shell-tdd

name	shell-tdd
description	Shell-based TDD test harness patterns — pass/fail counters, common assertions, set -e gotchas, and exit code conventions for bash test scripts
type	reference
version	1.0.0
category	development
capabilities	["shell_test_harness","bash_assertions","tdd_shell_patterns"]
tools	["Bash","Read","Edit"]
related_skills	["tdd-obra","gitignore-scaffold","testing-tdd-london"]
requires	[]
see_also	[]
tags	[]

Shell TDD Test Harness

Quick Start

Shell TDD scripts follow a simple pattern: counter functions, if-block assertions, and exit $FAIL for CI integration. The critical rule is never use (( var++ )) with set -e — use var=$((var + 1)) instead.

Template

#!/usr/bin/env bash
set -euo pipefail

REPO_ROOT="$(git -C "$(dirname "$0")" rev-parse --show-toplevel)"
PASS=0
FAIL=0

pass() { PASS=$((PASS + 1)); echo "  PASS: $1"; }
fail() { FAIL=$((FAIL + 1)); echo "  FAIL: $1"; }

echo "=== Suite: <name> ==="

# --- AC1: <description> ---
echo ""
echo "--- AC1: <description> ---"

if <check>; then
    pass "<what passed>"
else
    fail "<what failed>"
fi

# --- Summary ---
echo ""
echo "=== Results: $PASS passed, $FAIL failed ==="
exit $FAIL

Common Assertions

# File exists
if [ -f  ];  pass ;  fail ; 


 [ -d  ];  pass ;  fail ; 


 grep -q  ;  pass ;  fail ; 


 git check-ignore -q ;  pass ;  fail ; 


 command_here;  pass ;  fail ; 


 [  =  ];  pass ;  fail ; 


 [ -s  ];  pass ;  fail ; 


 [ -n  ];  pass ;  fail ;