Bats Shell Testing Patterns

What it does

When your agent uses it

• Writing unit tests for a shell script with Bats
• Testing a script's failure paths such as missing files or bad arguments
• Checking that a script behaves the same in bash, sh and dash
• Running a shell test suite in GitHub Actions

Example prompts

• “Write Bats tests for backup.sh, including a case where the source directory is missing.”
• “Add a test_helper.sh and mock the curl call in my deploy script tests.”
• “Set up a GitHub Actions workflow that runs my Bats suite on every push and pull request.”

Requirements

• Bats (Bash Automated Testing System)

Workflow steps

10 steps, taken from the first numbered list in SKILL.md.

1. 1Test one thing per test - Single responsibility principle
2. 2Use descriptive test names - Clearly states what is being tested
3. 3Clean up after tests - Always remove temporary files in teardown
4. 4Test both success and failure paths - Don't just test happy path
5. 5Mock external dependencies - Isolate unit under test
6. 6Use fixtures for complex data - Makes tests more readable
7. 7Run tests in CI/CD - Catch regressions early
8. 8Test across shell dialects - Ensure portability
9. 9Keep tests fast - Run in parallel when possible
10. 10Document complex test setup - Explain unusual patterns

What it can do on your machine

Read from SKILL.md and the folder at commit 46891e7. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • bash
  • sh

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Bats Shell Testing Patterns loads about 1.3k tokens when it runs, and up to ~3.1k if it reads all its reference files. Until then it costs about 55 tokens; SKILL.md has 224 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~55

When it runs · the whole SKILL.md, loaded when a task matches

~1.3k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~3.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from wshobson/agents at commit 46891e7, republished under its MIT licence (© wshobson). 224 words, ~1,293 tokens.

name

bats-testing-patterns

description

Master Bash Automated Testing System (Bats) for comprehensive shell script testing. Use when writing tests for shell scripts, CI/CD pipelines, or requiring test-driven development of shell utilities.

#!/usr/bin/env bats

@test "Function fails with missing file" {
    run my_function "/nonexistent/file.txt"
    [ "$status" -ne 0 ]
    [[ "$output" == *"not found"* ]]
}

@test "Function fails with invalid input" {
    run my_function ""
    [ "$status" -ne 0 ]
}

@test "Function fails with permission denied" {
    touch "$TMPDIR/readonly.txt"
    chmod 000 "$TMPDIR/readonly.txt"
    run my_function "$TMPDIR/readonly.txt"
    [ "$status" -ne 0 ]
    chmod 644 "$TMPDIR/readonly.txt"  # Cleanup
}

@test "Function provides helpful error message" {
    run my_function --invalid-option
    [ "$status" -ne 0 ]
    [[ "$output" == *"Usage:"* ]]
}

#!/usr/bin/env bats

setup() {
    # Check for required tools
    if ! command -v jq &>/dev/null; then
        skip "jq is not installed"
    fi

    export SCRIPT="${BATS_TEST_DIRNAME}/../bin/script.sh"
}

@test "JSON parsing works" {
    skip_if ! command -v jq &>/dev/null
    run my_json_parser '{"key": "value"}'
    [ "$status" -eq 0 ]
}

#!/usr/bin/env bats

@test "Script works in bash" {
    bash "${BATS_TEST_DIRNAME}/../bin/script.sh" arg1
}

@test "Script works in sh (POSIX)" {
    sh "${BATS_TEST_DIRNAME}/../bin/script.sh" arg1
}

@test "Script works in dash" {
    if command -v dash &>/dev/null; then
        dash "${BATS_TEST_DIRNAME}/../bin/script.sh" arg1
    else
        skip "dash not installed"
    fi
}

#!/usr/bin/env bats

@test "Multiple independent operations" {
    run bash -c 'for i in {1..10}; do
        my_operation "$i" &
    done
    wait'
    [ "$status" -eq 0 ]
}

@test "Concurrent file operations" {
    for i in {1..5}; do
        my_function "$TMPDIR/file$i" &
    done
    wait
    [ -f "$TMPDIR/file1" ]
    [ -f "$TMPDIR/file5" ]
}

#!/usr/bin/env bash

# Source script under test
export SCRIPT_DIR="${BATS_TEST_DIRNAME%/*}/bin"

# Common test utilities
assert_file_exists() {
    if [ ! -f "$1" ]; then
        echo "Expected file to exist: $1"
        return 1
    fi
}

assert_file_equals() {
    local file="$1"
    local expected="$2"

    if [ ! -f "$file" ]; then
        echo "File does not exist: $file"
        return 1
    fi

    local actual=$(cat "$file")
    if [ "$actual" != "$expected" ]; then
        echo "File contents do not match"
        echo "Expected: $expected"
        echo "Actual: $actual"
        return 1
    fi
}

# Create temporary test directory
setup_test_dir() {
    export TEST_DIR=$(mktemp -d)
}

cleanup_test_dir() {
    rm -rf "$TEST_DIR"
}

name: Tests

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v3

      - name: Install Bats
        run: |
          npm install --global bats

      - name: Run Tests
        run: |
          bats tests/*.bats

      - name: Run Tests with Tap Reporter
        run: |
          bats tests/*.bats --tap | tee test_output.tap

.PHONY: test test-verbose test-tap

test:
	bats tests/*.bats

test-verbose:
	bats tests/*.bats --verbose

test-tap:
	bats tests/*.bats --tap

test-parallel:
	bats tests/*.bats --parallel 4

coverage: test
	# Optional: Generate coverage reports

© wshobson, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file (references) in plugins/shell-scripting/skills/bats-testing-patterns of wshobson/agents.

• SKILL.md
• references/details.md

Open the folder on GitHubat commit 46891e7

Used in 11 other repositories

We found 31 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 11 other GitHub owners. This page covers the copy in wshobson/agents, which our catalogue first saw on October 7, 2026.

• HermeticOrmus/LibreUIUX-Claude-Codeplugins/shell-scripting/skills/bats-testing-patterns
• Microck/ordinary-claude-skillsskills_all/bats-testing-patternsskills_categorized/cicd/bats-testing-patterns+7 more
• aiskillstore/marketplaceskills/sickn33/bats-testing-patternsskills/wshobson/bats-testing-patterns
• Asymmetric-al/core.agents/skills/bats-testing-patterns.claude/skills/bats-testing-patterns+1 more
• sickn33/agentic-awesome-skillsskills/bats-testing-patternsplugins/agentic-awesome-skills/skills/bats-testing-patterns+1 more
• rmyndharis/antigravity-skillsskills/bats-testing-patterns
• agent-skills-hub/agent-skills-hubskills/bats-testing-patterns
• lingxling/awesome-skills-cnantigravity-awesome-skills/skills/bats-testing-patternsantigravity-awesome-skills/plugins/agentic-awesome-skills/skills/bats-testing-patterns+1 more
• benjaminasterA/antigravity-awesome-skillsskills/bats-testing-patterns
• henryalouf/ruflow.agents/skills/bats-testing-patterns.agents/skills/antigravity-awesome-skills/skills/bats-testing-patterns+4 more
• infometa/workbuddyskillsplugins/codebuddy-plugins-official/external_plugins/shell-scripting/skills/bats-testing-patterns