fix: trim slot when passed a string

Author: lmiller1990

src/mount.ts

@@ -236,7 +236,7 @@ export function mount(
 
         if (typeof slot === 'string') {
           // slot is most probably a scoped slot string or a plain string
-          acc[name] = (props: VNodeProps) => h(processSlot(slot), props)
+          acc[name] = (props: VNodeProps) => h(processSlot(slot.trim()), props)
           return acc
         }
 

tests/mountingOptions/slots.spec.ts

@@ -141,9 +141,13 @@ describe('slots', () => {
     })
 
     it('allows passing a scoped slot via string with no destructuring using the v-slot syntax ', () => {
+      // Note: there is intentionally a carriage return after the first ` in the scoped key.
+      // https://github.com/vuejs/vue-test-utils-next/issues/202
       const wrapper = mount(ComponentWithSlots, {
         slots: {
-          scoped: `<template v-slot:scoped="params"><div>Just a plain {{ params.boolean }} {{ params.string }}</div></template>`
+          scoped: `
+            <template v-slot:scoped="params"><div>Just a plain {{ params.boolean }} {{ params.string }}</div></template>
+          `
         }
       })