@coriolis/coriolis/src/test/eventBuilder.spec.js

Event sourced effect management

import { createEventBuilder } from '../eventBuilder'
import { expect } from 'chai'

describe('eventBuilder', () => {
  it('Creates event with only a type', () => {
    const eventBuilder = createEventBuilder('eventType')

    const event = eventBuilder()

    expect(event).to.deep.equal({ type: 'eventType' })
  })

  it('Gives easy access to event type', () => {
    const eventBuilder = createEventBuilder('eventType')

    expect(eventBuilder.toString()).to.equal('eventType')
  })

  it('Creates event with a payload used as is from builder params', () => {
    const eventBuilder = createEventBuilder('eventType')

    const event = eventBuilder({ any: 'value' })

    expect(event).to.deep.equal({
      type: 'eventType',
      payload: { any: 'value' },
    })
  })

  it('Creates event with a payload computed from builder params', () => {
    const eventBuilder = createEventBuilder(
      'eventType',
      ({ arg1, arg2, arg3 }) => [arg1, arg2, arg3],
    )

    const event = eventBuilder({
      arg1: { any: 'value1' },
      arg2: { any: 'value2' },
      arg3: { any: 'value3' },
    })

    expect(event).to.deep.equal({
      type: 'eventType',
      payload: [{ any: 'value1' }, { any: 'value2' }, { any: 'value3' }],
    })
  })

  it('Creates event with payload and meta', () => {
    const eventBuilder = createEventBuilder(
      'eventType',
      ({ arg }) => arg,
      ({ meta }) => meta,
    )

    const event = eventBuilder({ arg: 'value', meta: 'meta' })

    expect(event).to.deep.equal({
      type: 'eventType',
      payload: 'value',
      meta: 'meta',
    })
  })

  it('Adds error boolean in case payload is an Error instance', () => {
    const error = new Error('test error')
    const eventBuilder = createEventBuilder(
      'eventType',
      sinon.stub().returns(error),
    )

    const event = eventBuilder()

    expect(event).to.deep.equal({
      type: 'eventType',
      payload: error,
      error: true,
    })
  })

  it('Handles errors while building payload, creating an error event', () => {
    const error = new Error('test error')
    const eventBuilder = createEventBuilder(
      'eventType',
      sinon.stub().throws(error),
    )

    const event = eventBuilder()

    expect(event).to.deep.equal({
      type: 'eventType',
      payload: error,
      error: true,
    })
  })

  it('Handles errors while building meta, creating an error event', () => {
    const error = new Error('test error')
    const eventBuilder = createEventBuilder(
      'eventType',
      () => ({}),
      sinon.stub().throws(error),
    )

    const event = eventBuilder()

    expect(event).to.deep.equal({
      type: 'eventType',
      payload: error,
      error: true,
    })
  })
})