Bats: Bash Automated Testing System
Bats is a TAP-compliant testing framework
for Bash. It provides a simple way to verify that the UNIX programs
you write behave as expected.
A Bats test file is a Bash script with special syntax for defining
test cases. Under the hood, each test case is just a function with a
description.
#!/usr/bin/env bats
@test "addition using bc" {
result="$(echo 2+2