fix(TS): act type (#438)

* fix(types): Use act types from react-dom

* Fix unary not extending binary

Author: eps1lon

package.json

@@ -44,7 +44,8 @@
   "license": "MIT",
   "dependencies": {
     "@babel/runtime": "^7.5.5",
-    "@testing-library/dom": "^6.0.0"
+    "@testing-library/dom": "^6.0.0",
+    "@types/react-dom": "*"
   },
   "devDependencies": {
     "@reach/router": "^1.2.1",

typings/index.d.ts

@@ -1,4 +1,5 @@
 import {queries, Queries, BoundFunction} from '@testing-library/dom'
+import {act as reactAct} from 'react-dom/test-utils'
 
 export * from '@testing-library/dom'
 
@@ -43,4 +44,6 @@ export function cleanup(): void
  * If that's not available (older version of react) then it
  * simply calls the given callback immediately
  */
-export function act(callback: () => void): void
+export const act: typeof reactAct extends undefined
+  ? (callback: () => void) => void
+  : typeof reactAct