slot-scope doesn't accept all valid expressions

[smiller171]

Version

dev branch

Reproduction link

https://codesandbox.io/s/mow3jyo89j?module=%2Ftest%2Funit%2Fspecs%2FScoped-broken.spec.js&view=preview

Steps to reproduce

Access a scope with a JS expression like "{ item }" instead of "item"

What is expected?

Using "{ item }" to identify a scope should allow for accessing that variable directly instead of having to use something.item

What is actually happening?

item is not defined

ReferenceError: item is not defined
    at Object.eval (eval at createFunction (https://mow3jyo89j.codesandbox.io/node_modules/vue-template-compiler/browser.js), :3:39)
    at Proxy.vm._renderProxy._t (https://mow3jyo89j.codesandbox.io/node_modules/@millergeek/test-utils/dist/vue-test-utils.js:1931:31)
    at eval (https://mow3jyo89j.codesandbox.io/src/components/Scoped.vue?f8cd7dd6:1:334)
    at Proxy.renderList (https://mow3jyo89j.codesandbox.io/node_modules/vue/dist/vue.common.js:3707:16)
    at Proxy.render (https://mow3jyo89j.codesandbox.io/src/components/Scoped.vue?f8cd7dd6:1:273)
    at VueComponent.Vue._render (https://mow3jyo89j.codesandbox.io/node_modules/vue/dist/vue.common.js:4546:22)
    at VueComponent.updateComponent (https://mow3jyo89j.codesandbox.io/node_modules/vue/dist/vue.common.js:2790:21)
    at Watcher.get (https://mow3jyo89j.codesandbox.io/node_modules/vue/dist/vue.common.js:3144:25)
    at new Watcher (https://mow3jyo89j.codesandbox.io/node_modules/vue/dist/vue.common.js:3133:12)
    at mountComponent (https://mow3jyo89j.codesandbox.io/node_modules/vue/dist/vue.common.js:2797:3)
    at VueComponent.Vue.$mount (https://mow3jyo89j.codesandbox.io/node_modules/vue/dist/vue.common.js:8542:10)
    at VueComponent.Vue.$mount (https://mow3jyo89j.codesandbox.io/node_modules/vue/dist/vue.common.js:10941:16)
    at mount (https://mow3jyo89j.codesandbox.io/node_modules/@millergeek/test-utils/dist/vue-test-utils.js:4744:8)
    at shallow (https://mow3jyo89j.codesandbox.io/node_modules/@millergeek/test-utils/dist/vue-test-utils.js:4781:10)
    at eval (https://mow3jyo89j.codesandbox.io/test/unit/specs/Scoped-broken.spec.js:14:36)
    at s (https://codesandbox.io/static/js/sandbox.153e4095.js:2529:310)
    at o (https://codesandbox.io/static/js/sandbox.153e4095.js:2529:124)
    at evaluate (https://mow3jyo89j.codesandbox.io/test/unit/specs/Scoped-broken.spec.js:13:1)
    at r.a (https://codesandbox.io/static/js/sandbox.153e4095.js:5354:971)
    at e.value (https://codesandbox.io/static/js/sandbox.153e4095.js:5413:270)
    at e.value (https://codesandbox.io/static/js/sandbox.153e4095.js:5386:23195)
    at e.value (https://codesandbox.io/static/js/sandbox.153e4095.js:5386:22974)
    at e. (https://codesandbox.io/static/js/sandbox.153e4095.js:5386:18687)
    at n (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:2847:811)
    at Generator._invoke (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:2847:599)
    at Generator.e.(anonymous function) [as next] (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:2847:990)
    at o (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:3049:316)
    at https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:3049:464
    at new Promise ()
    at new t (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:678:776)
    at https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:3049:258
    at https://codesandbox.io/static/js/sandbox.153e4095.js:5386:18996
    at Array.map ()
    at e. (https://codesandbox.io/static/js/sandbox.153e4095.js:5386:18550)
    at n (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:2847:811)
    at Generator._invoke (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:2847:599)
    at Generator.e.(anonymous function) [as next] (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:2847:990)
    at o (https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:3049:316)
    at https://codesandbox.io/static/js/common-sandbox.d83f0a59.js:3049:412
Console
6
Problems
4

---

I had to fork and build vue-test-utils myself to find this bug on the dev branch. Am happy to update with the official beta15 on Monday.

[38elements]

I will send a pull request to resolve this issue within a day.

[eddyerburgh]

This has been