Example issue - undefined parameter

[lucfranken]

In this example:

json-rules-engine/examples/01-hello-world.js

Line 52 in 0de797c

events.map(event => console.log(event.params.data.green))

It seems that the example is wrong as it uses a parameter "green" which is not on the event params:

'use strict'
/*
 * This is the hello-world example from the README.
 *
 * Usage:
 *   node ./examples/01-hello-world.js
 *
 * For detailed output:
 *   DEBUG=json-rules-engine node ./examples/01-hello-world.js
 */

require('colors')
const { Engine } = require('json-rules-engine')

async function start () {
  /**
   * Setup a new engine
   */
  const engine = new Engine()

  /**
   * Create a rule
   */
  engine.addRule({
    // define the 'conditions' for when "hello world" should display
    conditions: {
      all: [{
        fact: 'displayMessage',
        operator: 'equal',
        value: true
      }]
    },
    // define the 'event' that will fire when the condition evaluates truthy
    event: {
      type: 'message',
      params: {
        data: 'hello-world!'
      }
    }
  })

  /**
   * Define a 'displayMessage' as a constant value
   * Fact values do NOT need to be known at engine runtime; see the
   * 03-dynamic-facts.js example for how to pull in data asynchronously during runtime
   */
  const facts = { displayMessage: true }

  // engine.run() evaluates the rule using the facts provided
  const { events } = await engine.run(facts)

  events.map(event => console.log(event.params.data.green))
}

start()
/*
 * OUTPUT:
 *
 * hello-world!
 */

I think this:

events.map(event => console.log(event.params.data.green))
Should be:

events.map(event => console.log(event.params.data))

Then the example runs fine. I am just starting with the library so I may miss some logic, that's why just posting it as an issue.

[chris-pardy]

@lucfranken does the example fail when you run it without that change?
The .green property is being added to the String prototype by the colors library which emits terminal color information.
Because data is a string it should have the .green property. However if you change the type of data, or omit requiring the colors library then this won't work.