feat(typings): add ts definitions

Author: Miklet

package.json

@@ -3,6 +3,7 @@
   "version": "0.0.0-semantically-released",
   "description": "Simple and complete React DOM testing utilities that encourage good testing practices.",
   "main": "dist/index.js",
+  "typings": "typings/index.d.ts",
   "engines": {
     "node": ">=8",
     "npm": ">=5"
@@ -25,6 +26,7 @@
   "license": "MIT",
   "dependencies": {},
   "devDependencies": {
+    "@types/react-dom": "^16.0.4",
     "axios": "^0.18.0",
     "history": "^4.7.2",
     "kcd-scripts": "^0.36.1",
@@ -58,4 +60,4 @@
     "url": "https://github.com/kentcdodds/react-testing-library/issues"
   },
   "homepage": "https://github.com/kentcdodds/react-testing-library#readme"
-}
+}

typings/index.d.ts

@@ -0,0 +1,16 @@
+import {Simulate as ReactSimulate} from 'react-dom/test-utils'
+
+interface RenderResult {
+  container: HTMLDivElement
+  unmount: VoidFunction
+  queryByTestId: (id: string) => HTMLElement | null
+}
+
+export function render(
+  ui: React.ReactElement<any>,
+  options?: {container: HTMLElement},
+): RenderResult
+
+export function flushPromises(): Promise<void>
+
+export const Simulate: typeof ReactSimulate