currentBranch method
Implementation
Future<BranchReference> currentBranch() async {
var pr = await runCommand(
const ['rev-parse', '--verify', '--symbolic-full-name', 'HEAD'],
);
pr = await runCommand(
['show-ref', '--verify', (pr.stdout as String).trim()],
);
return CommitReference.fromShowRefOutput(pr.stdout as String)
.single
.toBranchReference();
}