A script to figure out if a release commit was part of a merge (i.e. part of the entire merged branch or current HEAD commit)

release-check.sh

#!/bin/bash
#
# Script to publish apps to the Play Store in case a release is discovered
#

SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
. "${SCRIPT_DIR}/../inc.functions.sh"

# Constants
SECRET_FILE=config/play-publishing-api.json

# Checks
[[ -f ${SECRET_FILE} ]] || die "App update requires credentials at '${SECRET_FILE}'"

# Functions
function is_release_commit {
    commit_message=$(git log --oneline --format=%B -n 1 ${1} | head -n 1)
    if [[ "${commit_message}" == "Release version "* ]] ; then
        return 0
    else
        return 1
    fi
}

# Let's roll
git_head_commit=$(git rev-parse HEAD)
git_last_merge_commit=$(git log -1 --format=%H --merges)

if [[ ${git_head_commit} == ${git_last_merge_commit} ]] ; then
    # HEAD is a merge commit, check commits on merged branch for a release commit by
    # finding common ancestor and by iterating all commits from that branch
    git_branch_parent_commits=( $(git log -1 --merges --pretty=format:%P) )
    git_branch_merge_base_commit=$(git merge-base --all ${git_branch_parent_commits[0]} ${git_branch_parent_commits[1]})

    for commit in $(git log --pretty=%H ${git_branch_merge_base_commit}..${git_branch_parent_commits[1]}) ; do
        if is_release_commit ${commit} ; then
            approve "Release commit found in branch at ${commit}, publishing app..."
            # Checkout release commit and build exactly that...
            git checkout ${commit}
            ./gradlew publishReleaseBundle --artifact-dir mobile/build/outputs/bundle/release
            git checkout ${git_head_commit}
            exit 0
        fi
    done
elif is_release_commit ${git_head_commit} ; then
    approve "Release commit found at HEAD (${git_head_commit}), publishing app..."
    ./gradlew publishReleaseBundle --artifact-dir mobile/build/outputs/bundle/release
    exit 0
fi

warn "No release commit, skipping..."