CLI Testing Patterns

Comprehensive testing strategies for CLI applications using industry-standard testing frameworks. Covers command execution testing, exit code validation, output verification, interactive prompt testing, and integration testing patterns.

Instructions

When Testing Node.js CLI Tools

1. Use Jest for testing CLI commands

   • Import child_process.execSync for command execution
   • Create helper function to run CLI and capture output
   • Test exit codes, stdout, stderr separately
   • Handle both success and error cases

2. Test Structure

   • Set up CLI path relative to test location
   • Create runCLI() helper that returns {stdout, stderr, code}
   • Use try-catch to handle non-zero exit codes
   • Test common scenarios: version, help, unknown commands