Unit testing Bash scripts

There is actually a shunit2, an xUnit based unit test framework for Bourne based shell scripts. I haven't used it myself, but it might be worth checking out.

Similar questions have been asked before:

• Unit Testing for Shell Scripts
• Test Anything Protocol in Shell Scripts

TAP-compliant Bash testing: Bash Automated Testing System

TAP, the Test Anything Protocol, is a simple text-based interface between testing modules in a test harness. TAP started life as part of the test harness for Perl but now has implementations in C, C++, Python, PHP, Perl, Java, JavaScript, and others.

bats-core

I got the following answer from a discussion group:

it's possible to import (include, whatever) a procedure (function, whatever it's named) from an external file. That's the key to writing a testing script: you break up your script into independent procedures that can then be imported into both your running script and your testing script, and then you have your running script be as simple as possible.

This method is like dependency injection for scripts and sounds reasonable. Avoiding Bash scripts and using more testable and less obscure language is preferable.