setValue triggering "ReferenceError: $set is not defined"

[wspringer]

Version

1.0.0-beta.29

Reproduction link

https://circleci.com/gh/wspringer/vue-autoextra/4

Steps to reproduce

Note that even though the test claim to be succesful, they are not.

My component is using scoped slots. If I'm setting a value on an input that has an associated model, then the first bit of setValue — setting the element's value — is okay, but when the 'input' trigger is fired, it produces this error:

console.error node_modules/vue/dist/vue.runtime.common.dev.js:621
    [Vue warn]: Error in v-on handler: "ReferenceError: $set is not defined"

    (found in <Root>)

  console.error node_modules/vue/dist/vue.runtime.common.dev.js:1884
    ReferenceError: $set is not defined
        at input (eval at createFunction (/Users/wilfred/workspace/vue-autoextra/node_modules/vue-template-compiler/build.js:4623:12), <anonymous>:3:288)
        at invokeWithErrorHandling (/Users/wilfred/workspace/vue-autoextra/node_modules/vue/dist/vue.runtime.common.dev.js:1850:26)
        at HTMLInputElement.invoker (/Users/wilfred/workspace/vue-autoextra/node_modules/vue/dist/vue.runtime.common.dev.js:2175:14)
        at HTMLInputElement.original._wrapper (/Users/wilfred/workspace/vue-autoextra/node_modules/vue/dist/vue.runtime.common.dev.js:6889:25)
        at invokeEventListeners (/Users/wilfred/workspace/vue-autoextra/node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:193:27)
        at HTMLInputElementImpl._dispatch (/Users/wilfred/workspace/vue-autoextra/node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:119:9)
        at HTMLInputElementImpl.dispatchEvent (/Users/wilfred/workspace/vue-autoextra/node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:82:17)
        at HTMLInputElementImpl.dispatchEvent (/Users/wilfred/workspace/vue-autoextra/node_modules/jsdom/lib/jsdom/living/nodes/HTMLElement-impl.js:30:27)
        at HTMLInputElement.dispatchEvent (/Users/wilfred/workspace/vue-autoextra/node_modules/jsdom/lib/jsdom/living/generated/EventTarget.js:157:21)
        at Wrapper.trigger (/Users/wilfred/workspace/vue-autoextra/node_modules/@vue/test-utils/dist/vue-test-utils.js:3759:16)
        at Wrapper.setValue (/Users/wilfred/workspace/vue-autoextra/node_modules/@vue/test-utils/dist/vue-test-utils.js:3722:10)
        at VueComponent.<anonymous> (/Users/wilfred/workspace/vue-autoextra/src/component.test.js:38:18)
        at Array.<anonymous> (/Users/wilfred/workspace/vue-autoextra/node_modules/vue/dist/vue.runtime.common.dev.js:1976:12)
        at flushCallbacks (/Users/wilfred/workspace/vue-autoextra/node_modules/vue/dist/vue.runtime.common.dev.js:1902:14)
        at process._tickCallback (internal/process/next_tick.js:68:7)

What is expected?

I'm expecting to be able to call setValue without a problem.

What is actually happening?

The trigger is not firing, causing the model to not be updated.

---

The test is here: https://github.com/wspringer/vue-autoextra/blob/master/src/component.test.js
The component getting tested is here: https://github.com/wspringer/vue-autoextra/blob/master/src/component.js
The expected behavior is demonstrated here: https://medium.com/east-pole/from-angular-to-vue-fb22c7ffab21

[wspringer]

Okay, this more self-contained test also fails with the same error about $set not being defined.

  it('should be okay using a slot', () => {
    const SlotComponent = {
      props: ['person'],
      template: `
      <em><slot :person="person"/></em>
      `.trim()
    }    
    const person = { name: 'Wilfred' }
    const wrapped = mount(SlotComponent, {
      scopedSlots: {
        default: '<input type="text" v-model="props.person.name"/>'
      },
      propsData: {
        "person": person
      }
    })
    expect(wrapped.findAll('input').length).toEqual(1)
    const control = wrapped.findAll('input').at(0)
    control.setValue('Charles')
    expect(person.name).toEqual('Charles')
  })