Add support for TypeScript

index.d.ts

@@ -0,0 +1,19 @@
+import { cleanup, act, RenderOptions, RenderResult } from 'react-testing-library'
+
+export function renderHook<T extends (...args: any[]) => any>(
+  callback: T,
+  options?: {
+    initialProps?: Parameters<T>[0]
+    options?: RenderOptions
+  }
+): {
+  readonly result: {
+    current: ReturnType<T>
+  }
+  readonly unmount: RenderResult['unmount']
+  readonly rerender: (hookProps?: Parameters<T>[0]) => void
+}
+
+export const testHook: typeof renderHook
+
+export { cleanup, act }

package.json

@@ -3,6 +3,7 @@
   "version": "0.3.4",
   "description": "Simple component wrapper for testing React hooks",
   "main": "lib/index.js",
+  "typings": "./index.d.ts",
   "author": "Michael Peyper",
   "repository": {
     "type": "git",
@@ -26,6 +27,7 @@
     "@babel/plugin-transform-modules-commonjs": "^7.2.0",
     "@babel/preset-env": "^7.3.4",
     "@babel/preset-react": "^7.0.0",
+    "@types/react": "^16.8.5",
     "all-contributors-cli": "^6.1.2",
     "babel-eslint": "^10.0.1",
     "babel-plugin-module-resolver": "^3.2.0",
@@ -39,7 +41,9 @@
     "prettier-eslint": "^8.8.2",
     "prettier-eslint-cli": "^4.7.1",
     "react": "^16.8.3",
-    "react-dom": "^16.8.3"
+    "react-dom": "^16.8.3",
+    "typescript": "^3.3.3333",
+    "typings-tester": "^0.3.2"
   },
   "peerDependencies": {
     "react": "^16.8.0",

test/typescript.test.js

@@ -0,0 +1,7 @@
+import { checkDirectory } from 'typings-tester'
+
+describe('TypeScript definitions', function() {
+  it('should compile against index.d.ts', () => {
+    checkDirectory(__dirname + '/typescript')
+  })
+})

test/typescript/renderHook.ts

@@ -0,0 +1,60 @@
+import { useState, createContext, useContext, useMemo } from 'react'
+import { renderHook } from 'react-hooks-testing-library'
+
+const DARK: 'dark' = 'dark'
+const LIGHT: 'light' = 'light'
+
+type InitialTheme = typeof DARK | typeof LIGHT | undefined
+
+const themes = {
+  light: { primaryLight: '#FFFFFF', primaryDark: '#000000' },
+  dark: { primaryLight: '#000000', primaryDark: '#FFFFFF' }
+}
+
+const ThemesContext = createContext(themes)
+
+const useTheme = (initialTheme: InitialTheme = DARK) => {
+  const themes = useContext(ThemesContext)
+  const [theme, setTheme] = useState(initialTheme)
+  const toggleTheme = () => {
+    setTheme(theme === 'light' ? 'dark' : 'light')
+  }
+  return useMemo(() => ({ ...themes[theme], toggleTheme }), [theme])
+}
+
+type InitialProps = { initialTheme: InitialTheme }
+
+function checkTypesWithNoInitialProps() {
+  const { result, unmount, rerender } = renderHook(() => useTheme())
+
+  // check types
+  const _result: {
+    current: {
+      primaryDark: string
+      primaryLight: string
+      toggleTheme: () => void
+    }
+  } = result
+  const _unmount: () => boolean = unmount
+  const _rerender: () => void = rerender
+}
+
+function checkTypesWithInitialProps() {
+  const { result, unmount, rerender } = renderHook(
+    ({ initialTheme }: InitialProps) => useTheme(initialTheme),
+    {
+      initialProps: { initialTheme: DARK }
+    }
+  )
+
+  // check types
+  const _result: {
+    current: {
+      primaryDark: string
+      primaryLight: string
+      toggleTheme: () => void
+    }
+  } = result
+  const _unmount: () => boolean = unmount
+  const _rerender: (_: InitialProps) => void = rerender
+}

test/typescript/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "lib": ["es2015", "dom"],
+    "strict": true,
+    "baseUrl": "../../",
+    "paths": {
+      "react-hooks-testing-library": ["index.d.ts"]
+    }
+  }
+}