Returns the number of commits behind and ahead between two branches

[Florent SEVESTRE]

Hi guys,
for a small project I'm working on, using GitElephant, I want to display the number of commits behind and ahead between the current branch and the origin one.

For now, I do something like this :

    private function getAheadBehindCommitsCount(Branch $branch)
    {
        $branchName = $branch->getName();

        try {
            $output = $branch->getRepository()
                ->getCaller()
                ->execute("rev-list --left-right --count origin/$branchName...$branchName")
                ->getOutput()
            ;

            preg_match_all('!\d+!', $output, $matches);
        } catch (\RuntimeException $e) {
            return ['-', '-'];
        }

        return $matches[0];
    }

I thought that this feature could be added to this library.
This could be changed by providing two branch objects instead of one (but what about the origin?) / or the branch names directly.

To be honest, I have found the Git command on stackoverflow, I don't know if it is the best way to retrieve this informations, I'm not a Git expert.

Is this kind of feature in the scope of this library ?

[Tim Bernhard]

Sure! Feel free to open a PR