m() {
  # mocha default path is test/mocha.opts
  file=$(readlink -f $1)
  [ -f "test/mocha.opts" ] && (mocha $file)
  [ -f "../../mocha.opts" ] && (cd ../../../ && mocha $file)
  [ -f "../../../mocha.opts" ] && (cd ../../../../ && mocha $file)
  [ -f "../../../../mocha.opts" ] && (cd ../../../../../ && mocha $file)
  [ -f "../../../../../mocha.opts" ] && (cd ../../../../../../ && mocha $file)
  [ -f "../../../../../../mocha.opts" ] && (cd ../../../../../../../ && mocha $file)
}