Testing 'bash' scripts with 'bashunit'

I have used the “Bourne Again Shell” (bash) for years now to automate various tasks. One thing that has bothered me for a long time is not having a good way to test my scripts. Recently, I became aware of “bashunit” while setting up “neovim” as my IDE.

Setup “bashunit”

If you use a Mac with “Homebrew” as your favorite package manager, you can install “bashunit” with the following brew command. See the “bashunit” documentation for other installation options.

brew install bashunit

Writing and running the first test

Writing tests with “bashunit” does not require a complex setup, as the bashunit file is self-contained. First, let’s create a sample ‘bash’ script.

vim hello-world.sh

#!/bin/bash

function hello_world() {
  echo "hello world"
}

hello_world

Next, let’s write our first test with the name given below. I built the set_up() function in a way that requires you to name your test files consistently. If you choose to use a different naming scheme, make sure to change the set_up() function accordingly and look for the “bashunit” documentation about naming test files. For more test examples written with “bashunit” head over to the project’s documentation at https://bashunit.typeddevs.com/examples.

• Script file: hello-world.sh
• Test file: hello-world_test.sh

vim hello-world_test.sh

#!/bin/bash

function set_up() {
  ROOT_DIR="$(dirname "${BASH_SOURCE[0]}")"
  FILE_NAME="$(basename "${BASH_SOURCE[0]%_test.sh}").sh"
  SCRIPT="${ROOT_DIR}/${FILE_NAME}"
}

function test_hello_world() {
  assert_equals "hello world" "$($SCRIPT)"
}

Thanks for reading!