#!/usr/bin/env bash

# https://www.tldp.org/LDP/abs/html/options.html#AEN19601

# https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html

set -u -e -E -o pipefail

BOLD='printf \e[1m'

RESET_STYLES='printf \e[0m'

LIGHT_CYAN='printf \e[96m'

LIGHT_MAGENTA='printf \e[95m'

GREEN='printf \e[32m'

RED='printf \e[31m'

BASEDIR=$(dirname "$0")

BASEDIR=`(cd $BASEDIR; pwd)`

PR_NUMBER=0

PUSH_UPSTREAM=1

FORCE=0

while [[ $# -gt 0 ]]

do

key="$1"

case $key in

--dryrun)

PUSH_UPSTREAM=0

shift # past argument

;;

--force)

FORCE=1

shift # past argument

;;

*) # unknown option

PR_NUMBER="$1" # save it in an array for later

shift # past argument

;;

esac

done

if [ "$PR_NUMBER" -eq 0 ]; then

echo "Merge github PR into the target branches if status is green"

echo

echo "$0 PR_NUMBER [--dryrun] [--force]"

echo

echo --dryrun Performs all operations but does not push the merge back to git@github.com:angular/angular.git.

echo --force Continues even if PR status is not green.

exit 0

fi

if [ -z ${TOKEN:-''} ]; then

$RED

echo "############################################################"

echo "############################################################"

echo "WARNING: you should set the TOKEN variable to a github token"

echo "############################################################"

echo "############################################################"

$RESET_STYLES

GH_AUTH=""

else

GH_AUTH="Authorization: token $TOKEN"

fi

PULL_JSON=`curl -H "$GH_AUTH" -s https://api.github.com/repos/angular/angular/pulls/$PR_NUMBER`

PR_SHA_COUNT=`node $BASEDIR/utils/json_extract.js commits <<< """$PULL_JSON"""`

STATUS_JSON_URL=`node $BASEDIR/utils/json_extract.js _links.statuses.href <<< """$PULL_JSON"""`

STATUS=`curl -H "$GH_AUTH" -s $STATUS_JSON_URL | node $BASEDIR/utils/json_extract.js description | cut -d '|' -f1`

PR_LABELS=`curl -H "$GH_AUTH" -s https://api.github.com/repos/angular/angular/issues/$PR_NUMBER/labels`

PR_ACTION=`echo "$PR_LABELS" | node $BASEDIR/utils/json_extract.js "name=^PR action:"`

PR_TARGET=`echo "$PR_LABELS" | node $BASEDIR/utils/json_extract.js "name=^PR target:"`

PR_CLA=`echo "$PR_LABELS" | node $BASEDIR/utils/json_extract.js "name=^cla"`

MASTER_BRANCH='master'

if [[ ! "$PR_ACTION" =~ "PR action: merge" ]]; then

$RED

echo The PR is missing 'PR action: merge(-assistance)' label, found: $PR_ACTION

$RESET_STYLES

exit 1

fi

if [[ "$PR_CLA" != "cla: yes" ]]; then

$RED

echo The PR is missing 'cla: Yes' label, found: $PR_CLA

$RESET_STYLES

exit 1

fi

if [[ "$STATUS" != "All checks passed!" ]]; then

echo PR $PR_NUMBER is failing with: $STATUS

if [[ $FORCE == 1 ]]; then

$BOLD

$LIGHT_MAGENTA

echo FORCING: --force flag used to ignore PR status.

$RESET_STYLES

else

echo Exiting...

exit 1

fi

fi

if [[ $PR_TARGET == "PR target: master & patch" ]]; then

MERGE_MASTER=1

MERGE_PATCH=1

elif [[ $PR_TARGET == "PR target: master-only" ]]; then

MERGE_MASTER=1

MERGE_PATCH=0

elif [[ $PR_TARGET == "PR target: patch-only" ]]; then

MERGE_MASTER=0

MERGE_PATCH=1

else

$RED

echo "Unknown PR target format: $PR_TARGET"

$RESET_STYLES

exit 1;

fi

CURRENT_BRANCH=`git rev-parse --abbrev-ref HEAD`

PATCH_BRANCH=`git ls-remote --heads git@github.com:angular/angular.git | grep -E 'refs\/heads\/[0-9]+\.[0-9]+\.x' | cut -d '/' -f3 | sort -r | head -n1`

CHECKOUT_MASTER="git checkout merge_pr_master"

CHECKOUT_PATCH="git checkout merge_pr_patch"

RESTORE_BRANCH="git checkout $CURRENT_BRANCH"

FETCH_PR="git fetch git@github.com:angular/angular.git pull/$PR_NUMBER/head:merge_pr heads/$MASTER_BRANCH:merge_pr_master heads/$PATCH_BRANCH:merge_pr_patch -f"

