mcpbeat Sign in

Bats Testing Patterns Agent Skill

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.

3k tokens
context cost
the whole folder, loaded on every use
2
files
instructions only
0
copies elsewhere
how many repositories repackaged it
38452
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/wshobson/agents --skill bats-testing-patterns

The instruction itself

13 sections, as written by the author

Bats Testing Patterns

Comprehensive guidance for writing comprehensive unit tests for shell scripts using Bats (Bash Automated Testing System), including test patterns, fixtures, and best practices for production-grade shell testing.

When to Use This Skill

  • Writing unit tests for shell scripts
  • Implementing test-driven development (TDD) for scripts
  • Setting up automated testing in CI/CD pipelines
  • Testing edge cases and error conditions
  • Validating behavior across different shell environments
  • Building maintainable test suites for scripts
  • Creating fixtures for complex test scenarios
  • Testing multiple shell dialects (bash, sh, dash)

Detailed patterns and worked examples

Detailed pattern documentation lives in references/details.md. Read that file when the navigation tier above is insufficient.

Testing Error Conditions

#!/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:"* ]]
}

Testing with Dependencies

#!/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 ]
}

Testing Shell Compatibility

#!/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
}

Parallel Execution

#!/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" ]
}

Test Helper Pattern

test_helper.sh

#!/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"
}

Integration with CI/CD

GitHub Actions Workflow

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

Makefile Integration

.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

Best Practices

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

10. Document complex test setup - Explain unusual patterns

Other skills for the same job

different authors, same section of the catalogue
Webapp Testing
by anthropics
vendor ×12

Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs.

6k tokens scripts
Finishing A Development Branch
by ZhanlinCui
×7

Use when implementation is complete, all tests pass, and you need to decide how to integrate the work - guides completion of development work by presenting structured options for merge, PR, or cleanup

1k tokens
Test Driven Development
by w95
×7

Use when implementing any feature or bugfix, before writing implementation code

2k tokens
Systematic Debugging
by ratacat
×7

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes

10k tokens scripts
Verification Before Completion
by ZhanlinCui
×6

Use when about to claim work is complete, fixed, or passing, before committing or creating PRs - requires running verification commands and confirming output before making any success claims; evidence before assertions always

1k tokens
Backtest Expert
by BaggaT236
×3

Expert guidance for systematic backtesting of trading strategies. Use when developing, testing, stress-testing, or validating quantitative trading strategies. Covers "beating ideas to death" methodology, parameter robustness testing, slippage modeling, bias prevention, and interpreting backtest results. Applicable when user asks about backtesting, strategy validation, robustness testing, avoiding overfitting, or systematic trading development.

15k tokens scripts
Adaptyv
by christophacham
×3

Cloud laboratory platform for automated protein testing and validation. Use when designing proteins and needing experimental validation including binding assays, expression testing, thermostability measurements, enzyme activity assays, or protein sequence optimization. Also use for submitting experiments via API, tracking experiment status, downloading results, optimizing protein sequences for better expression using computational tools (NetSolP, SoluProt, SolubleMPNN, ESM), or managing protein design workflows with wet-lab validation.

16k tokens
Aeon
by christophacham
×3

This skill should be used for time series machine learning tasks including classification, regression, clustering, forecasting, anomaly detection, segmentation, and similarity search. Use when working with temporal data, sequential patterns, or time-indexed observations requiring specialized algorithms beyond standard ML approaches. Particularly suited for univariate and multivariate time series analysis with scikit-learn compatible APIs.

19k tokens

How to use it

Copy the folder

Take wshobson/bats-testing-patterns from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.

Install what it needs

The instructions reference npm. Without those the skill loads but fails at the first command.