add-scoped-slots.js

// @flow
import { compileToFunctions } from 'vue-template-compiler'
import { throwError, vueVersion } from 'shared/util'

function isDestructuringSlotScope (slotScope: string): boolean {
  return slotScope[0] === '{' && slotScope[slotScope.length - 1] === '}'
}

function getVueTemplateCompilerHelpers (proxy: Object): Object {
  const helpers = {}
  const names = [
    '_c',
    '_o',
    '_n',
    '_s',
    '_l',
    '_t',
    '_q',
    '_i',
    '_m',
    '_f',
    '_k',
    '_b',
    '_v',
    '_e',
    '_u',
    '_g'
  ]
  names.forEach(name => {
    helpers[name] = proxy[name]
  })
  return helpers
}

export function addScopedSlots (
  vm: Component,
  scopedSlots: { [name: string]: string }
): void {
  if (window.navigator.userAgent.match(/PhantomJS/i)) {
    throwError(
      `the scopedSlots option does not support PhantomJS. ` +
        `Please use Puppeteer, or pass a component.`
    )
  }

  if (vueVersion < 2.5) {
    throwError(`the scopedSlots option is only supported in ` + `vue@2.5+.`)
  }
  vm.$_vueTestUtils_scopedSlots = {}
  vm.$_vueTestUtils_slotScopes = {}
  const renderSlot = vm._renderProxy._t

  vm._renderProxy._t = function (name, feedback, props, bindObject) {
    const scopedSlotFn = vm.$_vueTestUtils_scopedSlots[name]
    const slotScope = vm.$_vueTestUtils_slotScopes[name]
    if (scopedSlotFn) {
      props = { ...bindObject, ...props }
      const helpers = getVueTemplateCompilerHelpers(vm._renderProxy)
      let proxy = { ...helpers }
      if (isDestructuringSlotScope(slotScope)) {
        proxy = { ...helpers, ...props }
      } else {
        proxy[slotScope] = props
      }
      return scopedSlotFn.call(proxy)
    } else {
      return renderSlot.call(
        vm._renderProxy,
        name,
        feedback,
        props,
        bindObject
      )
    }
  }

  Object.keys(scopedSlots).forEach(key => {
    const template = scopedSlots[key].trim()
    if (template.substr(0, 9) === '<template') {
      throwError(
        `the scopedSlots option does not support a template ` +
          `tag as the root element.`
      )
    }
    const domParser = new window.DOMParser()
    const _document = domParser.parseFromString(template, 'text/html')
    vm.$_vueTestUtils_scopedSlots[key] = compileToFunctions(template).render
    vm.$_vueTestUtils_slotScopes[key] = _document.body.firstChild.getAttribute(
      'slot-scope'
    )
  })
}