BASE_PR="git checkout merge_pr~$PR_SHA_COUNT -B merge_pr_base"

SQUASH_PR="git rebase --autosquash --interactive merge_pr_base merge_pr"

REWRITE_MESSAGE="git filter-branch -f --msg-filter \"$BASEDIR/utils/github_closes.js $PR_NUMBER\" merge_pr_base..merge_pr"

PUSH_BRANCHES="git push git@github.com:angular/angular.git merge_pr_master:$MASTER_BRANCH merge_pr_patch:$PATCH_BRANCH"

CHERRY_PICK_PR="git cherry-pick merge_pr_base..merge_pr"

# Checks that each PR branch to be merged upstream contains SHAs of commits that significantly changed our CI infrastructure.

#

# This check is used to enforce that we don't merge PRs that have not been rebased recently and could result in merging

# of non-approved or otherwise bad changes.

REQUIRED_BASE_SHA_MASTER="3fba6eff79a9b50909199eaa4ebf754c1c4adba6" # pullapprove => CODEOWNERS migration

REQUIRED_BASE_SHA_PATCH="e3853e842ea5c10fafbc310a76a4a7f47ed8c65e" # pullapprove => CODEOWNERS migration

if [[ $MERGE_MASTER == 1 ]]; then

REQUIRED_BASE_SHA="$REQUIRED_BASE_SHA_MASTER"

# check patch only if patch-only PR

elif [[ $MERGE_PATCH == 1 ]]; then

REQUIRED_BASE_SHA="$REQUIRED_BASE_SHA_PATCH"

fi

CHECK_IF_PR_REBASED="git branch --quiet merge_pr --contains $REQUIRED_BASE_SHA"

$BOLD

$LIGHT_CYAN

echo "======================"

echo "GitHub Merge PR Steps"

echo "======================"

echo " $FETCH_PR"

echo " $BASE_PR"

echo " $CHECK_IF_PR_REBASED"

echo " $SQUASH_PR"

echo " $REWRITE_MESSAGE"

if [[ $MERGE_MASTER == 1 ]]; then

echo " $CHECKOUT_MASTER && $CHERRY_PICK_PR"

fi

if [[ $MERGE_PATCH == 1 ]]; then

echo " $CHECKOUT_PATCH && $CHERRY_PICK_PR"

fi

echo " $PUSH_BRANCHES"

echo " $RESTORE_BRANCH"

echo "----------------------"

$RESET_STYLES

$BOLD

echo ""

echo ">>> Fetch PR: $FETCH_PR"

$RESET_STYLES

$FETCH_PR

$BOLD

echo ""

echo ">>> Mark base: $BASE_PR"

$RESET_STYLES

$BASE_PR

$BOLD

echo ""

echo ">>> Check if PR rebased: $CHECK_IF_PR_REBASED"

$RESET_STYLES

if [[ $($CHECK_IF_PR_REBASED) != "" ]]; then

$GREEN

echo "The PR is sufficiently rebased!"

$RESET_STYLES

else

$RED

echo ""

echo ""

echo "Failed to merge pull request #${PR_NUMBER} because it hasn't been rebased recently and could be bypassing new or updated CI checks!"

echo ""

echo "Please rebase the PR and try again."

echo ""|

$RESET_STYLES

$RESTORE_BRANCH

exit 1

fi

$BOLD

echo ""

echo ">>> Autosquash: $SQUASH_PR"

$RESET_STYLES

GIT_EDITOR=echo $SQUASH_PR

$BOLD

echo ""

echo ">>> Rewrite message: $REWRITE_MESSAGE"

# Next line should work, but it errors, hence copy paste the command.

# $REWRITE_MESSAGE

$RESET_STYLES

git filter-branch -f --msg-filter "$BASEDIR/utils/github_closes.js $PR_NUMBER" merge_pr_base..merge_pr

if [[ $MERGE_MASTER == 1 ]]; then

$BOLD

echo

echo ">>> Cherry pick to master: $CHECKOUT_MASTER && $CHERRY_PICK_PR"

$RESET_STYLES

$CHECKOUT_MASTER

$CHERRY_PICK_PR

fi

if [[ $MERGE_PATCH == 1 ]]; then

$BOLD

echo

echo ">>> Cherry pick to patch: $CHECKOUT_PATCH && $CHERRY_PICK_PR"

$RESET_STYLES

$CHECKOUT_PATCH

$CHERRY_PICK_PR

fi

$RESTORE_BRANCH

if [[ $PUSH_UPSTREAM == 1 ]]; then

$BOLD

echo

echo ">>> Push branches to angular repo"

$RESET_STYLES

$PUSH_BRANCHES

fi

$BOLD

$GREEN

echo

echo ">>>>>> SUCCESS <<<<<< PR#$PR_NUMBER merged."

$RESET_STYLES