From 385a28ed029d12b27d5fc0c8f6e9ffdef02dad56 Mon Sep 17 00:00:00 2001
From: Sebastian Silbermann <silbermann.sebastian@gmail.com>
Date: Tue, 30 Jul 2019 09:04:23 +0000
Subject: [PATCH 1/2] feat: Add act

---
 src/index.js      |  9 +++++++++
 tests/act.spec.js | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 tests/act.spec.js

diff --git a/src/index.js b/src/index.js
index 9cd3ce9..6d89398 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,4 +1,5 @@
 import {getQueriesForElement, prettyDOM} from '@testing-library/dom'
+import {tick} from 'svelte'
 
 export * from '@testing-library/dom'
 const mountedContainers = new Set()
@@ -36,3 +37,11 @@ const cleanupAtContainer = container => {
 export const cleanup = () => {
   mountedContainers.forEach(cleanupAtContainer)
 }
+
+export function act(fn) {
+  const returnValue = fn()
+  if (returnValue != null && typeof returnValue.then === 'function') {
+    return returnValue.then(() => tick())
+  }
+  return tick()
+}
diff --git a/tests/act.spec.js b/tests/act.spec.js
new file mode 100644
index 0000000..96931a1
--- /dev/null
+++ b/tests/act.spec.js
@@ -0,0 +1,35 @@
+import {act, render, fireEvent, cleanup} from '../src'
+import App from './example/App.svelte'
+import 'jest-dom/extend-expect'
+
+afterEach(cleanup)
+
+test('after awaited state updates are flushed', async () => {
+  const {getByText} = render(App, {props: {name: 'world'}})
+  const button = getByText('Button Text')
+
+  const acting = act(() => {
+    fireEvent.click(button)
+  })
+  expect(button).toHaveTextContent('Button Text')
+
+  await acting
+  expect(button).toHaveTextContent('Button Clicked')
+})
+
+test('accepts async functions', async () => {
+  function sleep(ms) {
+    return new Promise(resolve => {
+      setTimeout(() => resolve(), ms)
+    })
+  }
+
+  const {getByText} = render(App, {props: {name: 'world'}})
+  const button = getByText('Button Text')
+
+  await act(async () => {
+    await sleep(100)
+    fireEvent.click(button)
+  })
+  expect(button).toHaveTextContent('Button Clicked')
+})

From 50fcae7c7a8aff201e865131c9742fec9be10c68 Mon Sep 17 00:00:00 2001
From: Sebastian Silbermann <silbermann.sebastian@gmail.com>
Date: Mon, 5 Aug 2019 19:57:48 +0200
Subject: [PATCH 2/2] Expect nothing to be returned or thenable

---
 src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 6d89398..6ef0282 100644
--- a/src/index.js
+++ b/src/index.js
@@ -40,7 +40,7 @@ export const cleanup = () => {
 
 export function act(fn) {
   const returnValue = fn()
-  if (returnValue != null && typeof returnValue.then === 'function') {
+  if (returnValue !== undefined && typeof returnValue.then === 'function') {
     return returnValue.then(() => tick())
   }
   return tick()