shellspec

ShellSpec provides a behavior‑driven development (BDD) style unit‑testing framework that works with dash, bash, ksh, zsh and any POSIX‑compatible shell. It supplies features such as code‑coverage reporting, mocking of commands, parameterized tests, and parallel execution, allowing developers to verify the correctness of shell scripts and libraries across diverse environments.

The tool is aimed at developers who write cross‑platform shell code and need a reliable way to test functionality on Linux, macOS, BSD variants, Solaris and Windows environments (via git‑bash, Cygwin, MSYS, BusyBox). Its command‑line interface offers practical utilities for running and managing test suites, and the syntax is designed to be simple yet expressive for shell scripting.

Since its initial release in 2019, ShellSpec has reached a stable maturity level and is distributed with a Docker image, continuous‑integration badges for many platforms, and open‑source licensing. It is positioned as a modern alternative to ad‑hoc shell testing approaches, emphasizing reproducibility and comprehensive test coverage.