externalproperty

Callable

• property<Actual, PropertyName>(propertyName: PropertyName, expectation: Expectation<Actual[PropertyName]>): Expectation<Actual>

---

• Creates an expectation that is met when the value of the actual[propertyName] meets the expectation.

  Ensuring that an array has an item

  import { actorCalled } from '@serenity-js/core'
  import { Ensure, property } from '@serenity-js/assertions'
  
  const list = [ 'hello', 'world' ]
  
  await actorCalled('Ester').attemptsTo(
    Ensure.that(list, property(0, isPresent())),
  )

  Ensuring that the property meets an expectation

  import { actorCalled } from '@serenity-js/core'
  import { Ensure, property, equals } from '@serenity-js/assertions'
  
  const list = [ 'hello', 'world' ]
  
  await actorCalled('Ester').attemptsTo(
    Ensure.that(list, property('length', equals(2))),
  )

  Asserting on a list of objects

  import { actorCalled } from '@serenity-js/core'
  import { Ensure, property, equals } from '@serenity-js/assertions'
  
  const developers = [{
      name: 'Jan',
      id: '@jan-molak',
  }, {
      name: 'John',
      id: '@wakaleo',
  }]
  
  await actorCalled('Ester').attemptsTo(
    Ensure.that(
      developers,
      containItemsWhereEachItem(
        property('id', startsWith('@'))
      ),
    ),
  )

  ---

  Type parameters

  • Actual: object
  • PropertyName: string | number | symbol

  Parameters

  • externalpropertyName: PropertyName

  • externalexpectation: Expectation<Actual[PropertyName]>

  Returns Expectation<Actual>