Fixed styles inserted by <Global/> component not inheriting `speedy…

…` option (#1734)

.changeset/dry-frogs-perform.md

@@ -0,0 +1,5 @@
+---
+'@emotion/react': patch
+---
+
+Fixed styles inserted by `<Global/>` component not inheriting `speedy` option from a cache passed to a wrapping `<CacheProvider/>`.

packages/react/__tests__/css.js

@@ -1,8 +1,9 @@
 // @flow
 /** @jsx jsx */
 import 'test-utils/next-env'
+import { safeQuerySelector } from 'test-utils'
 import * as React from 'react'
-import { jsx, css, CacheProvider, ThemeProvider } from '@emotion/react'
+import { jsx, css, Global, CacheProvider, ThemeProvider } from '@emotion/react'
 import { render } from '@testing-library/react'
 import renderer from 'react-test-renderer'
 import createCache from '@emotion/cache'
@@ -14,6 +15,7 @@ console.warn = jest.fn()
 
 afterEach(() => {
   jest.clearAllMocks()
+  safeQuerySelector('body').innerHTML = ''
 })
 
 const SomeComponent = (props: { lol: true }) => (props.lol ? 'yes' : 'no')
@@ -173,6 +175,19 @@ test('can set speedy via custom cache', () => {
   expect(cache.sheet.tags).toHaveLength(1)
 })
 
+test('speedy option from a custom cache is inherited for <Global/> styles', () => {
+  let cache = createCache({
+    container: safeQuerySelector('body'),
+    speedy: true
+  })
+  renderer.create(
+    <CacheProvider value={cache}>
+      <Global styles={{ html: { fontSize: 16 } }} />>
+    </CacheProvider>
+  )
+  expect(safeQuerySelector('body style').textContent).toEqual('')
+})
+
 test('autoLabel without babel', () => {
   let SomeComp = props => {
     return (

packages/react/src/global.js

@@ -92,7 +92,8 @@ export let Global: React.AbstractComponent<
       let sheet = new StyleSheet({
         key: `${cache.key}-global`,
         nonce: cache.sheet.nonce,
-        container: cache.sheet.container
+        container: cache.sheet.container,
+        speedy: cache.sheet.isSpeedy
       })
       // $FlowFixMe
       let node: HTMLStyleElement | null = document.querySelector(