Script for release notes, that check if last commit was merge, then join all messages; otherwise takes just last commit message

get_commit_mesages.sh

#!/bin/bash

# Check if the last commit is a merge commit
# by getting commit parents (for merge there would be two parents)
if [[ $(git log --format=%P -n 1 | wc -w) -gt 1 ]]; then
    LAST_COMMIT=$(git rev-parse HEAD)
    MERGE_HASHES=$(git log --pretty=format:%H $LAST_COMMIT~...$LAST_COMMIT)

    COMMIT_MESSAGE=""
    # Loop through each merge commit and extract messages
    for HASH in $MERGE_HASHES; do
        # Skip the merge commit hash
        if [[ "$HASH" == "$LAST_COMMIT" ]]; then
            continue
        fi

        # Extract commit message for each parent commit
        MESSAGE=$(git log --format=%B -n 1 $HASH)

        # Append the commit message to the overall message
        COMMIT_MESSAGE="$COMMIT_MESSAGE$MESSAGE\n"
    done

    # Output the combined commit messages
    echo -e "$COMMIT_MESSAGE"
else
    # If it's not a merge commit, get the message of the last commit
    COMMIT_MESSAGE=$(git log --format=%B -n 1)
    echo "$COMMIT_MESSAGE"
fi