print $4 }')"
+  REPOSITORY="$(echo "$pr" | awk 'BEGIN { FS = "/" } ; { print $5 }')"
+  pr="$(echo "$pr" | awk 'BEGIN { FS = "/" } ; { print $7 }')"
+elif ! expr "X$pr" : 'X[0-9]\{1,\}' >/dev/null; then
+  echo "The first argument should be the PR ID or URL"
+fi
+
+git log -1 HEAD  --pretty='format:%B' | git interpret-trailers --parse --no-divider | \
+  grep -q -x "^PR-URL: https://github.com/$OWNER/$REPOSITORY/pull/$pr$" || {
+    echo "Invalid PR-URL trailer"
+    exit 1
+  }
+git log -1 HEAD^ --pretty='format:%B' | git interpret-trailers --parse --no-divider | \
+  grep -q -x "^PR-URL: https://github.com/$OWNER/$REPOSITORY/pull/$pr$" && {
+    echo "Refuse to squash and merge a PR landing in more than one commit"
+    exit 1
+  }
+
+commit_title=$(git log -1 --pretty='format:%s')
+commit_body=$(git log -1 --pretty='format:%b')
+
+jq -n \
+    --arg title "${commit_title}" \
+    --arg body "${commit_body}" \
+    --arg head "${commit_head}" \
+    '{merge_method:"squash",commit_title:$title,commit_message:$body,sha:$head}' > output.json
+cat output.json
+if ! gh api -X PUT "repos/${OWNER}/${REPOSITORY}/pulls/${pr}/merge" --input output.json > output; then
+    cat output
+    echo "Failed to merge $pr"
+    rm output output.json
+    exit 1
+fi
+cat output
+if ! commits="$(jq -r 'if .merged then .sha else error("not merged") end' < output)"; then
+    echo "Failed to merge $pr"
+    rm output output.json
+    exit 1
+fi
+rm output.json output
+
+gh pr comment "$pr" --repo "$OWNER/$REPOSITORY" --body "Landed in $commits"

tools/actions/rebase.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+set -xe
+
+# shellcheck disable=SC2016
+gh api graphql -F "prID=$(gh pr view "$1" --json id --jq .id || true)" -f query='
+mutation RebasePR($prID: ID!) {
+    updatePullRequestBranch(input:{pullRequestId:$prID,updateMethod:REBASE}) {
+        clientMutationId
+    }
+}'