Command substitution issue?

bats-stub-issue.sh

# This doesn't work together with bats stub as defined in ruby-build
compute_sha2() {
  if type shasum &>/dev/null; then
    local output="$(shasum -a 256 -b)"
    echo "${output% *}"
  elif type openssl &>/dev/null; then
    local output="$(openssl dgst -sha256)"
    echo "${output##* }"
  elif type sha256sum &>/dev/null; then
    local output="$(sha256sum --quiet)"
    echo "${output% *}"
  else
    return 1
  fi
}


# This works in bats when `shasum` is stubbed, but breaks against
# the real binary because the output is "noisy"...
compute_sha2() {
  if type shasum &>/dev/null; then
    shasum -a 256 -b
  elif type openssl &>/dev/null; then
    local output="$(openssl dgst -sha256)"
    echo "${output##* }"
  elif type sha256sum &>/dev/null; then
    local output="$(sha256sum --quiet)"
    echo "${output% *}"
  else
    return 1
  fi
}