asl-validator's Introduction

asl-validator

A simple Amazon States Language validator based on JSON schemas. It also validates JSON paths syntax in InputPath, OutputPath and ResultPath.

When writing your state machine (for AWS step functions), you can't locally validate you state machine definition without creating it. asl-validator makes it possible.

Install

# Use via the CLI
npm install -g asl-validator
# Use in your code
npm install asl-validator

CLI

$ asl-validator --help

  Usage: asl-validator [options]

  Amazon States Language validator


  Options:

    -v, --version                       output the version number
    --json-definition <jsonDefinition>  JSON definition
    --json-path <jsonPath>              JSON path
    --silent                            silent mode
    -h, --help                          output usage information

Return status:

0 if state machine definition is valid
1 if state machine definition is invalid
2 if an exception occurs

In your code

const aslValidator = require('asl-validator');
const definition = require('./path/to/my/state/machine/json/definition');
const { isValid, errors, errorsText } = aslValidator(definition);
if (isValid) {
  console.log('✓ State machine definition is valid')
} else {
  // Either go through the errors object
  console.error('✕ State machine definition is invalid:', errors.map(({ message }) => message).join('\n'));
  // Or display the preformatted errors text
  console.error('✕ State machine definition is invalid:', errorsText('\n'));
}