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.
Bats is most useful when testing software written in Bash, but you can use
it to test any UNIX program.