fix: improve warning so people know they can upgrade to 16.9.0 now

Closes #281

Author: Kent C. Dodds

package.json

@@ -41,17 +41,17 @@
   "author": "Kent C. Dodds <[email protected]> (http://kentcdodds.com/)",
   "license": "MIT",
   "dependencies": {
-    "@babel/runtime": "^7.5.4",
-    "@testing-library/dom": "^5.5.4"
+    "@babel/runtime": "^7.5.5",
+    "@testing-library/dom": "^5.6.1"
   },
   "devDependencies": {
     "@reach/router": "^1.2.1",
     "@testing-library/jest-dom": "^4.0.0",
-    "@types/react": "^16.8.23",
-    "@types/react-dom": "^16.8.4",
+    "@types/react": "^16.8.25",
+    "@types/react-dom": "^16.8.5",
     "kcd-scripts": "^1.5.2",
-    "react": "^16.8.6",
-    "react-dom": "^16.8.6"
+    "react": "^16.9.0",
+    "react-dom": "^16.9.0"
   },
   "peerDependencies": {
     "react": "*",

src/__tests__/old-act.js

@@ -10,10 +10,6 @@ afterEach(() => {
   console.error.mockRestore()
 })
 
-jest.mock('../react-dom-16.9.0-is-released', () => ({
-  reactDomSixteenPointNineIsReleased: true,
-}))
-
 jest.mock('react-dom/test-utils', () => ({
   act: cb => {
     cb()

src/act-compat.js

@@ -1,7 +1,6 @@
 import React from 'react'
 import ReactDOM from 'react-dom'
 import * as testUtils from 'react-dom/test-utils'
-import {reactDomSixteenPointNineIsReleased} from './react-dom-16.9.0-is-released'
 
 const reactAct = testUtils.act
 const actSupported = reactAct !== undefined
@@ -76,7 +75,7 @@ function asyncAct(cb) {
         if (isAsyncActSupported === false) {
           console.error = originalConsoleError
           /* istanbul-ignore-next */
-          if (!youHaveBeenWarned && reactDomSixteenPointNineIsReleased) {
+          if (!youHaveBeenWarned) {
             // if act is supported and async act isn't and they're trying to use async
             // act, then they need to upgrade from 16.8 to 16.9.
             // This is a seemless upgrade, so we'll add a warning