code: function(done) {
      debug("Running `git branch` command...");
      exec(
        "git branch --no-color --verbose --no-abbrev --contains HEAD",
        function(err, stdout) {
          var status = {},
            matches = /^\* (.+?)\s+([0-9a-f]{8,})/im.exec(stdout);
  
          if (err || !matches) {
            done(err || "branch not found");
          } else if (matches[1].indexOf(" ") >= 0) {
            done("not a branch tip: " + matches[2]);
          } else {
            status.branch = matches[1];
            status.head = matches[2];
            exec("git diff --quiet HEAD", function(err) {
              status.changed = !!err;
              done(null, status);
            });
          }
        }
      );
    }
docs: git helper.