truth.js

const Assertion = require('../assert')
const AssertionFailedError = require('./error')
const { template } = require('../utils')
const output = require('../output')

class TruthAssertion extends Assertion {
  constructor(params) {
    super(value => {
      if (Array.isArray(value)) {
        return value.filter(val => !!val).length > 0
      }
      return !!value
    }, params)
    this.params.type = this.params.type || 'to be true'
  }

  getException() {
    const err = new AssertionFailedError(this.params, '{{customMessage}}expected {{subject}} {{type}}')
    err.cliMessage = () => {
      const msg = err.template.replace('{{subject}}', output.colors.bold('{{subject}}'))
      return template(msg, this.params)
    }
    return err
  }

  addAssertParams() {
    this.params.value = this.params.actual = arguments[0]
    this.params.expected = true
    this.params.customMessage = arguments[1] ? `${arguments[1]}\n\n` : ''
  }
}

module.exports = {
  Assertion: TruthAssertion,
  truth: (subject, type) => new TruthAssertion({ subject, type }),
}